Help with low efficiency with BIAB

[CaptainCookie]

Hi everybody, I'm having efficiency troubles in my batches, I getting nearly 50 - 55% efficiency, I use a very simple BIAB setup, just a 5 gallons kettle and the typical BIAB bag, I might guess what it's the problem, but I want your opinions as well

Right now I'm discarding all other factors, so I just want to center in this point:

About the Lift, Drain, and Squeeze, after the sparge, I just lift the bag and discard it, no draining whatsoever, I'm guessing that's the main problem, about how long is recommendable for draining for a 5 gallons batch? this could be the critical flat in my efficiency? and what about squeeze?, again, I don't squeeze the bag whatsoever, I'm pretty worried about the tannins extraction, is squeezing mandatory in BIAB or you can just avoid it?, again, pretty concern about tannins

Thanks

 

[soccerdad]

Forget about tannins. 99.99999% of the time it will not be an issue.

But say more about your process. You mention biab and sparge. How are you mashing and sparging with the bag? Details. How many kettles and buckets, how many pounds of grain, who crushes it, how many gallons mash v. sparge. There is good help here, but knowing more means better help.

 

[wilserbrewer]

As Doug said a while back, the 3 most likely causes of low efficiency are
1 crush
2 crush
3 crush

How is your crush?

Post a pic of your grist?

 

[boomerbrian]

Tannins aren't an issue when you squeeze the bag.

 

[shoengine]

I had a similar efficiency in my time-before-last BIAB session. I'll paste it in here in case it helps.

https://www.homebrewtalk.com/showthread.php?t=632577

I went from something like 49% to 89% efficiency.

 

[yourlastchance89]

Tannins aren't an issue when you squeeze the bag.

I've never had an issue with tannins, but I have noticed squeezing does produce an irreversible haze in my beers. If they're not a darker beer or a NEIPA I just hang and drain

 

[doug293cz]

I've never had an issue with tannins, but I have noticed squeezing does produce an irreversible haze in my beers. If they're not a darker beer or a NEIPA I just hang and drain

Gelatin in the keg can cure that haze (at least it does for me.)

Brew on

 

[Oginme]

I've never had an issue with tannins, but I have noticed squeezing does produce an irreversible haze in my beers. If they're not a darker beer or a NEIPA I just hang and drain

I am an aggressive squeezer and have not had any issues with getting clear, bright pale beers and lagers. I use Irish moss towards the end of the boil and a 4 to 6 day cold crash (<40F) at the end of fermentation. Getting a good cold break during chilling the wort is critical as well.

 

[Mordhaus]

Are you milling your own grain? I mill my own and have the gap set at .018". If you're having someone else mill it, the crush is most likely going to be optimal for those who have to worry about stuck sparges. You use a bag and don't have that issue. Crush the hell out of it. Buy a comically large whisk for doughing in and don't be afraid to stir a couple of times during the mash.

In addition, buy some silicone heat resistant gloves and squeeze the bag for all it's got. Do these things and I guarantee you'll gain at least 20 points on your efficiency.

 

[doug293cz]

As Doug said a while back, the 3 most likely causes of low efficiency are
1 crush
2 crush
3 crush

How is your crush?

Post a pic of your grist?

Actually, I think it was someone else who said crush, crush, and crush. I don't want to be given credit for another author's unique way of emphasizing the importance of crush. I (and many others) always put crush as the number 1 factor, by a huge margin, but I try not to be redundant (but might not always be successful ).

Brew on

 

[doug293cz]

Hi everybody, I'm having efficiency troubles in my batches, I getting nearly 50 - 55% efficiency, I use a very simple BIAB setup, just a 5 gallons kettle and the typical BIAB bag, I might guess what it's the problem, but I want your opinions as well

Right now I'm discarding all other factors, so I just want to center in this point:

About the Lift, Drain, and Squeeze, after the sparge, I just lift the bag and discard it, no draining whatsoever, I'm guessing that's the main problem, about how long is recommendable for draining for a 5 gallons batch? this could be the critical flat in my efficiency? and what about squeeze?, again, I don't squeeze the bag whatsoever, I'm pretty worried about the tannins extraction, is squeezing mandatory in BIAB or you can just avoid it?, again, pretty concern about tannins

Thanks

Curious how you are doing a 5 gal batch in a 5 gal kettle. Are you adding top up water after the boil? If so, there is a significant efficiency hit when doing all grain that way (unlike extract brewing.)

As has been mentioned already, crush is usually the biggest issue by far in low efficiency cases.

Tannins are not extracted mechanically (i.e by squeezing.) There are commercial breweries that use pneumatic/hydraulic filter presses (super squeezers) to lauter their mashes (Alaskan is one), They wouldn't be doing this if squeezing extracted tannins. Tannins are extracted when the temp gets above about 170°F, AND the pH is above about 6. Keep your pH below 5.8, and you don't have to worry about tannins.

That said, many BIABer's forgo squeezing, and just let the bag drain. In these cases drain times of 20 - 30 minutes are common, and the draining may continue even into the boil. If you are going to sparge, efficiency will be maximized, if you get as much wort out of the bag as possible before you start the sparge.

Brew on

 

[yourlastchance89]

http://brulosophy.com/2017/05/22/br...ag-has-on-beer-character-exbeeriment-results/

 

[njohnsoncs]

I have the same efficiency problem. I have been ordering my grains precrushed. I will crush them further before my next batch but can you crush them too much?

 

[doug293cz]

I have the same efficiency problem. I have been ordering my grains precrushed. I will crush them further before my next batch but can you crush them too much?

Pretty hard to over crush. There are BIABers who use Corona style mills to crush to the level of corn meal, containing a significant fraction which is flour, without issues. You might have problems if you crushed all the grain to the fineness of baking flour.

Brew on

 

[cod3ck]

If it helps -- I just knocked out my first BIAB batch and got low 60's... after double checking the grains after mash, there were dough balls all over...

 

[Smellyglove]

You need to let it drain. Since you're not sparging every drop of liquid withheld in the mash is your highest SG wort. What you can do is let it drain as long as you want to wait, then strain the bag over your fermenter if you're using a bucket, and let it drain off there, and add that wort to the boil. Don't let the bag touch the bottom though, as it will reabsorb what has already been drained.

For example, I don't sparge, but use a false bottom and a dedicated boil kettle. If i drain the wort from the mash in about 30 minutes, then wait maybe 15-20 minutes, I can get about 1L more out of it, which bumps efficiency dramatically comparing to if I'd just discard that 1L. I'm doing preboils of roughly 20L.

When it comes to homebrewing, time is your friend. The more you rush things the more not-as-good-as-can-be will be the result.

 

[CaptainCookie]

Thanks for the feedback guys, you're right, more information could bring more insight about the issue

Here's my brewing schedule

1.- Milling, I mill the grain on my own with a corona grain mill, I hear about people having issues with this type of miller, for me, it works fine, this monday gonna upload a pic of the grist, cuz the miller it's borrowed, maybe a double milling could solve the problem, but kind concern about the stability of the grain bed for sparging

2.-Mashing, Single infusion, I heat the water at 167°F, insert the bag, pour the grain little by little while stir, and leave it for 90 minutes, I'm guessing the drop of temperature during the 90min mashing could be the main problem, cuz I just leave it there, I don't turn on the heater again for avoiding scorching the bag, also no mash out, I use German grain of the brand Bestzmalt, supposedly they are well-suited and enough modified for single infusion, right?

3.- Recirculation, just the typical thing, grab a bucket of wort and pour it through a skimmer for avoiding perforations in the grain bed, nothing fancy

4.- Sparge, I do fly sparging, for my batch of 4.7 gallons it takes me about 10 minutes, that is the maximum volume that I can work with my 5 gallons kettle, I just pour water at 158°F, again, through the skimmer for avoiding perforations, at the same rate of runoff

5.-Lifting the bag, I just lift the bag I discard the grain, no squeezing or draining whatsoever, about the draining, this last amount of wort drained of the bag wouldn't be all cloudy and charge of trub? Won't it affect the clarity of the final beer?

I don't use a mash tun, just collect the all the wort in a big pot, wash the kettle and pour again the wort in the kettle and then boil, whirlpool, cooling and to the fermenter

I use tasteless gelatin instead of Irish moss or whirlfloc tablet, those two are pretty hard to find and expensive here in Perú, but so far with a good cold-crash haven't had haze problems so far

Well, hope this could help to find the flat of efficiency of my process, thanks guys

 

[Smellyglove]

Look into batch sparging. If you just drip the water through the grains you are missing out. Many people try do do a continious sparge, or at least they think they are doing it, but a continious/fly sparge calls for either some equipment, or a lot of patience, and technique if you dont have the equipment do do it for you.

 

[brew703]

Are you really heating your strike water to 167 degrees? if so that is way too high. I normally heat my strike water to 157 to mash at 152 degrees.

Maybe you are using too much water. A miscalculation would dramatically reduce your gravity/efficiency.

I brew 3.5 gal batches (3 gallon to fermenter) and I use 5.6 gallons of water (normally and depending on grain bill/boil times). I usually have less than a quarter gallon remaining in the kettle.

I would definitely start by crushing your grain finer and verify total water used.

For what it's worth, I'm also one who squeezes the bag to a point to obtain my preboil volume. Once I hit that mark, I remove the bag. I also have a pulley system so I can allow the bag to drain but most times I just squeeze and never had an issue with tannins or clarity.

 

[CaptainCookie]

Are you really heating your strike water to 167 degrees? if so that is way too high. I normally heat my strike water to 157 to mash at 152 degrees.

Well I heated the water to 167°F cuz once I pour all the grain, the water temperature descent, and at the end of the 90 min mash it should hit about the 152°F, please correct me if I'm wrong

About water calculation, here's what I use for a 5gallons batch, sorry but for this case, I gonna use metric system, don't know if could be an issue converting to imperial:

For a 20lts batch, I use 5kg grain bill. so:
5x3= 15lts, the grain absorb it's own weight in water, so 15-5= 10lts, so this is my strike water, about sparge, my losses add up to 3.35lts, in boil-off, contraction, trub loss and kettle loss, so my final volumen should be 23.35lts

therefore, for sparge it's 13.35lts of water, if a use for now on batch sparge, I just divide the sparge water in half for a 2 to run-offs?

about squeezing, I guess that enough gelatin and a good cold-crash should solve any clarity problem

any other problem so far? this thread is being very useful for me, thanks you guys

 

[brew703]

Well I heated the water to 167°F cuz once I pour all the grain, the water temperature descent, and at the end of the 90 min mash it should hit about the 152°F, please correct me if I'm wrong

About water calculation, here's what I use for a 5gallons batch, sorry but for this case, I gonna use metric system, don't know if could be an issue converting to imperial:

For a 20lts batch, I use 5kg grain bill. so:
5x3= 15lts, the grain absorb it's own weight in water, so 15-5= 10lts, so this is my strike water, about sparge, my losses add up to 3.35lts, in boil-off, contraction, trub loss and kettle loss, so my final volumen should be 23.35lts

therefore, for sparge it's 13.35lts of water, if a use for now on batch sparge, I just divide the sparge water in half for a 2 to run-offs?

about squeezing, I guess that enough gelatin and a good cold-crash should solve any clarity problem

any other problem so far? this thread is being very useful for me, thanks you guys

Looks like you are using a little over 6 gal total of water for a 5 gal batch with around 11+ lb of grain. That sounds about right. Water may be a little low but that would increase efficiency I believe.

Your strike temp is way high IMO. That will affect final gravity. It would make it high and unless you are brewing a stout you want a final gravity of 1.010 or in that area. Use https://pricelessbrewing.github.io/BiabCalc/#Advanced and try the calculator to determine strike water volume/temp.
Your temps will drop but you can always turn on the heat to bring it back up. Just make sure to continually stir so your bag doesn't burn.

 

[RM-MN]

Thanks for the feedback guys, you're right, more information could bring more insight about the issue

Here's my brewing schedule

1.- Milling, I mill the grain on my own with a corona grain mill, I hear about people having issues with this type of miller, for me, it works fine, this monday gonna upload a pic of the grist, cuz the miller it's borrowed, maybe a double milling could solve the problem, but kind concern about the stability of the grain bed for sparging

2.-Mashing, Single infusion, I heat the water at 167°F, insert the bag, pour the grain little by little while stir, and leave it for 90 minutes, I'm guessing the drop of temperature during the 90min mashing could be the main problem, cuz I just leave it there, I don't turn on the heater again for avoiding scorching the bag, also no mash out, I use German grain of the brand Bestzmalt, supposedly they are well-suited and enough modified for single infusion, right?

3.- Recirculation, just the typical thing, grab a bucket of wort and pour it through a skimmer for avoiding perforations in the grain bed, nothing fancy

4.- Sparge, I do fly sparging, for my batch of 4.7 gallons it takes me about 10 minutes, that is the maximum volume that I can work with my 5 gallons kettle, I just pour water at 158°F, again, through the skimmer for avoiding perforations, at the same rate of runoff

5.-Lifting the bag, I just lift the bag I discard the grain, no squeezing or draining whatsoever, about the draining, this last amount of wort drained of the bag wouldn't be all cloudy and charge of trub? Won't it affect the clarity of the final beer?

I don't use a mash tun, just collect the all the wort in a big pot, wash the kettle and pour again the wort in the kettle and then boil, whirlpool, cooling and to the fermenter

I use tasteless gelatin instead of Irish moss or whirlfloc tablet, those two are pretty hard to find and expensive here in Perú, but so far with a good cold-crash haven't had haze problems so far

Well, hope this could help to find the flat of efficiency of my process, thanks guys

1. Since this is a borrowed mill, you may be reluctant to change the setting but with a single pass through the mill it is impossible to mill too fine. I have mine set as tight as it goes.

2. With that high of strike temp, you may be denatureing the enzymes before they have time to finish their job. The initial temperature of the mash is what is important because much of the conversion will be done in the first 10 minutes.

3. Skip recirculating. It isn't needed.

4. Sparging should gain you some efficiency. I see a gain of 5 to 10%. There is little to gain from a fly sparge in this case. A dunk sparge will get you nearly the same with a lot less messing around.

5. Let the bag drain before sparging to get out as much of the sweet wort, squeezing will make this faster. Let it drain again after sparging to get more sweet wort again.

 

[soccerdad]

A couple of thoughts from me - some of which echo what others have said.

Your grist may be ok using a Corona mill, but post that pic.
167 seems hot to me - you want the mash at 152 (ish) as soon as possible. 160 might be better, even 158. I dough in around 156.

If you are sparging, divide your total volume of water into 2/3 (for mash) and 1//3 (for sparge). The sparge can just be in a food grade bucket .. lift the bag, let it drain enough to avoid slopping wort all over and drop it in the bucket. The temp of the water in the bucket is not important. Warm is better than too hot.

A large colander (again, no wort slopping over) that fits the bucket helps .. after sparge and stir, let the bag drain from the colander.

Add that wort back to the original wort.

If no colander, just gerry rig a way to hang the bag. Squeeze if you like - as you see here, many folks do so. Squeezing will not yield tannins.

Brew strong !

 

[Morrey]

Even with a Corona Mill, it is difficult to make your grist too fine for BIAB. I use an MM3 and when I thought I may be getting TOO fine, actually I wasn't and my efficiency peaked.

Always as a starting point when discussing BIAB efficiency, many of your experienced brewers will start with, "how fine is your grind"?

There are other variables for sure as being discussed here, and if you start with grind, chances are you'll see immediate improvements.

 

[Kee]

2.-Mashing, Single infusion, I heat the water at 167°F, insert the bag, pour the grain little by little while stir, and leave it for 90 minutes, I'm guessing the drop of temperature during the 90min mashing could be the main problem, cuz I just leave it there, I don't turn on the heater again

You have to hold your mash temperature in a range (usually between 148-157 degrees F, give or take a couple of degrees) for 30 minutes to one hour ideally.

Take a temperature reading after stirring in the grains, and take another one 30 minutes later. If you start in range and drop out that quickly, you need to be heating the wort or using insulation.

As others have noted, the finer the crush the quicker the conversion.

 

[cubalz]

Double crush the grain and squeeze that bag like it owes you money. This will get your efficiency back.

 

[CaptainCookie]

Sorry for the delay, had to do some deliveries, here's the grist after once a double milled, I'm pretty concerned about the grain bed stability in the double milled

I tried a little experiment with the double milled. I read about the grain potential a while ago in this article of BYO (https://byo.com/bock/item/1544-understanding-malt-spec-sheets-advanced-brewing) so I tried mashing half a pound of the double milled grain in a half gallon water (PPG but at half for save some grain, should have the same result, right?)

My malt has an Extract fine grind, dry basis of 80.5%, so...
Extract Potential = 1+0.805* 0.04621 = 1037

So, mashing one pound of my malt in a gallon of water should hit 1037 gravity, right?

after the little mashing that I perform with the double milled grain, just get 1037 gravity, so, this is the answer to the problem?

also, a just got a doubt, I have a kettle loss of about 0.22 gallons, as I perform sparge in the same kettle (don't have a mash tun just mash and sparge in the same kettle) after sparging I have this 0.22 gallons in the dead space of the kettle that I discard, using this volume won't defy the meaning of the recirculation? I mean this last wort is supposedly charged with flour of the grain and other residuals, won't this just add haze to the beer?

This question is because I just tried a little 1.85 gallon batch, with my water calculation of: (Sorry but again metric system)

2.5Kg grain bill
2.5X3=7.5 - 2.5 grain absorption = 5lts strike water
Batch size 7lts+ 3.35lts of losses = 10.35lts pre-boil (2.73gal)
Sparge water = 5.35lts

But after the sparge I got 8.5lts (2.24gal), so I guess the loss in water is due to 0.22gal after sparge that I discard plus not draining plus no squeezing

I don't make any of the procedures above to avoid any cause of haze or turbidity in the final beer

Thanks for the patience guys

 

[soccerdad]

My biab crush (using a Corona Style mill) is finer still than the double crush in the picture. I tend to get 75% + conversion in 40 minutes. More if I let the mash go longer. Just fyi.

 

[pricelessbrewing]

My biab crush (using a Corona Style mill) is finer still than the double crush in the picture. I tend to get 75% + conversion in 40 minutes. More if I let the mash go longer. Just fyi.

Sounds like you're getting conversion and mash efficiency mixed up. You should be hitting 90-95% conversion, unless you have significant pH issues, and 70-80% mash.

 

[soccerdad]

You're right. I project 75% efficiency when entering recipes in a calculator. I generally hit that in 40 minutes .. the pre-boil target.

 

[doug293cz]

...

I tried a little experiment with the double milled. I read about the grain potential a while ago in this article of BYO (https://byo.com/bock/item/1544-understanding-malt-spec-sheets-advanced-brewing) so I tried mashing half a pound of the double milled grain in a half gallon water (PPG but at half for save some grain, should have the same result, right?)

My malt has an Extract fine grind, dry basis of 80.5%, so...
Extract Potential = 1+0.805* 0.04621 = 1037

So, mashing one pound of my malt in a gallon of water should hit 1037 gravity, right?

after the little mashing that I perform with the double milled grain, just get 1037 gravity, so, this is the answer to the problem?

Not exactly. Most brewers don't correctly understand the definition of "points per pound per gallon" (including BrewersFriend in one of the places they do conversion efficiency calculations.) The definition is not based on water volume, but rather is based on wort volume. So that if you had one pound of grain with a potential of XX ppg, got 100'% mash efficiency, and collected one gallon of wort, you would have an SG of 1.0XX. But that one gallon of wort contains less than one gallon of water, with the balance of the volume made up of the extract from the grain. If you use one gallon of water to mash one pound of grain with a potential of XX ppg, and get 100% conversion efficiency, your wort SG will be less than 1.0XX because you will have created more than one gallon of wort. (But you couldn't actually recover all of the wort that you created because some will be retained due to grain absorption.)

Another small error comes from starting with dry extract potential, and not accounting for the typical 4% moisture content. This error is also made in both BrewersFriend and BeerSmith (unless they have been fixed since I last checked.) If your grain has a fine grind dry potential extract of 80%, then one pound of dry grain can create a max of 0.80 lb of soluble extract. However, if your grain has a moisture content of 4% (a typical value), then one lb of "as-is" grain contains only 0.96 lb of dry grain, as well as 0.04 lb of water. Thus your one lb of as-is grain only contains a max potential extract weight of 0.8 * 0.96 = 0.77 lb. If you mash one lb with one gallon of water (8.33 lb), and get 100% conversion, you will have 0.77 lb of extract, and 8.33 + 0.04 = 8.37 lb of water. This wort will have an SG in Plato of 100 * 0.77 / (0.77 + 8.37) = 8.42°P . If we convert 8.42°P to SG notation we come up with 1.0335, which is less than the 1.037 expected when using the incorrect definition.

So, I find points per pound per gallon more confusing than it's worth to most brewers. An easier way to use grain potentials is to think in terms of just points per pound. Then when dealing with wort, you think of points per gallon. To determine mash efficiency, you just divide collected wort points by total potential grain points. Collected wort points is just gallons of collected wort times the wort points per gallon. Total potential grain points is just average grain potential per pound times pounds of grain. For brewhouse efficiency, you just use the volume of wort to the fermenter rather than the volume of wort to the BK.

also, a just got a doubt, I have a kettle loss of about 0.22 gallons, as I perform sparge in the same kettle (don't have a mash tun just mash and sparge in the same kettle) after sparging I have this 0.22 gallons in the dead space of the kettle that I discard, using this volume won't defy the meaning of the recirculation? I mean this last wort is supposedly charged with flour of the grain and other residuals, won't this just add haze to the beer?

This question is because I just tried a little 1.85 gallon batch, with my water calculation of: (Sorry but again metric system)

2.5Kg grain bill
2.5X3=7.5 - 2.5 grain absorption = 5lts strike water
Batch size 7lts+ 3.35lts of losses = 10.35lts pre-boil (2.73gal)
Sparge water = 5.35lts

But after the sparge I got 8.5lts (2.24gal), so I guess the loss in water is due to 0.22gal after sparge that I discard plus not draining plus no squeezing

I don't make any of the procedures above to avoid any cause of haze or turbidity in the final beer

Thanks for the patience guys

I don't understand your strike water volume calculation. Can you explain what you are doing there (I do understand you're using 1 L/kg as a grain absorption rate, so you don't have to explain that)? The strike water volume calculation involving grain absorption with which I am familiar is:

Strike Volume = Target First Runnings Vol + Expected Grain Absorption + MLT Undrainable Vol​

And then Sparge volume is given by:

Sparge Volume = Target Pre-Boil Vol - Target First Runnings Vol​

I also don't understand why you are discarding any wort after sparging. Can you explain that in more detail?

Brew on

 

[Vandulus]

I just started BIAB a few batches ago and have been getting around 70-75% efficiency using my mill at a .39 mil gap. I'm wondering if maybe the water pH is too high or low and that may be affecting the efficiency? I'm slowly working up to playing around with adjusting my water, but it's low on the list since the report shows it's pretty good overall. One thing I do use is Five Star's pH 5.2 Stabilizer so I don't need to worry about pH levels as much.

 

[soccerdad]

I hate to be the 'well, actually' guy, but 5.2 has been shown to be a joke. If your ph is 5.2 it will help keep it at 5.2 (as I understand it), but if you are at 6.7 it will NOT magically adjust it to 5.2

 

[CaptainCookie]

I don't understand your strike water volume calculation. Can you explain what you are doing there (I do understand you're using 1 L/kg as a grain absorption rate, so you don't have to explain that)? The strike water volume calculation involving grain absorption with which I am familiar is:

Strike Volume = Target First Runnings Vol + Expected Grain Absorption + MLT Undrainable Vol​

And then Sparge volume is given by:

Sparge Volume = Target Pre-Boil Vol - Target First Runnings Vol​

I also don't understand why you are discarding any wort after sparging. Can you explain that in more detail?

Sure thing, for strike water calculation we use a factor called Filling Ratio, that is just how much water do you use per Kg of grain, the ratio is 3:1, this ratio is just for having a good amount of water soaking the grain, that's why:

2.5Kg*3= 7.5lts - grain absorption (2.5Kg) = 5lts strike water
you MLT Undrainable Vol will be my kettle dead space, a thing that I haven't considered so far, how do you calculate your Target First Runnings Vol?

I discard the wort after sparging and don't do any drainage, cuz I brew with a pal, and he freaks out about clarity and always said that left over after sparge is concentrate with flour of grain and proteins and stuff that will just cause haze in the beer, his logic is, we do recirculation for clarifying the wort, so what will be the point of clarifying the wort is you just drop all that stuff that is sedimented in the dead space of the kettle at the end of sparge? the same goes for draining, we lift the bag after sparge, all the wort that drain of the bag wasn't recirculated, ergo, not clarified, ergo, it will just add turbidity, any insight about this mess?

Another small error comes from starting with dry extract potential, and not accounting for the typical 4% moisture content.

so for my malt, technically the ppg it's 10335 with a 4% moisture content, thanks a lot, I'm pretty interested in the PPG calculation and efficiency, but as you said, this calculation is based on the wort volume instead of water, I didn't quite catch up this part:

So that if you had one pound of grain with a potential of XX ppg, got 100'% mash efficiency, and collected one gallon of wort, you would have an SG of 1.0XX. But that one gallon of wort contains less than one gallon of water, with the balance of the volume made up of the extract from the grain. If you use one gallon of water to mash one pound of grain with a potential of XX ppg, and get 100% conversion efficiency, your wort SG will be less than 1.0XX because you will have created more than one gallon of wort. (But you couldn't actually recover all of the wort that you created because some will be retained due to grain absorption.)

so my grain potential it's 10335, with a 100% mash conversion and collecting 1 gallon of wort I should get 10335 gravity, but it practice It's gonna be less, cuz we don't collect 100% wort, obviously, there's water in the mix too, I'm right?, also there's wort retain in the grain due to absorption, so the final gravity at the end of mashing theoretically should be less than 10335? again pretty interest in this topic

:rockin:

 

[filthyastronaut]

After looking at your crush, I'd take a look at your pH. If you can get information on your city's water and adjust accordingly with a water profile calculator, you don't really need a meter or anything. The ballpark works just fine.

 

[doug293cz]

Sure thing, for strike water calculation we use a factor called Filling Ratio, that is just how much water do you use per Kg of grain, the ratio is 3:1, this ratio is just for having a good amount of water soaking the grain, that's why:

2.5Kg*3= 7.5lts - grain absorption (2.5Kg) = 5lts strike water
you MLT Undrainable Vol will be my kettle dead space, a thing that I haven't considered so far, how do you calculate your Target First Runnings Vol?

What you call "Filling Ratio" is normally referred to as "Mash Thickness" on HBT. A typical mash thickness for fly sparging is 1.25 qt/lb or 2.6 L/kg. The way your strike water equation is written, you always use 2.0 L/kg (0.96 qt/lb), which should result in a very thick mash. Doesn't seem like you would have "a good amount of water soaking the grain." My original question could be restated as: "Why are you subtracting the grain absorption from the strike water volume?"

For batch sparging, it has been shown that you get the highest lauter efficiency when each of the runnings has equal volume. So, the goal is to calculate the amount of strike water and sparge water that will give you equal volumes for first runnings and sparge runnings. Since when you sparge, the grain has already absorbed as much as it is going to, you account for grain absorption in the strike water, and ignore absorption for the sparge. The math looks like this:

Target Runnings Vol = Target Pre-Boil Vol / 2 -- this is the tgt for both first and sparge runnings
Sparge Volume = Target Runnings Vol
Strike Volume = Target Runnings Vol + Expected Grain Absorption + MLT Undrained Vol​

So, for batch sparging you shouldn't be targeting a specific mash thickness or filling ratio. This can be a benefit because it has been shown that using a higher water to grain ratio in the mash speeds up the conversion process, which can in many cases improve your conversion efficiency. And, since your ratio is quite low, this might be part of your efficiency issue.

I discard the wort after sparging and don't do any drainage, cuz I brew with a pal, and he freaks out about clarity and always said that left over after sparge is concentrate with flour of grain and proteins and stuff that will just cause haze in the beer, his logic is, we do recirculation for clarifying the wort, so what will be the point of clarifying the wort is you just drop all that stuff that is sedimented in the dead space of the kettle at the end of sparge? the same goes for draining, we lift the bag after sparge, all the wort that drain of the bag wasn't recirculated, ergo, not clarified, ergo, it will just add turbidity, any insight about this mess?

Discarding wort after sparging makes no sense for any of the BIAB brewing process flows with which I am familiar. If you are really discarding your sparged wort, as you make it sound, that would really ruin your efficiency. Also, if you are just going to discard the sparged wort, why sparge in the first place. So, I guess I don't really understand the details of your brewing process. Can you provide a detailed step-by-step description of everything you do, starting with putting the strike water in the kettle, and continuing until you reach a boil?

Also, you don't need clear wort to make clear beer, and clear wort may not even make clear beer always. I squeeze the bag and have very cloudy wort, but make crystal clear beers. Most of the particulates drop out during fermentation and cold crashing. I also use gelatin as a fining agent when I keg.

so for my malt, technically the ppg it's 10335 with a 4% moisture content, thanks a lot, I'm pretty interested in the PPG calculation and efficiency, but as you said, this calculation is based on the wort volume instead of water, I didn't quite catch up this part:


so my grain potential it's 10335, with a 100% mash conversion and collecting 1 gallon of wort I should get 10335 gravity, but it practice It's gonna be less, cuz we don't collect 100% wort, obviously, there's water in the mix too, I'm right?, also there's wort retain in the grain due to absorption, so the final gravity at the end of mashing theoretically should be less than 10335? again pretty interest in this topic

:rockin:

No, your dry basis grain potential really is 1.037 (calculated as 0.805 * 46.2 = 37.2 ==> 1.037.) The as-is (with moisture) potential would be 0.805 * 0.96 * 46.2 = 35.7 points/lb or 1.036 expressed as SG potential. The 46.2 is the pts/lb of sucrose, which has 100% extract potential.

The reason we ended up with only 1.0335 SG in the calculation example is that we created more than 1 gal of wort from the 1 gal of strike water. We actually had:

(0.77 lbs + 8.37 lbs) / (1.0335 * 8.33 lb/gal) = 1.06 gal of wort, and
1.06 gal * 33.5 pts/gal = 35.6 pts​

which is within rounding error of the expected 35.7 pts for the as-is grain potential.

You are correct that we would not be able to get all of the 1.06 gal of wort separated from the grain due to the grain absorption. Grain absorption is the primary determinant of lauter efficiency, which measures how well you separate the sugar from the grain. Mash efficiency is equal to conversion efficiency times lauter efficiency. You can get 100% conversion efficiency (90% - 95% is more common), but you can never get 100% lauter efficiency because you can never get all of the wort (and thus sugar) out of the grain.

However, the grain absorption does not affect the gravity of the collected wort. The wort you drain, and the wort absorbed by the grain, have the same SG.

Brew on

 

[CaptainCookie]

What you call "Filling Ratio" is normally referred to as "Mash Thickness" on HBT. A typical mash thickness for fly sparging is 1.25 qt/lb or 2.6 L/kg. The way your strike water equation is written, you always use 2.0 L/kg (0.96 qt/lb), which should result in a very thick mash. Doesn't seem like you would have "a good amount of water soaking the grain." My original question could be restated as: "Why are you subtracting the grain absorption from the strike water volume?"

Well I just come to realize how redundant it's, that's the way we were told to make the calculation, but is just straightforward as multiplicate the mash thickness, feeling dumb right now

So, for batch sparging you shouldn't be targeting a specific mash thickness or filling ratio. This can be a benefit because it has been shown that using a higher water to grain ratio in the mash speeds up the conversion process, which can in many cases improve your conversion efficiency. And, since your ratio is quite low, this might be part of your efficiency issue.

I've read about it in an article in BYO, yes, gonna try this calculation with batch sparge, we were doing fly sparge, again, cuz that's the way that we were told, but, what kind of equipment will be mandatory to make a fly sparge? gonna try batch sparge, but I just want to know anyway

Discarding wort after sparging makes no sense for any of the BIAB brewing process flows with which I am familiar. If you are really discarding your sparged wort, as you make it sound, that would really ruin your efficiency. Also, if you are just going to discard the sparged wort, why sparge in the first place. So, I guess I don't really understand the details of your brewing process. Can you provide a detailed step-by-step description of everything you do, starting with putting the strike water in the kettle, and continuing until you reach a boil?

We don't discard the sparge water, that would make all pointless, let me explain myself better as you ask

we only have a 5.3gallon (20lts) kettle, so we do the mashig, recirculation, sparge, and boiling in the same kettle, this kettle has a dead space (space between the bottom and the collection pipe) of aprox 0.21gal (0.8L) that would be our kettle trub loss

Well in detail our process after mashing is (already detail mashing in a previous post):

after the mash, we begin recirculation, we grab a sanitized bucket, open the pipe, and begin to collect some wort, then pour the collected wort back into the kettle through a skimmer for avoiding perforations in the grain bed, we repeat the process until we got a good clarified wort

then we begin to sparge, we grab a big sanitized pot (about 30lts), open the pipe, and begin to collect all the wort, at the same time we add the sparge water at 158°F into the kettle at the same rate of the run-off, again through the skimmer, after we collect all the wort, we lift the bag and there's a remaining volume of wort in the dead space of the kettle, this is the wort we discard, why we discard this? as I said before, my pal always say that the purpose of recirculation is to clarify the wort, so he believes that all this stuff that makes the wort cloudy is decanted in the dead space of the kettle, and using this left behind concentrated wort would cause haze in the beer, cuz, what would be the point of clarifying the wort in the recirculation if we pour all the cloudy stuff back into the kettle? the same with draining the bag, as we lift the bag at the end of the sparge, the drained wort of the bag wasn't recirculated, so we discarded it, so again the question, is all this right? or is just as simple as using the 100% of the wort (dead space trapped wort, drained wort from bag, squeezing the bag) and just eliminate recirculation, as it will be pointless? as you said before, cloudy wort doesn't necessarily mean cloudy beer

No, your dry basis grain potential really is 1.037 (calculated as 0.805 * 46.2 = 37.2 ==> 1.037.) The as-is (with moisture) potential would be 0.805 * 0.96 * 46.2 = 35.7 points/lb or 1.036 expressed as SG potential. The 46.2 is the pts/lb of sucrose, which has 100% extract potential.

The reason we ended up with only 1.0335 SG in the calculation example is that we created more than 1 gal of wort from the 1 gal of strike water. We actually had:

(0.77 lbs + 8.37 lbs) / (1.0335 * 8.33 lb/gal) = 1.06 gal of wort, and
1.06 gal * 33.5 pts/gal = 35.6 pts​

which is within rounding error of the expected 35.7 pts for the as-is grain potential.

again, as you said before, this isn't a reliable way to calculate the efficiency? in simple terms, mashing a pound of malt in a gallon of water won't give me the answer?

 

[doug293cz]

Well I just come to realize how redundant it's, that's the way we were told to make the calculation, but is just straightforward as multiplicate the mash thickness, feeling dumb right now



I've read about it in an article in BYO, yes, gonna try this calculation with batch sparge, we were doing fly sparge, again, cuz that's the way that we were told, but, what kind of equipment will be mandatory to make a fly sparge? gonna try batch sparge, but I just want to know anyway



We don't discard the sparge water, that would make all pointless, let me explain myself better as you ask

we only have a 5.3gallon (20lts) kettle, so we do the mashig, recirculation, sparge, and boiling in the same kettle, this kettle has a dead space (space between the bottom and the collection pipe) of aprox 0.21gal (0.8L) that would be our kettle trub loss

Well in detail our process after mashing is (already detail mashing in a previous post):

after the mash, we begin recirculation, we grab a sanitized bucket, open the pipe, and begin to collect some wort, then pour the collected wort back into the kettle through a skimmer for avoiding perforations in the grain bed, we repeat the process until we got a good clarified wort

then we begin to sparge, we grab a big sanitized pot (about 30lts), open the pipe, and begin to collect all the wort, at the same time we add the sparge water at 158°F into the kettle at the same rate of the run-off, again through the skimmer, after we collect all the wort, we lift the bag and there's a remaining volume of wort in the dead space of the kettle, this is the wort we discard, why we discard this? as I said before, my pal always say that the purpose of recirculation is to clarify the wort, so he believes that all this stuff that makes the wort cloudy is decanted in the dead space of the kettle, and using this left behind concentrated wort would cause haze in the beer, cuz, what would be the point of clarifying the wort in the recirculation if we pour all the cloudy stuff back into the kettle? the same with draining the bag, as we lift the bag at the end of the sparge, the drained wort of the bag wasn't recirculated, so we discarded it, so again the question, is all this right? or is just as simple as using the 100% of the wort (dead space trapped wort, drained wort from bag, squeezing the bag) and just eliminate recirculation, as it will be pointless? as you said before, cloudy wort doesn't necessarily mean cloudy beer



again, as you said before, this isn't a reliable way to calculate the efficiency? in simple terms, mashing a pound of malt in a gallon of water won't give me the answer?

Thanks, I think I have a good understanding of your process now. It is really just a variation on a traditional 3 vessel process, except that a single vessel is used for both MLT and BK. In this case your 0.8 L of undrainable volume affects both the mash losses and the BK to fermenter losses.

I did some single, double, and triple batch sparge simulations for your grain bill, and pre-boil volume, using both your 0.8 L undrainable and also 0 undrainable volumes. With your system plus undrainable, the single batch sparge gives 76.4% lauter efficiency, double is 79.7%, and triple is 81.2%. I can't simulate fly sparging (the dynamics and variables are way too complex) but a fly sparge is basically equivalent to a very large number of very small sparges. As you can see each additional batch sparge step gives less and less improvement, thus with a perfectly done fly spage you would be hard pressed to do better than about 83% efficiency. If you eliminated your undrainable volume the corresponding lauter efficiencies would be 78.8%, 82.0%, and 83.4%. A perfect fly sparge in the 0 undrainable case could give you about 85%.

I did some strike temp calcs with your grain bill and low strike water volume, and your 167°F strike temp is not out of line. You shouldn't be doing any significant damage to your enzymes due to your strike temp.

I believe a big part of your efficiency problem is because of your sparge process, and drain configuration on your vessel. For a good fly sparge, you want to start with 1 - 2" of wort above the grain bed, and maintain that until you have added all of your sparge water. Given your very low filling ratio (mash thickness) I'm not sure you will have an adequate amount of wort above the grain bed. If this is the case, then you are likely to get channeling, even though you try to distribute the sparge water across the surface of the mash.

Another issue with your sparge process is its speed. You should try to extend your sparge time to 30 minutes to minimize channeling. This is especially true since you have a side pickup in your vessel with no false bottom. This encourages a flow pattern thru the grain bed that wants to bypass the lower part of the bed that is away from the pickup.

For your equipment configuration, I think you would get much better results by batch sparging. The basic steps are:

• Stir mash well at the end of the mash time
• Vorlauf (recirculate) if you want, but it's not really necessary when using a bag
• Completely drain all of the wort, as fast as your system will allow without sticking the lauter
• Add your sparge water and stir well for about 5 minutes
• Vorlauf (recirculate) if you want
• Completely drain all of the wort, as fast as your system will allow
• Start the boil (with a separate MLT and BK, heating to a boil can start after the first runoff)

Remember that:

Mash Efficiency = Conversion Efficiency * Lauter Efficiency​

And all of the above discussion is only about lauter efficiency.

The conversion efficiency in your mash can be measured in real time using the method described here. Anything better than 90% is OK, better than 95% is good, and above 98% is great.

There are a number of on-line calculators that will do a good job of calculating your mash efficiency grain bill, pre-boil SG, and pre-boil volume, or from your grain bill, post-boil SG (i.e. OG), and post-boil volume. (If you want the details on doing the calculation using points, just ask.) Once you have your mash and conversion efficiencies, you can calculate your lauter efficiency as:

Lauter Efficiency = Mash Efficiency / Conversion Efficiency​

Brew on

 

[CaptainCookie]

Thanks, I think I have a good understanding of your process now. It is really just a variation on a traditional 3 vessel process, except that a single vessel is used for both MLT and BK. In this case your 0.8 L of undrainable volume affects both the mash losses and the BK to fermenter losses.

I did some single, double, and triple batch sparge simulations for your grain bill, and pre-boil volume, using both your 0.8 L undrainable and also 0 undrainable volumes. With your system plus undrainable, the single batch sparge gives 76.4% lauter efficiency, double is 79.7%, and triple is 81.2%. I can't simulate fly sparging (the dynamics and variables are way too complex) but a fly sparge is basically equivalent to a very large number of very small sparges. As you can see each additional batch sparge step gives less and less improvement, thus with a perfectly done fly spage you would be hard pressed to do better than about 83% efficiency. If you eliminated your undrainable volume the corresponding lauter efficiencies would be 78.8%, 82.0%, and 83.4%. A perfect fly sparge in the 0 undrainable case could give you about 85%.

Sweet thanks, could you please share the simulation's math? I'm pretty fond of the beer's maths, also how can I make up for a triple batch?

I'm currently working with 2 batches, a 17lts batch for my normal beer, a red ale, and 7lts for my experiments with new varieties, sorry for using metric system, but I'm more used to it

For the 17lts batch, my target pre-boil is 20lts, the capacity of my kettle, accounting:
-1lt kettle loss
-1lt boil-off
-1lt fermenter loss
but now, I should account 0.8lts sparge loss plus 0.5lts drainage loss (in the case of discarding the dead space after sparge and no performing a bag drainage), I'm right? gonna try to convince my pal to make use of this wasted wort

anyway just accounting with the 20lts pre-boil (5Kg grain bill), for the batch sparge will be:

Tgt vol: 20/2= 10lts
Sparge vol: 10lts
Strike vol: 10+5+0.8= 15.8lts
this calculation will be with only one sparge (10lts), but if I wanna do a double batch, I just pour another 10lts? the same for a third batch? the same goes for a 7lts batch (10lts pre-boil)?

There are a number of on-line calculators that will do a good job of calculating your mash efficiency grain bill, pre-boil SG, and pre-boil volume, or from your grain bill, post-boil SG (i.e. OG), and post-boil volume. (If you want the details on doing the calculation using points, just ask.)

Please, I hate being a pain in the ass, but please I would love to have the detailed calculation using points, I think that just using online calculator is just no fun

 

[doug293cz]

Sweet thanks, could you please share the simulation's math? I'm pretty fond of the beer's maths, also how can I make up for a triple batch?

I have previously posted a description of the simulation here.

Beer club tonight. I'll try to respond to your other questions/requests on Saturday.

Brew on