Please Help an old hand understand BIAB

[lazarwolf]

Ok, So I have been brewing since the dawn of time. Well maybe not that long, but since the 1st Bush Administration. When I started brewing you pretty much had 2 choices, extract or all grain. When I started brewing we had to do step mash. The grains weren't "well modified". The only way to get unhopped extract was to buy Blue Ribbon Malt Syrup at the grocery store, or Blue Ribbon Malt Flour "a baking additive" (yeah right no one was using that for back porch brewin or moonshining.)

And then these crazy guys came up with partial mash. Partial is my every day, go to brewing technique. But I also enjoy doing small batch All grain. By small batch I mean, as much as I can handle in my stove top equipment, never less than 2.5 gallons, usually around 4.4 gallons. Of course when I do all grain, I want a full volume boil, complete conversion of my mash, etc... I have the all grain equipment. I have quite a little set up actually, all kinds of ghetto gear gets employed.

But im intrigued by the biab thing. If I already own my "ghetto grain" system, why would I want to try BIAB.? I must admit the single pot is attractive. The greatly lowered efficiency is not...

So help me out. How do you account for the lower efficiency? More grain? And if you're not sparging, how are you getting good yield. Or are we back to the idea that efficiency just doesn't really matter.

 

[jtratcliff]

Greatly lowered efficiency is a myth. Since the bag eliminates stuck sparges you can grind the hell out the grain. I routinely get mid 80s with a dunk sparge in a separate pot.

 

[btbnl]

Easy 80% with no sparge here, double-milling the grains at the LHBS.

 

[jtratcliff]

I have a 10 g pot and manage to do 6.5 gal stovetop batches.

12-13 lbs of grain, super fine crush from my corona mill, 6.5 gallon mash-in, 1.5 gallon dunk sparge, squeeze the bag like it owes you money (tannins from squeezing are a myth), routinely in the 80s for efficiency.

Get yourself a 5g paint strainer bag for a couple of bucks and give it try. The crush is key, though. Gotta be fine. Almost flour. More important than no sparge vs dunk sparge vs pour over sparge or even hot sparge vs cold sparge.

 

[lazarwolf]

so one vote for dunk sparge, one vote for no sparge. Hmmm. @btbnl, do you squeeze your bag?

@itratcliff how do you calculate your dunk sparge water volume? standard all grain sparge volumes? 1.3qt/lb and 1.3qt/lb?. Do you get into mash thickness calculations?

 

[btbnl]

I don't squeeze - just hoist and drip.

I do dunk-sparge my 10G batches because I can't fit all the water and the grain into a 15G keggle, so I mash in 11G and dunk sparge in the other ~4G.

Typically I'll do a 10G and 5G batch in the same brew day, and heat the 10G's sparge water along with the mash water for the 5G batch.

 

[NeoBrew]

You only need to consider mash thickness if you are doing a two part process, i.e. dunk sparging or pour over sparge. And then it's only to make sure you don't lower your efficiency too much with a thick mash.

The grain absorption is the same as 3 vessel brewing. I use Beersmith for all my calculations and it does a great job without changing any of the ratios for BIAB.

 

[FatDragon]

Yeah, I break 80% consistently doing BIAB with an 8 liter cold water pourover sparge in a separate bucket and squeezing the bag. I even got 82% on a high-gravity RIS that barely fit in the kettle.

If you're comfortable brewing with your current setup, by all means keep doing it. If you aren't really loving it and think a change to BIAB might improve things, give it a try. A fine crush, proper mash-in (dump all the grain at once and get it all mixed in without any doughballs), and good drain and squeeze should get you the efficiency you desire, though it might take a couple attempts to really get the techniques down.

As for calculating sparge water, I calculate the water for a full-volume mash and take my sparge water from there. Not that you were asking me specifically.

 

[lazarwolf]

so, i have some large pots and some bags. maybe, its time to give this a try.

 

[lazarwolf]

@fatdragon, you say full volume mash... as an all grain/partial mash guy, to me that means about 1.75-2 guarts per lbs? but i know biab calculators are telling me numbers around 5g for a 4.4 yield...can you guys elaborate more

 

[soccerdad]

In my experience there is no reduced efficiency ( pretty much always over 75% and often over 80) and really no need for the fine crush if you are ok with a longer mash. The fine crush seems to speed up the conversion for many people.

The original Aussie experiments were full volume mash - all the water for the whole brew in one kettle with all the grain. So if you wanted a 5 gallon batch, and you boiled off 2 gallons in an hour and you lost a half gallon to trub and absorption, then you started with 7.5 gallons plus you needed room for maybe 15 pounds of grain. There is no need for a separate sparge step.

But some folks do not have a 10 gallon or larger kettle so dunk sparges and pour over sparges are employed. But the concept is the same .. gather all the grain you need and all the water you need and do it all ( or most all) in one vessel.

 

[lazarwolf]

In my experience there is no reduced efficiency ( pretty much always over 75% and often over 80) and really no need for the fine crush if you are ok with a longer mash. The fine crush seems to speed up the conversion for many people.

The original Aussie experiments were full volume mash - all the water for the whole brew in one kettle with all the grain. So if you wanted a 5 gallon batch, and you boiled off 2 gallons in an hour and you lost a half gallon to trub and absorption, then you started with 7.5 gallons plus you needed room for maybe 15 pounds of grain. There is no need for a separate sparge step.

But some folks do not have a 10 gallon or larger kettle so dunk sparges and pour over sparges are employed. But the concept is the same .. gather all the grain you need and all the water you need and do it all ( or most all) in one vessel.

the notion that i don't have to do a mash calc,is appealing. so i want 4.4 gallons, i need about 7 gallons so a 32qt pot wont do it? i would need to sparge.

 

[lazarwolf]

And I'm guessing water chemistry is an issue.

 

[soccerdad]

I don't think water is different from any other adjustment you would make for 3 vessel or PM. But I'm lucky with water and don't have to do much .. limited experience there.

I brew with an 8 gallon pot, so I often count down from 8 rather than up from 5 depending on how big the beer is that I am making. A lot of my 5 gallon batches come in at 4 & 3/4

 

[lazarwolf]

OK this is getting cool. I'm in. So ask for a finer crush. Count down from 8, my pot is also 8. Mash right there in the pot, pull the bag, a light rinse, rock and roll? And it actually works?

 

[FatDragon]

@fatdragon, you say full volume mash... as an all grain/partial mash guy, to me that means about 1.75-2 guarts per lbs? but i know biab calculators are telling me numbers around 5g for a 4.4 yield...can you guys elaborate more

I pay no attention to mash thickness (qt/lb or l/kg). I figure out what I want my final volume to be, then I figure out how much water I expect to lose in the process (trub, boiloff, water left in the grains), and that's my total water needed. Since I sparge, I subtract my sparge volume (usually 8 liters) from the total water volume, and that's my strike water volume.

For that reason, I don't follow Beersmith's BIAB profile for strike temperature (it calculates for a full volume mash, which means a greater thermal mass of the strike water, meaning my thicker mash is going to require a higher strike temp), but calculate it separately, although I'm working on tweaking a personalized "BIAB + Sparge" profile in Beersmith that will do that work for me.

If a BIAB calculator is telling you to use 5 gallons of water for a 4.4 gallon final volume, there are some incorrect variables being used. Maybe it's estimating pre-boil volume and only subtracting for grain absorbtion? You'll only get proper estimates for something like that if the variables fit your system and process - boil-off, trub loss, grain absorbtion - if the variables don't fit, you'll probably still get a decent ballpark figure, but not an exact number.

 

[wilserbrewer]

OK this is getting cool. I'm in. So ask for a finer crush. Count down from 8, my pot is also 8. Mash right there in the pot, pull the bag, a light rinse, rock and roll? And it actually works?

Your 8 gallon pot is right on the cusp of needing to do a sparge. You could mash in w/ 6 gallons and 10 lbs of grain to give a total mash volume of 6.8 gallons, let mash. At the end of the mash add in an additional gallon of water, hotter the better so as not to cool the mash and take longer to reach boil etc....
This results in maxing out your 8 gallon pot at 7.8 gallons. Stir well let rest a few minutes and pull the grain bag leaving you with about 7 gallons preboil. I like topping up the mash rather than trying to mash in at 7.8 gallons as it could get messy that close to the rim.

A sparge may gain a couple points. but sometimes its easier to not bother....up to you.

W/ a 5 gallon batch and an 8 gallon kettle, not much need for calcs IMHO, just max out the kettle and your there, w/ boil off you'll be right at 5.5 - 6 gallons...perfect and easy peasy.

 

[RM-MN]

OK this is getting cool. I'm in. So ask for a finer crush. Count down from 8, my pot is also 8. Mash right there in the pot, pull the bag, a light rinse, rock and roll? And it actually works?

Of course it doesn't work, it can'r. That's why so many of us are drinking grain tea.

The grain doesn't care what kind of vessel it gets for a mash nor do the enzymes. With BIAB you are just substituting the boil pot for the mash tun and the bag instead of a bazooka screen. The efficiency can be higher because the higher amount of water can dissolve more sugars (more dilution) and the bag makes such a good filter that can be removed with the grains inside for more complete wort collection. Also, since there is such a large filter area (the bag) we can get by with a finer milling of the grain. Those smaller grain particles allow more sugars to be extracted, raising the efficiency along with allowing a shorter mash time. I've been trying a 20 to 25 minute mash and getting full conversion and the same efficiency as I was with a 60 minute mash and have even tried a couple at 10 minutes. I'm not yet convinced that 10 minutes is sufficient but I intend to try another batch or 2 just to find out.

 

[brewguyver]

OK this is getting cool. I'm in. So ask for a finer crush. Count down from 8, my pot is also 8. Mash right there in the pot, pull the bag, a light rinse, rock and roll? And it actually works?

Why wouldn't it work? Conceptually there really isn't much difference between BIAB and the three vessel approach.

First you're heating water up in your "hot liquor tank" (your brew pot), and putting in a "false bottom" (strainer bag).

Next, you get that water in your "mash tun" (again, your brew pot which is now full of the right temp water so no additional action needed), and dough in. I usually put a foldable steamer in the bottom first so I can heat up the mash on low if I need/want to without risking melting the bag.

Once your mash is done you either sparge (in case you needed higher volume), or do no sparge, just like in a 3 vessel system. In this case you pull the grain bag out and run the water through, *or* if your pot has a ball valve you can run the wort off into a bucket, and batch sparge. Just add new water, bring it to mash out temps, and then pull the grain out so it drips the rest of the wort. Personally I don't sparge in BIAB - not worth the effort IMHO.

Lastly, you move the wort to your boil kettle (again, this is your same pot, so no/minimal effort) and do your boil.

So in summary, BIAB is just like traditional three vessel brewing. The difference is you're using a bag to move the grain instead of leaving the grain and moving the wort. All other considerations other than efficiency and labor, like water chemistry, remain the same.

If you have a place to hang it, I would suggest a pulley for the grain. It's not necessary, but it's significantly more convenient.

Finally, +10 to everyone's comments on Beersmith software. It costs about $20 on sale, does the hard calculations for you, and it's super helpful for recipe design. The software looks and feels like a windows 3.1 app, so it's pretty easy to navigate. It also comes with good tutorials if your less comfortable around computers.

 

[brewguyver]

Related, I'm not sure why people get better efficiency with BIAB, but they do. I sometimes get low efficiency in my outdoor 3 vessel setup (60's), and expected that when I did my first BIAB (was too damn cold out so I brewed in the kitchen). I think I hit 80% and accidentally made an 8% cream ale or something equally ridiculous.

I'm sure there is some science behind this, but I'll leave the explanation to an actual scientist.

 

[LLBeanJ]

For that reason, I don't follow Beersmith's BIAB profile for strike temperature (it calculates for a full volume mash, which means a greater thermal mass of the strike water, meaning my thicker mash is going to require a higher strike temp), but calculate it separately, although I'm working on tweaking a personalized "BIAB + Sparge" profile in Beersmith that will do that work for me.

BS actually handles this quite easily. While still utilizing the BIAB mash profile, just enter your sparge volume in the Kettle Top Off field on the Volumes tab and that amount will be subtracted from the mash volume, rendering an accurate strike volume and temp. Also, be sure to set your mash tun temp = to the calculated strike temp.

 

[lazarwolf]

I was always taught that too thin of a mash volume would hinder the conversion of starches. But obviously that's out dated wisdom. After 20+ years of being I'm finally reading some new beer books. I generally make fairly low gravity quad fable beers. So I think the pot will work fine for most of my beers.

 

[shetc]

Have a look at our friends over at http://www.biabrewer.info/ - I have had great success using the info I learned there.

 

[madscientist451]

Part of the original question I believe was why do BIAB?
The short answer is, no fussing with trickle sparging, its faster, no stuck sparges.
I was skeptical BIAB was going to work. If BIAB is so simple and easy, why were people doing the fussy and time consuming trickle sparge technique?
So I tried it and yeah it works great. I don't like BIAB in my kettle though because with the full boil volume and grains, my kettle is very close to spilling over. Then when I pulled the bag I always spilled wort on the stove. So I just got a round cooler, put a valve on it and put my BIAB in there and drain to the kettle. Pretty easy.
There have been side by side taste tests with BIAB and traditional method beer and the consensus is that you can't tell the difference.
I haven't run that kind of experiment yet, so I don't really know if thats true for all beers.

 

[Gavin C]

I certainly wouldn't let the poor efficiency myth guide your decision into utilizing BIAB.

My mash efficiencies are predictable at 85+% and my brewhouse efficiency is regulary 74-76%. The resulting OG and volume into the FV are usually within a point of the target OG.

Check out my process in my thread below. It really is a simple and fun way to do all-grain brewing.

 

[soccerdad]

I generally make fairly low gravity quad fable beers. So I think the pot will work fine for most of my beers.

I totally agree - and if, like the mad scientist, you don't like wrestling the bag out of the kettle - a 10 gallon cooler is a fantastic option .. although I was always told you have to wear a ten gallon hat with a 10G cooler and I don't have one

 

[lazarwolf]

Im designing a brew session for this weekend. My boil off rate is no where near 1.25 gallons per hour on my electric stove top. Closer to only .5 gallons per hour. So when I calculate, i should just use .5 for loss to boil off, right?

Here are the numbers
7.25 lbs of grain 65 F grain temp 153F mash temp
60m boil time
5 gallon batch
kettle size is 34 quarts or 8.5 gallons
trub 1 gallon
boil off .5 per hour on the ol stove top
grain absorption of .045 gallons / lbs

the calc says i need
6.83 gallons
157 degree strike water? sounds low
7.41 gallon total mash volume
6.5 preboil wort
6 post boil wort
5 gallons of yummy beer to fermenter.

sound right?

 

[soccerdad]

sounds right to me

I think I might do 7G in the kettle - to assure no spillage when adding grain - and have the .4G in a hot teakettle to slowly add in as space allows - what's .4? 50 ounces?

 

[McKnuckle]

Your strike water temp is lower than it would be for a non-BIAB mash because you're going full volume. More water = greater thermal mass = less heat required to equalize to the desired mash temperature.

About absorption rate - typically we see more like 0.32 qt/lb or 0.08 gal/lb and that's with no squeezing, just a nice long gravity drain.

 

[lazarwolf]

.45 gallons per pound of grain lost to absorption

 

[Gavin C]

I don't lose much to absorption because I squeeze. Generally I loose about 1/2 gallon for an 10-11 lb grain bill. All systems will be a little different. I find Beersmith to be spot on when it comes to volume calculations once the correct variables are entered.

A typical brew in my 10 gallon megapot (holds 11G) I think.

Approximate measures would be

7.5 gallons of strike water
10-12lbs grain
1.25g boil-off per hour on my NG stove
0.25 gallon lost to trub and plate chiller/pump tubing assembly

5.5g to FV

 

[doug293cz]

So in summary, BIAB is just like traditional three vessel brewing. The difference is you're using a bag to move the grain instead of leaving the grain and moving the wort.

Brilliant! I never thought of it that way, but it's a perfect way to describe the difference.

Brew on

 

[doug293cz]

.45 gallons per pound of grain lost to absorption

EDIT: noticed the 0.45 above was a typo compared to your previous post where you used 0.045.

Depending on how you handle bag draining, your grain absorption should be in the 0.05 to 0.125 gal/lb. 0.05 is for a very aggressive bag squeeze, and 0.125 for just a short drain. A long drain, with no squeeze, should put you in the 0.08 to 0.10 range. You'll have to make measurements with your process to get better estimates than that.

Brew on

 

[brewguyver]

I was always taught that too thin of a mash volume would hinder the conversion of starches. But obviously that's out dated wisdom. After 20+ years of being I'm finally reading some new beer books. I generally make fairly low gravity quad fable beers. So I think the pot will work fine for most of my beers.

Careful - in other styles of mashing, being too thin or thick can still be an issue. Most of this stuff around efficiency applies specifically to BIAB.

 

[doug293cz]

Careful - in other styles of mashing, being too thin or thick can still be an issue. Most of this stuff around efficiency applies specifically to BIAB.

What sort of issues?

Brew on

 

[Foosier]

I agree. I don't have efficiency issues. If I was to claim an issue it would be regularly over shooting my OG by a point or two.

I do full volume mash BIAB in my 10Gal pot outdoors. I do not sparge, I lift the bag when mashout is complete and set the bag in a bucket to continue draining. I have hit 80-85% on my last 4 brews. One of those included a triple that maxed out my pot. (overshooting that gravity made for a powerful triple!)

 

[BridgewaterBrewer]

Kai Troister (the Braukaiser) did some great experiments looking at the effects of many mash parameters (time, pH, mill gap spacing etc) on efficiency and showed that mash thickness is not critical at all.
http://braukaiser.com/documents/Effects_of_mash_parameters_on_attenuation_and_efficiency.pdf

 

[jtratcliff]

@itratcliff how do you calculate your dunk sparge water volume? standard all grain sparge volumes? 1.3qt/lb and 1.3qt/lb?. Do you get into mash thickness calculations?

I see that this is pretty much answered by others up thread but for completeness, I'll chime in...

I figure my total volume for a 6.5 gallon batch accounting for kettle losses, grain absorption and boil off, etc, then I decide the volume (grain + hot liquor) I'm comfortable mashing in my 10G kettle. Everything else goes in the sparge. I mostly do a dunk sparge because I'm a little nervous going all the way the top of my kettle trying for a no-sparge

Usually, it ends up being about 6.5-7 G of water to mash and 1.5 G to sparge in a 12-13 lb grain bill. But I'll juggle those volumes as needed to fit my available kettle sizes depending on the grain bill. I think it's usually somewhere in the 2.3 to 2.5 qt/lb range. I use brewtarget and it's mash wizard to calculate volumes and temps. There are plenty of BIAB calculators that you can use to get volumes and temps without going to a full-on brew software package.

It really is that easy.

 

[Magnus314]

Just get a true BIAB bag (I like my Wilserbrewer bag, might as well get the pulley and extras for like $10 extra or whatever) and try it.

Everything else is conjecture until you try it once and note your results!

You could have higher, or lower, mash efficiency. You might need more, or less water and have to, or not have to, pour over sparge, or a longer, or shorter, mash time.

BIAB is great. I think better (and I abandoned a many-hundreds-of-dollars-and-many-hours-of-labor 3 vessel system to go BIAB the first time).

None of the variables are for sure, until you know what you need to adjust for. Then, it's easy!

 

[lazarwolf]

Well I appreciate all the help. Like I said not new to brewing, but Just haven't tried the biab thing before. I do occasionally like to do an all grain batch. But my thinking has always been that BIAB should probably result in higher efficiency not lower, you have all confirmed my suspicions. Like all brewing it is really about the skill set, fresh ingredients, and attention to detail of the brewer, and not really just about which process you are using.