Help dialing in BIAB process?

[TripleC223]

I made the jump from extract to BIAB three batches ago and have had varying degrees of success each time. My efficiency has ranged from 45% to 65%, though my last batch was disappointingly on the low end of that spectrum.

That said, I'm hopeful I can get some pointers from you guys about how to improve my process going forward. I am still in the kitchen doing most of this on a stovetop.

*Note that this process is designed to yield 3 gallons of fermentable wort.

Water Prep

1. Pour four gallons of distilled water into my 5-gallon aluminum brew kettle.
2. Adjust profile of entire four gallons based on Bru'n water adjustments (gypsum & calcium chloride).
3. Remove two gallons of treated water from the brew kettle by refilling empty gallon jug. Pour those two gallons into a separate pot for sparge water to use later.

Mash

1. Insert paint strainer bag into brew kettle as water is heating. Loop elastic band around rim of brew kettle.
2. Preheat oven to 175.
3. Heat remaining ~2 gallons of water in brew kettle to appropriate temp (usually ~165 depending on what Can You Mash It recommends).
4. Pour pre-crushed grains (usually 5-7 pounds) into brew kettle/bag. Stir grains during pour to ensure adequate water contact.
5. Take temperature reading and say "close enough" if it's in 148-152 range (haven't missed this yet, thankfully).
6. Cover brew kettle and turn off preheated oven.
7. Place covered brew kettle (now a mash tun?) into preheated oven for 60-90 minutes.
8. Stir grains and take temp reading every 20 minutes.
9. Heat pot of ~2 gallons sparge water to 170 degrees.

Grain Removal/Sparge

1. After mash is complete, return brew kettle to stove.
2. Remove bag of grains from brew kettle and let drain back into brew kettle.
3. Jimmy-rig set up: Put a baker's rack on top of the kettle, and a colander on top of the baker's rack. Place bag of grains into colander so that all drippings return to brew kettle.
4. Slowly pour 170-degree sparge water onto grains, making sure to disperse adequately over grains.
5. Use brew kettle lid to press bagged grains until most of the liquid is squeezed out.
6. Place bag of grains in large plastic bowl to collect final drippings (usually not much). Later add those drippings to the boil.
7. Take volume measurement and collect gravity sample to determine grain absorption and brewhouse efficiency.
8. Top off with distilled water until boil volume reaches 4 gallons.
9. Proceed with boil.

With this method, I usually forfeit .75 gallons to grain absorption. With a 90-minute boil, I will take four gallons of sweet wort to three gallons, which is my target for the fermenter.

A couple questions:

-Do I need to treat the entire four gallons of water at the same time before splitting it up into the brew kettle and "sparge water" pot? Do I need to treat the sparge water differently than the mash water?

-I'm not sure if I'm even doing the sparge right, and I've read that it's unnecessary for BIAB. Really that entire piece of my process is to get to my boil volume of four gallons. I figure if I'm adding topoff water after the mash, I might as well use it to rinse the grains in case I can catch any more sugars. Is there a better way to reach that full boil volume?

-I am still trying to figure out the water chemistry element of brewing. I finally got around to purchasing some lactic acid to get my mash pH right. What's the best way to measure out acid additions? Note I don't have a pH meter and have relied on Bru'n Water to help me reach the mash pH.

 

[beernutz]

In my experience grain crush, mash pH, and length of mash have had the biggest impact on BIAB efficiency. What is your grain milling process?

 

[bleme]

The pre-crushed grains can be an issue. Lots of suppliers offer a finer crush for BIAB. Until you can crush your own, see if that is an option.

I think you are holding too much water back to sparge with. I would only keep a gallon or so and you need to figure in grain absorption so you aren't 'wasting' that top-off water.

You can also increase your efficiency a good deal by squeezing, then 'sparging', then squeezing again. I use cold water to rinse with so I don't burn my hands when I squeeze but it sounds like that isn't an issue for you, although you might be able to get more liquid out of there than you are. By the time I am done squeezing, there is no chance of any drips. I could use that bag of grain as a sponge. Using 170F water just saves some time getting up to boil temp.

 

[TripleC223]

I actually just purchased a Corona hand-crank mill that I'll use on my next batch. I've never used a mill before, but it seems that with BIAB, a fine crush isn't as big of an issue as it is with a traditional mash. I guess I'll double-mill or whatever I need to do to get it as close to flour as possible. That said, is there anything to the notion that a finer crush would elicit tannin extraction from the grain husks?

 

[bleme]

That said, is there anything to the notion that a finer crush would elicit tannin extraction from the grain husks?

Only if it is so fine that it goes through your bag and ends up in the boil. That is one area where one of the polyester voile bags (Like Wilserbrewer's) really benefit as their mesh is so much finer.

 

[AHagne]

I too also struggle with efficiency and my process is similar to yours. I pack mine in wool blankets instead of oven, only resulting in 2-3c drop. I’ve read most conversion happens in the first 15-20mins. What i dont understand is how not sparging, as recommended in for example beersmith, results in a higher efficiency. Also, i recall reading squeezing bag results in the extraction of unwanted tannins.

 

[chickypad]

My process is similar to yours (I also do 3 gal batch size with 10qt mash and 6-7 qt sparge) and I get 80+% mash efficiency. A few minor differences:
- For 5-7 lb grainbills I lose about 0.5 gal, your loss sounds more a regular tun so you are losing a little efficiency there. I put the bag in a collander over the pot but let it drain well, then give it a good final squeeze.
- If you're going to sparge I think dunk sparging gets better efficiency than the pour over. I dunk my bag in the sparge water, stir the crap out of it, then drain and squeeze.

As others have mentioned crush is often a big factor. There is no concern for tannins if your pH is right - crush, crush away. You can check on your conversion efficiency by taking a gravity of the first runnings, then check it according to the table on Kai's site linked below - about 2/3 the way down the page. You should be near 100% conversion if you have good crush and mash parameters.

http://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficiency

 

[chickypad]

I too also struggle with efficiency and my process is similar to yours. I pack mine in wool blankets instead of oven, only resulting in 2-3c drop. I’ve read most conversion happens in the first 15-20mins. What i dont understand is how not sparging, as recommended in for example beersmith, results in a higher efficiency. Also, i recall reading squeezing bag results in the extraction of unwanted tannins.

You do get a bit higher efficiency with the sparge. It's just that with BIAB many people don't need to sparge to get good efficiency. You make up the difference by being able to crush a lot finer, and also having less loss to absorption by squeezing/draining the bag. Squeezing doesn't give tannins, that's an old myth that has been convincingly disproven by the many of us who brew this way.

 

[AHagne]

You do get a bit higher efficiency with the sparge. It's just that with BIAB many people don't need to sparge to get good efficiency. You make up the difference by being able to crush a lot finer, and also having less loss to absorption by squeezing/draining the bag. Squeezing doesn't give tannins, that's an old myth that has been convincingly disproven by the many of us who brew this way.

Alright, when i go to my local brewhop (in Norway) they ask what i brew in, i say BIAB and i get a crush. Is there a measurment, read number, for crushing that i can tell them and see if it works better? Screw old myths, i’ll squeeze from now on, thanks!

 

[brew703]

If you are not using Priceless Brewing's calculator, download it to figure your strike water volume. I used to brew 3 gallon batches and I believe I used around 5.5 to 6 gal's total. But I do full volume mashes.

As for your grains, get your LHBS to crush or double crush then run them through your corona mill. That should help with your efficiency.

How much total water are you using for 3 gal batches? if it's more than 6 gallons then you are using too much.

You can always add 10% more malt to your recipe which would give you a higher efficiency. My efficiency is usually mid to upper 70's sometimes low 80's.

Until you get a PH meter you are always going to assume that Bru N Water is correct. I have a cheap PH meter and it jumps around but it gets me close to what I want. I just could not justify spending $100+ for a good ph meter.

 

[wilserbrewer]

My comments...

Add grain bag to kettle when at strike temp, not before.

Rather than pouring sparge water through grain, dunk sparge the bag in the sparge water and add that to kettle.

Most importantly, be sure you are steering with an acceptable crush, even the best process doesn’t work with a lousy crush

 

[chickypad]

Alright, when i go to my local brewhop (in Norway) they ask what i brew in, i say BIAB and i get a crush. Is there a measurment, read number, for crushing that i can tell them and see if it works better? Screw old myths, i’ll squeeze from now on, thanks!

For regular mash tun I think .038-.040 is a common range people use. I think a lot of brewshops are set .045 and up. For BIAB you can easily go .030, I've seen folks use lower than that. I used a credit card in setting up my mill, which is reportedly in the .030-.032 range. That's thousandths of an inch I think, so you may need to convert to metric.

 

[AHagne]

For regular mash tun I think .038-.040 is a common range people use. I think a lot of brewshops are set .045 and up. For BIAB you can easily go .030, I've seen folks use lower than that. I used a credit card in setting up my mill, which is reportedly in the .030-.032 range. That's thousandths of an inch I think, so you may need to convert to metric.

Thanks! I’ll try that and see how it goes.

 

[LittleRiver]

...efficiency has ranged from 45% to 65%, though my last batch was disappointingly on the low end of that spectrum....

Your process basically looks good to me. If you don't have control of your crush, it is good that you have been doing a sparge.

I'll chime in with everyone else, crush your own grains, with a small gap setting on your mill. When you do that, sparging will become entirely optional.

I went with the Kegco mill, set to .025 inches. My efficiency immediately went up to over 80%, without sparging.

A no sparge full volume mash is just a beautifully simple thing, it works so well.

 

[mongoose33]

When I was doing a traditional mash tun, I crushed with a gap of .035. When I switched to BIAB, on the suggestion of Morrie, I narrowed the gap to .020. Imagine my surprise and delight when I found I had the same efficiency!

Now, doing LODO brewing I'm back to my mash tun. Crush w/ a 3-roll mill is back to .035.

Here's the thing, and why others are suggesting your crush is the culprit: I'd measure pH at 15 minutes and stir at both 15- and 30-minutes when going BIAB. I had 90 percent of my conversion done at 30 minutes, and it was only to gain the last few points, and ensure flavors had a chance to enter the water, that i went the full hour.

Now, with the wider gap, wow. It's SLOW. Whereas w/ the narrow BIAB gap I might get in the 1.045 range by 30 minutes, I might be lucky to get 1.025 now. But here's the thing: by the end of the hour, slow as it might be, I get full conversion. That's largely due to much larger grain particles and less flour, which is what I want.

So, unless your crush is VERY coarse, this should work. Further, your water/grist ratio may have something to do with this. When I did BIAB, all the water went into the kettle (7.25 gallons for a 5-gallon batch). The thinness of the grist promotes conversion, as far as I can tell. I do the same water/grist ratio w/ LODO, but it just takes longer.

 

[Greytop]

When I first started, my LHBS complained about double-crushing (said it made too much dust) so I bought a Cereal Killer and double-crushed it myself. It made a huge difference. The Wilser bags allow me to go with as fine a crush as I want without worry. I also dunk sparge in a 5 gallon bucket after letting the bag drain. I sparge with 1 to 1.5 gallons of room temp water for a 5.5 gallon batch, so your sparge qty. seems high. I open the bag once its in the bucket and pour the sparge water into the heart of the grain, give it a good stir, and let it set for a few minutes before returning it to my hook above the kettle. Then I dump the sparge water into the BK and squeeze the crap out of the bag.

I would also recommend that you check your thermometers for proper calibration. Having your strike water at 165° for a mash at around 150° and then putting it in a 170° oven seems high on both ends. Are you refrigerating your grain? Mine is room temp when it goes in the pot which makes my strike/mash temps a lot closer. Don't know if that makes a difference or not.

 

[Redpappy]

My comments...

Add grain bag to kettle when at strike temp, not before.

What’s the purpose for waiting till you hit strike temp before adding your bag?

 

[wilserbrewer]

What’s the purpose for waiting till you hit strike temp before adding your bag?

I ask what’s the purpose of adding the bag as you heat to strike temp?

Lol just kidding....with the flame on you can burn the sides of the bag from heat wafting up the side of the kettle.

Just the way I’ve always done it, just seems more logical to incorporate the bag when you need it and not before...bags don’t like heat!!!

My thinking and process...heat to temp - add bag and grain.

 

[Browne]

I had variations when measuring my post boil gravity. A more experienced homebrewer told me to properly stir the wort ... sugar (heavier wort) tends to drop in pot. I agree with Greytop, problem might be in measurements, not in brewing process (yours seems pretty sound).

... fwiw, I would only add bag to water after reaching strike temp.

 

[LostHopper]

Lol just kidding....with the flame on you can burn the sides of the bag from heat wafting up the side of the kettle.

.

Mr Wilser is not kidding about this. I no longer put heat to kettle with bag in place. I'm a quick learner after scorching a bag. May be more of a risk with big propane burner than stove top

 

[Novacor]

I ask what’s the purpose of adding the bag as you heat to strike temp?

Lol just kidding....with the flame on you can burn the sides of the bag from heat wafting up the side of the kettle.

Just the way I’ve always done it, just seems more logical to incorporate the bag when you need it and not before...bags don’t like heat!!!

My thinking and process...heat to temp - add bag and grain.

I was actually just thinking about this the other day. Does adding the bag affect your strike temp at all, or am I over thinking it?

 

[TripleC223]

Thanks everyone for the input. Again, I just purchased a Corona mill, so I will now (theoretically) be able to better mill my grains.

The main issue I run into with mash volume is my brew kettle. It's a 5-gallon capacity, and with 2 gallons of water and 5-7 pounds of train, it's about 3/4 of the way full. I can probably stretch it to as much as 3 gallons of water, so I'll also give that a try.

FWIW, after putting away a few bottles of my first BIAB, I'll say the ABV seems higher than what I measured. So perhaps my efficiency is greater than measured.

 

[soccerdad]

I agree with the dunk sparge idea over the pour over. And I would just dunk with one gallon if your grain Bill is under 10 pounds. 5 gallon bucket works well for this .. drain first running back to kettle .. lower grains into sparge in bucket .. stirr good .. drain over bucket and add to kettle.

 

[wilserbrewer]

I was actually just thinking about this the other day. Does adding the bag affect your strike temp at all, or am I over thinking it?

Yes, while adding the bag does affect strike temp to a very small degree, you are way over thinking it. The weight of the bag is insignificant to the weight of the grain bill.

Unless of course you can preheat the bag lol. Don’t try it

 

[TripleC223]

Thank you all for the tips. I took all your advice and got what I believe is a superb efficiency with the batch I'm currently boiling. I was hoping to have someone double-check my math on brewhouse efficiency to make sure I'm not just miscalculating something somewhere. I used the Brewer's Friend brewhouse efficiency calculator, and it gave me ~85% efficiency.

From 4 gallons of pre-boil water (2.5 gallon in mash, 1.5 as a pour-over sparge), I yielded 3.75 gallons of pre-boil wort that measures in at 1.044 (temp of sample right now is ~75 deg). That would be only a .25-gallon loss to grain absorption, which is far and away the lowest I've ever had.

It's a 3-gallon batch. The grain bill is 5 pounds of 2-row and 6 oz of Caramel 15L. That's all. I was planning to use some DME to reach my intended OG, but it looks like I overshot that with just the grain (!).

The inaugural grind from my grain mill went great. I double-bagged the BIAB (2 paint strainer bags) just in case the grind was too fine, and it seemed to work out well. Squeezed/squished the hell out of the bag, which may be why I was able to limit my grain absorption.

Also stirred the wort before I pulled the sample. Thanks for that tip as well.