Recipe Adjustments for BIAB?

[nyrmc23]

Hey gang. I'm making the jump to my first BIAB and I had a question about recipe adjustments, in that are there any? More specifically, I have a recipe book that uses a sparging method, so for a 5 gal brew (I'll be doing 3 gal) it calls for heating 3.5 gallons for the mash and an additional 3 gallons for the sparge, bringing things to 5.5 gallons for the boil (assuming we lose a gallon during the mash in.

So long story not too short, for BIAB, what would be the water volume since there's no sparging?

 

[RPh_Guy]

You need enough water to reach your batch size and make up for losses during the brew process.

You've been brewing all grain already?
You should know your grain absorption, boil-off, trub loss, and any other losses if any.

The only difference between sparging and not sparging is a modest decrease in efficiency, which may be offset by a tighter crush.
Changing the crush may change the water lost to grain absorption.
How aggressively/how long you let the grain bay drain may also slightly change the grain absorption loss.

You'll just need to make some educated guesses for the first time and then measure volume and adjust next time.

Hope this helps

 

[nyrmc23]

I'm still very much a beginner with brewing. I've done about three all-grain batches, 2 of which were quite good. But want to try BIAB. So I should start with the full water volume in the mash and crush the grain tighter?

 

[RPh_Guy]

I'm still very much a beginner with brewing. I've done about three all-grain batches, 2 of which were quite good. But want to try BIAB. So I should start with the full water volume in the mash and crush the grain tighter?

That's what I would do

Measure your losses so you can adjust next time.

 

[rjs3273]

I only did a full volume mash once and ended up with a lower overall efficiency. As I say, I only tried it once so I do not have any very convincing numbers to prove anything. For a 5gal batch, generally I mash with something in the range of 3-4 USgal and then do a couple of 1.5gal batch sparges in a brew bucket to get me up to my starting boil volume.

It is obviously a bit more effort but I don't think it costs me very much time because I can batch sparge in a bucket while I am bringing the first wort up to a boil. I generally find that I get the second batch sparge into the kettle just as it is about to boil so it all works out quite well.

As for why I do it that way, I think it is just the process I figured out for myself before I asked anyone else and just carry on. Also I only have an 8 USgal kettle. If I have a large grain bill I cannot fit the grain and the full volume of water in there. The biggest grain bill I can easily do in the 8gal kettle is about 16lbs.

In short, what I do is really pretty close to what your recipe says for a classic all grain with no adjustment. I really should try doing a full volume mash again and more carefully testing the efficiency.

 

[LittleRiver]

...recipe adjustments...are there any?... what would be the water volume since there's no sparging?

In full volume BIAB if you crush your grain fine (~.025" on a roller mill, or a corn mill that has been set tight) you should be able to consistently hit or exceed recipe targets with no separate sparge steps, and no adjustments to the recipe. You have the option of adding sparge steps if you want to bump up your ABV, but you should not need those steps to reach standard recipe targets.

Try the free Priceless BIAB Calculator to plan your water volumes. It will give you a lot more information than you need, but you can just pick the info you do need. I use it to plan my starting and ending water volumes. During brewing I use the depth measurements the calculator provides.

 

[CascadesBrewer]

Good luck! I agree with the "make some educated guesses for the first time and then measure volume and adjust next time" advice...same for about any process change.

Back when I fly sparged, I did not pay much attention to grain absorption (just prepped a gallon or so more water than I likely needed), but the grain absorption for BIAB seems to be less than for a lauter process. Somewhere around 0.05 gal/lb is about what I see (where 0.1 gal/lb seems to be a popular value for lauter). So about 1/2 gal of water for 10 lbs of grain.

Grain crush seems to impact BIAB efficiency quite a bit. I don't have a lot of data to back that up myself, as I have done all my batches with a 0.025" crush, but the stove top batch I did with my GF with store crushed grains was quite a bit lower efficiency. Something to be aware of. Your efficiency could go up 10% or drop 10% or be somewhere between those.

 

[rjs3273]

Grain crush seems to impact BIAB efficiency quite a bit.

I'll second that. Since I bought my own mill, my numbers have all been consistent. 95% conversion and 70% into the fermentor. Efficiency was much more variable when I bought crushed grain. Looking through my logs, when I noted a coarse or poor crush, it has correlated to lower efficiency.

 

[CascadesBrewer]

Efficiency was much more variable when I bought crushed grain.

That was one of the big motivators when I first got a mill. My local shop did not have a mill available for base malt (they would grind a few pounds of specialty malts for you in the back). Between their bags of precrushed, and various online vendors, my efficiency was all over the board.

I don't have exact numbers to compare to now vs my old lauter process because I did not take pre-boil readings and I did not take accurate post boil volume measurements. I have been seeing around 90% mash efficiency and I have had to scale back my recipes by a pound or so of base malt, and I still come in with higher OGs than with my old process. I see some BIAB brewers take a hit on efficiency and grain crush seems to be the big factor there. I am still trying to tune my BIAB process but around 75% to 80% overall efficiency seems the range I am in for 5 gal with a sparge, and 70% to 75% for smaller stove top full volume mash.

 

[dwhite60]

I just completed my second BIAB, today. I tried this once before and had horrible low efficiency, like 50%. Beer wasn't close to what I wanted.

So, today I started with 5 lbs of grain. I crushed pretty tight. I thought maybe I should open it up some but I went with it.

2.5 gallon batch + 1.0 gallon boil-off in an hour + 0.6 gallons water absorption came to 4.1 gallons strike water.
Mash in at 159F. Mash 90 minutes where it fell to 149F. Pulled the bag, put in a colander over a bucket to drain. Collected the runnings and added to the boil.

My efficiency came out to 75% which I was VERY pleased with. Interested to see how this batch turns out. My lautering days may be over. I usually only do 2.5 to 3 gallon batches so this method works perfectly for me.

Oh, doing a BIAB with this volume cut an hour off my brew day.

All the Best,
D. White