About to start my second BIAB and would like some comments

Obligatory first post and questions.

Last weekend I did a no sparge BIAB of da yooper's house pale ale.. I thought I nailed it, but I only hit 64% efficiency. I'm actually quite happy with that, but I'm looking to improve. I'm doing cream of three crops tomorrow and I'm very hopeful. I'm looking for just a little guidance though:

1. I double crushed my grain this time.
2. Last time, I didn't stir during my mash. This time I plan on opening the lid every 5 minutes to give a stir and adjust the temperature.
3. For mashout I brought the temperature up to 170 then immediately removed the bag. This time I plan on soaking it for 15 minutes.
4. I'm having trouble planning my grain/corn/rice absorption. My pot is 9 Gallons, but I'm guesssing I won't be able to do full volume to hit 7 gallons pre-boil. Maybe I'll sparge with the remainder into a bucket/pot?

I'm hoping, that armed with these 4 questions answered / confirmed I'll be able to gain at least 10 percentages?

Thanks for your help!

1. This will likely help
2. I wouldn't stir every 5 minutes. You'l loose a lot of heat and I don't think it's necessary. You also risk tannin extraction by overstirring. Try stirring 2 or 3 times during your mash.
3. This won't hurt your beer but I don't think this will improve efficiency (I'm not sure thought)
4. You can use a second pot for sparging. See this post: https://www.homebrewtalk.com/f39/easy-partial-mash-brewing-pics-75231/

It seems that most brewers end up between 68 and 78 percent efficiency so if you can pick up 5 more points you are doing fine.

Good luck!

I do BIAB exclusively and am getting 80 - 83% efficiency. What is working for me:

Double crush grains
90 minute mash, stirring every 30 minutes
Squeeze that bag, squeeze it man! I have a big colander/food mill that I put over a second pot. I put the bag of grains in that sucker and push down hard, move the bag around and squeeze.

For planning absorption - start measuring your water before and after you mash and record your findings. It will take a few brew sessions to dial in. I'm on my 13th BIAB brew session, and I'm just now dialing in on the last three brews. Copious notes and measurements are key.

1. Definitely double crush grains.
2. You really only need to stir when you mash in to normalize/average out the temps throughout the mash, then again when you mashout to normalize/average out the temps throughout the mash. No need to stir DURING the mash, as you'll be dissipating heat.
3. 10-15 mashout is a good idea. Just remember to stir constantly in mashout, or you'll end up with boiling wort surrounding under 170 degree pockets in your mash. Stirring all over while it's on heat will normalize the temp throughout.
4. All grains are different, but the pale two-row I buy absorbs 0.7 gallons per 10 lbs of grain, so that's a good average to start with. Smaller grains and finer crushes are going to absorb a bit more, but not much either way. The highest absorbsion I've ever heard of is around 1.3 gallons and the lowest is around 0.4 gallons (per 10 lbs). If you do want to do a sparge, you would might want to do this INSTEAD of a mashout. Subtract 2-3 gallons from your starting volume for the sparge volume, then after the mash pull the bag and sparge the 2-3 gallons of 175-178 degree water through the grains, then drain/squeeze your bag.

Also remember that if you are having trouble with efficiency, you can always just use the full grain bill but either cut the total water volume by like 1/2 gallon or boil for 75-90 minutes instead of 60 minutes. Less water = more concentrated wort = higher efficiency.

I do a batch sparge with my BIAB and have been doing pretty well. I got 75% efficiency this last time so I am happy with that. What I do is just use 1.25qt/lb for my mash, use 0.6% absorption and calculate what I will need for my sparge water. Like mentioned above, squeeze the crap out of your bag to get all the good stuff out. I bring my sparge water up to 170 and then stir every so often during a 15-20 minute sparge...then squeeze again.

I wouldn't get overly concerned with getting high efficiency, the most important thing is consistency. higher efficiency doesnt equal better beer, in fact it can lead to worse beer.

TopherM said:

Less water = more concentrated wort = higher efficiency.

Click to expand...

not true at all. efficiency is based off volume, so having a higher gravity at a lower volume doesnt change it.

Sarrsipius said:

2. I wouldn't stir every 5 minutes. You'l loose a lot of heat and I don't think it's necessary. You also risk tannin extraction by overstirring.

Click to expand...

I agree, stirring every 5 mins isn't useful, but AFAIK that shouldn't effect tannins. the main factor for tannin extraction is pH and stirring isn't going to effect that.

Thank you all!!! :rockin: my post got delayed (probably because I'm new) and I brewed on Monday without these comments. Your advice was spot on though! Calculators show me at 77% efficiency. Efficiency aside there's lots I could improve on to have a better brew.

1. The double crush helped.. although I think the gap on the crusher at the lhbs is quite wide and the second crush really only crushed grains that didn't get crushed on the first run through. I need to research more on this I think.
2. I stirred about 10 times in my 90 minute mash. Temperature control was an issue, and I wrestled with boiling water to raise it. Luckily it was a hot day, so I didn't lose that much.. This was to much micro-managing. Next time I'll stir 2 or three times. :cross:
3. I had trouble hitting 170 for my mash-out, but got there eventually.. I was really worried about scorching the bag so I may not have had enough heat on it. I wish I had TopherM's advice earlier, and had stirred more during this phase.
4. I did sparge in a second pot, and squeezed the heck out of it.

The biggest thing I need to work on next is trub. I'm not sure if it was the double crush, or the squeezing. Once I dropped my temp I didn't give it a rest.. which probably accounts for it. Here's a shot of my fermenter 48 hours in:

So, two weeks later I thought I would check in and see where this guy fermented at. It's cleared up a bit, but still had some cloudiness.. I gave it a taste and it was certainly sweet.

The Gravity is sitting at 1.034
The temperature gauge on my Carboy reads 70F


Pre boil I collected 6.8 Gallons at 1.038
I boiled down to 5.3 and was at 1.051

My grain bill was:
6lbs 2 row pale
2.5lbs flaked corn
1lb flaked rice

I shaked the heck out of it(3 minutes?) to aerate and then pitched a Wyeast 1056(date was 2 weeks old) smack pack.. Fermentation was a little weak to start but it had some churn. The krausen was good, but I was expecting blowoff and never got it.

Thoughts?

what was your mash temp and was that gravity reading with a hydrometer or refractometer?

I mashed at 155F.. After a bit of reading I'm doubting my thermometer. It came with my turkey fryer. So next batch I'll go get a more trusted one.

All reading were done using a hydrometer and I used http://www.brewersfriend.com/hydrometer-temp/ to adjust.

The hydrometer seems accurate, I read 1.0 for water.

sounds like the thermometer was prolly off then. you could try picking up some amylase from your LHBS and adding a Tbs to your fermenter. if the mash temp was the problem that'll fix it