First time BIAB - 40% eff. - write up of what I did (perhaps wrong?)

So I tried BIAB yesterday and had some mixed results. I decided to use my 7.5 gallon brew pot with a 15 lb grain bill. I wanted to use my kitchen stove since it was raining outside and I wouldn't need all the equipment I normally do since I was going for BIAB with no sparge. I got great performance out of my kitchen stove - it brought everything up to temp much faster than I expected.

12:15 put 6.5 gallons of spring / bottled water and ph5.2 in pot and turned on stove. - Water was 60*. I then put in upside down strainer to keep grainbag off the bottom of the pan.

12:35 water was at 105* I doughed in with everything but the pound of sugar. I then stirred regularly. It seem to take a while so I left the stove to check on some stuff and returned 20 minutes later to find the thermometer at 170. I turned off the gas and stirred some more and took the lid off. It took about 20 minutes to get it down in the mid 150s. I let it sit and mash with the lid off for another 75 minutes.

2:15 - pulled the grain bag out and put it in a colander over an ale pail to drain. Pressed down on it with a plate to squeeze out the last drops I could.


While grain bag was draining I checked out the pot with he wort in it and pulled out the upside down metal colander using the chain I attached to it. The wort was super cloudy and had a chunks of stuff in it. I decided it was too cloudy so I poured the stuff from the bucket into the pot and then rinsed the bucket and added a 5 gallon paint strainer.

I drained the pot into the bag/bucket and ended up with about a softball size load of schmutz that I don't know how it made it through the grain bag. I then gave the pot a quick scrub to get a lot of the residue off the sides and poured the bucket back in the pot and turned on the gas.

I added 12 drops of ferm cap (first time using this) to preven boil overs (since it was on my kitchen stove. The rest of the 90 minute boil went pretty normally but I had a lot of trub - perhaps a gallon or more after chilling. I usually don't have half that much.

So what did I do to get such horrible efficiency? Was it the mash temp overshoot?

I decided to try BIAB since I have gotten hit and miss efficiency with my cooler MLT but if this is what I can expect, I think I'll stick with the cooler.

Patirck said:

I decided to use my 7.5 gallon brew pot with a 15 lb grain bill

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how much water did you use for mash? According to my calcualtions I need roughly 8 gallons of water to startr with for 12 lbs of grain. Thats not going to happen with 7.5 gallon brew pot. I think you way off on water to grain ratio. Thats a key factor for good efficency in BIAB

I agree, I think you left a lot of sugars on your grains by not having enough water. BIAB no sparge really means to add the water you would have used to sparge in the pot with your strike water. I would have put closer to 9 - 9.5 gallons of water in the pot, if you had a large enough pot that is.

paraordnance said:

how much water did you use for mash? According to my calcualtions I need roughly 8 gallons of water to startr with for 12 lbs of grain. Thats not going to happen with 7.5 gallon brew pot. I think you way off on water to grain ratio. Thats a key factor for good efficency in BIAB

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Yeah, this is what I thought as well. When I was doing BIAB I was also using a 7.5gal kettle, and I would try and keep my grain bill below 10lbs max. I still only got about 60% eff on average.

paraordnance said:

how much water did you use for mash? According to my calcualtions I need roughly 8 gallons of water to startr with for 12 lbs of grain. Thats not going to happen with 7.5 gallon brew pot. I think you way off on water to grain ratio. Thats a key factor for good efficency in BIAB

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Paraordnance. You do know your W:G ratio is usually in Liters or Quarts yea? 12 lbs grain @ 1.5 Liters per lb is 18 liters or 4.5 gallons. Even at 2 liters/ lb, you're sitting at about 6 gallons which I've found is a bit high.

WIth a leaner ratio (1.25-1.5), you get quicker conversion and then water left over. With the extra water, you can heat it up in another pot and tea bag your grains in that to rinse out some of the loose sugar. That should increase you efficiency 10-15%.

Edit: See - https://www.homebrewtalk.com/f39/easy-partial-mash-brewing-pics-75231/ (he uses a lower w/g ratio and his process could easily be scaled to accomidate ag) and http://www.rackers.org/calcs.shtml for volume calculations.

I guess I need to chalk this up to experience. Is it normal to have that much crap after you pull the grain bag out of the pot? I was hoping to find a process that would make for easy, no sparge, single vessel stovetop brewing. I guess I'm aiming high.

Also, I've found that even if you have enough water, if your grains are in too small of a bag, your effective mash thickness will be way too dry. I've found I can't go over about 12 lbs of grain before it gets too thick with the bag I have.

How I calculate mash thickness- I've found I basically want as much water as possible in the mash, and go from there. I made this calculator-
http://up.jamesnweber.com/_brew/biabcalcs.html

Basically, you give it how big your tun is, and how much grain, and it calculates your maximum mash thickness, and then how much water to use. Most calcs I've found work the other way, which is annoying for brew in a bag. It also calculates strike temp if you want.

yep... its normal.. the wort will be cloudy when the grain bag is pulled.. but that's OK.. and I agree with the others.. for a no sparge BIAB, you need ALL the water in the pot.. including what you'd sparge with, boil off, trub loss, and water absorbed by the grains. fora 12lb grain bill I start with 8-8.5 gallons. I lose almost half a gallon to trub. for a 7.5 gallon pot you'd have to to dunk sparge it in order to get all sugars.. also, if you have your grains crushed at the LHBS have it double crushed.. if you have your own mill, crush it real fine..

gregpio85 said:

Paraordnance. You do know your W:G ratio is usually in Liters or Quarts yea? 12 lbs grain @ 1.5 Liters per lb is 18 liters or 4.5 gallons. Even at 2 liters/ lb, you're sitting at about 6 gallons which I've found is a bit high.

WIth a leaner ratio (1.25-1.5), you get quicker conversion and then water left over. With the extra water, you can heat it up in another pot and tea bag your grains in that to rinse out some of the loose sugar. That should increase you efficiency 10-15%.

Edit: See - https://www.homebrewtalk.com/f39/easy-partial-mash-brewing-pics-75231/ (he uses a lower w/g ratio and his process could easily be scaled to accomidate ag) and http://www.rackers.org/calcs.shtml for volume calculations.

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you obviously didn't do your homework when you dived in BIAB. 1.25-1.5 W:G ration only applies if you mashing in MLT, when you do a BIAB water to grain ration is much higher than that because you do not sparge, as Mysticmead already said you need to add ALL water right from the start and mash in that amount. Make yourself a favour, go to a BIABrewer.info and download BIAB Calculator wich will help you to figure your total amount of water you need for your mash. I BIAB all the time and my efficency was at 68% lowest, usually 70-75%. I would however use about 9 gallons of water for 15 lbs of grain to hit these numbers. So you completelly off on W:G ratio with your tiny brew pot you have.

paraordnance said:

you obviously didn't do your homework when you dived in BIAB. 1.25-1.5 W:G ration only applies if you mashing in MLT, when you do a BIAB water to grain ration is much higher than that because you do not sparge, as Mysticmead already said you need to add ALL water right from the start and mash in that amount. Make yourself a favour, go to a BIABrewer.info and download BIAB Calculator wich will help you to figure your total amount of water you need for your mash. I BIAB all the time and my efficency was at 68% lowest, usually 70-75%. I would however use about 9 gallons of water for 15 lbs of grain to hit these numbers. So you completelly off on W:G ratio with your tiny brew pot you have.

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Thanks for the heads up. I'm mashing in my small kettles, but sparging with my bags dropped into my bottling bucket, recirculating wort with 160 degree water slowly added.

I was unaware that BIAB had no tea-bag/sparge in a separate kettle. I'll check out that link. Sorry for the confusion everyone. There's my education for the day!

Cheers

I've done a few BIAB mashes and I've always hit about 70% efficiency. I don't think the amount of the water was a problem. I usually aim for about 1.5qt/lb of water. For you that would mean only about 5.5 gallons of water which is fine for your pot. I also use a second pot with hot water in it to sparge in. For 15lbs of grain you would need at least a 6gallon pot and could probably sparge with 2 or 3 gallons of water. Boil that and the mash water down and added them both to your brew pot (whichever pot it is). See the sticky about easy BIAB mashing in the beginners forum. It definitely will increase your efficiency. Even if you don't sparge, you efficiency should be way above 40%.

I think your bigger problem probably was your temperature control. I usually find it's almost impossible to control the temperature on the stove. There will usually be a 10 degree or more variation between the top and the bottom of the pot even if you are stirring. The best way is to heat the water to the correct adjusted temperature, add the grain, stir, cover, and let it sit. If you let the mash hit 170, it's likely all the enzymes required for mashing had denatured. If you overshoot your temperatures you need to drop them quickly or you are out of luck. Also, it can help to get some iodine. Use an eyedropper, collect some wort and put a few drops in a shot glass with a drop of iodine. If it turns dark blue/black, there are still starches and your mash isn't complete.

Another issue is grain absorb; I think with that grain bill you could be hovering around 2 gallons of water loss due to the grain itself - leaving you with only 4.5 gallons, for both your mash and sparge water - not enough.....

Add that to some of the above and I think you had a number of small process challenges that you can sort out given a little more experimentation.

Try making a 2.5 g batch in your pot using water volume calculated from some of the BIAB folks adjusted by your grain bill. I think you will be suprised by how much water your should have in your pot.