9 replies to this topic

[zymot]

I screwed up my calculation. First I used John Palmer's .25 qt/lb grain value. 10# recipe = 2.5 qts = .625 gallons. Second, my calculation forgot to convert the 2.5 quarts to .625 gallons.

 

My dynamic test shows the retention value of .070 qts/lb. In short, I used the wrong constant (.25qts/lb not .070 qts/lb) and I miscalculated such that the strike volume was in excess. When I lifted the bag out of the kettle/mash tun  I had much more wort than I wanted. Had to do a boil off to get down to the SG and the in-the-fermentor volume I was shooting for.

 

Otherwise, I am sold on the process. If anybody is moving to all grain, BIAG has many advantages. The disadvantages that I see are #1 you should invest in a 15 gallon kettle/mash tun to cover the bigger grain bills, (ETA on second thought a 20# grain bill is managebale)  #2 figure out where you can mash/boil and hoist a bag out of the kettle.

Edited by zymot, 11 April 2020 - 08:41 PM.

[matt6150]

I over shot my volume as well the other day. Boiled for an extra 20 min to get right. At least it only cost some time.

[shaggaroo]

I guess I do a modified BIAB, really I just mash in a bag, but I'm sold on it... added some angle iron across a couple of joists in the garage so that I can attach the rope and pulley, and away I go...

[HVB]

I use the bag as a BIAB in my boil kettle and I will also use it in my mlt. I like BIAB but sometimes it does not produce clear wort so for some lagers I will go two vessel. For single vessel I have settled on 0.06qts/#.

[neddles]

I screwed up my calculation. First I used John Palmer's .25 qt/lb grain value. 10# recipe = 2.5 qts = .625 gallons. Second, my calculation forgot to convert the 2.5 quarts to .625 gallons.

 

My dynamic test shows the retention value of .070 qts/lb. In short, I used the wrong constant (.25qts/lb not .070 qts/lb) and I miscalculated such that the strike volume was in excess. When I lifted the bag out of the kettle/mash tun  I had much more wort than I wanted. Had to do a boil off to get down to the SG and the in-the-fermentor volume I was shooting for.

 

Otherwise, I am sold on the process. If anybody is moving to all grain, BIAG has many advantages. The disadvantages that I see are #1 you should invest in a 15 gallon kettle/mash tun to cover the bigger grain bills, (ETA on second thought a 20# grain bill is managebale)  #2 figure out where you can mash/boil and hoist a bag out of the kettle.

 

I have a really simple BIAB system that has worked well for me over the years. It's hard for me to imagine brewing any other way. I don't have it in front of me but my retention value is real similar to your .070qt/#. 

Edited by neddles, 12 April 2020 - 06:45 AM.

[zymot]

It all went very good and well, hit my mash temp target, the mash was solid and stable through the entire mash. Then I saw 7.5 gallons at the start of my boil. I boiled an extra hour to get the volume down and the OG up. It is a new boil kettle for me, and I overshot the boil rate and had 4.5 gallons in the ferment bucket.

 

I considered topping the wort off to get to 5.5 gallons. I am using Wyeast 1318 London Ale III. That stuff puts a ton of yeast at the top and you need a blow off tube. Figured I should leave well enough alone, take what the beer gives me and pitched into 4.5 gallons.

[zymot]

I use the bag as a BIAB in my boil kettle and I will also use it in my mlt. I like BIAB but sometimes it does not produce clear wort so for some lagers I will go two vessel. For single vessel I have settled on 0.06qts/#.

 

 

I have a really simple BIAB system that has worked well for me over the years. It's hard for me to imagine brewing any other way. I don't have it in front of me but my retention value is real similar to your .070qt/#. 

Are you sure you guys do not mean 0.07 gal / #, (not qts/#)

 

My test yesterday:

 

Recipe = 10 lb

Strike: 8.25 gal

Sparge/drain/bag lift volume = 7.5 gal

Retention: 8.25 gal - 7.5 gal = 0.75 gal

Rate: 0.75 gal / 10 lb recipe = .075 gal / lb AKA 3.0 qts / lb

 

I was surprised how easy it was to get all the wort out of the bag. Within a few minutes after lifting the bag, I had the 7.5 gallons. As an experiment, I squeezed the bag to see how much additional wort I could get. Not very much. Less than a pint. Certainly not worth the effort.

[neddles]

Are you sure you guys do not mean 0.07 gal / #, (not qts/#)

Sorry, you are correct.

[HVB]

Sorry, you are correct.

Yup,same for me. I blame it on lack of coffee and stay at home beer cellar cleaning/drinking.

[SchwanzBrewer]

I love BIAB. Its so easy. If you get a grill grate for a 20" webber kettle at lowes or homedepot it will fit over most kettles and you can set the bag on it to drain the wort.