Originally Posted by Fordzilla
Sorry if this was already discussed. Whats the advantage of a 90 minute mash? I'm still new to BIAab but I seem to do OK with 60 minutes. Has anyone done any experiments with 60 vs 90 and compared efficiency?
We are experimenting with this at another BIAB website.
Here are results of my last two brews:
15 minutes: 7.4 brix/1.0282 (mash temp 154F)
30 minutes: 7.8 brix/1.0298 (mash temp 154F)
45 minutes: 8.6 brix/1.0329 (mash temp 154F)
60 minutes: 10.0 brix/1.0384 (mash temp 152F)
75 minutes: 10.5 brix/1.0404 (mash temp 150F)
I then ramped temp up to mashout (168F) over 15 minutes:
90 minutes: 11.2 brix/1.0432 (mash temp 168F)
I let it sit at mashout temp for 15 minutes:
105 minutes: 11.4 brix/1.0440 (mash temp 167F)
Pull bag and squeeze:
pre-boil: 11.5 brix/1.0444 (mash temp N/A)
60 minutes: 7.4 brix/1.0282 (mash temp 154F)
end of 90 minute mash: 7.8 brix/1.0298 (mash temp 154F)
end of 10 minute mashout (168F): 9.0 brix/1.0345
pre-boil (after pulling and squeezing bag): 9.2 brix/1.0353
*(brix converted to sg using Sean Terrill's calculator)
Granted this is a very limited data set but it appears that:
A) the extra 30 minutes in the mash does indeed result in more extraction/higher gravity
B) squeezing the crap out of the bag may not be worth the extra .0005 gravity point!