Biab questions

SSBrew - 728
Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
P

patchedboard

Well-Known Member
Joined
Mar 29, 2012
Messages
53
Reaction score
7
Location
Fargo
So I've done biab twice now and both times on five gallon batches and each time they come out a gallon short going into the fermenter. The numbers look good but just a gallon short. Second question...I add a gallon of water to make up the missing gallon, dies that screw up my og? Should I just go with the batch a gallon short?
 
I am always about a gallon lower than what I started with at the end of my BIAB batches. The grain absorbs a lot and some evaporates. You should mash with more water to begin with to get closer to your final volume into the fermentor. I'm sure the beer will be ok, as long as the recipe was for 5 gallons.
 
But did i screw up the batch by adding another gallon of water to bring it back up to 5 gallons?
 
patchedboard said:
But did i screw up the batch by adding another gallon of water to bring it back up to 5 gallons?
Click to expand...

If your gravity was at the number you expected while it was only 4 gallons, then yes! By diluting it with a gallon you have lowered the OG. If the gravity was higher than you expected then by diluting it would likely bring you closer to the OG you expected..
 
Ok...well...that explains why the last batch tastes watered down. Good to know for next time. Either way...watered could be much worse...
 
what is your volume before starting to boil? for a 5 gallon batch, you would normally start with around 6 to 6.5 gallons to allow for boil off. Boil off rates will vary depending on your setup.
 
About five gallons...I kinda figured there was loss but didn't know what too do about it so I just added the extra gallon at the end...
 
Adjust your starting amounts to account for grain absorption and boil off. As said previously you will need 6 - 6.5 gallons pre-boil.

I did 2 and ended up with too much wort and lower OG than anticipated. I figured out that I was not losing as much to grain absorption since I was squeezing the heck out of the bag.
 
patchedboard said:
About five gallons...I kinda figured there was loss but didn't know what too do about it so I just added the extra gallon at the end...
Click to expand...

Are you doing any kind of sparge? I usually mash with about 4 gallons of water for an average grain bill. Then put bag on grill grate over pot and squeeze. Then I pour/ladel pour hot water over grains, letting it drain into pot. Squeeze again and repeat until I have about 6.5 gallons and then start boil. Sparging will get more fementables out of your grain.
 
Seven's primer on biab is really helpful. I'd read that thread to help hit your volumes spot on.

Total water = batch size + grain absorption + evaporation + trub loss

.074 x grain weight in lbs = grain absorption

Evaporation estimate = 1 gallon per hour of boil

Trub loss = .25 - .5 gallons
 
My last BIAB on Sunday (13lb grain bill) I used a total of 9 3/4 gal of water to end up with 5.5 gls post boil. That accounts for grain absorption, boil off, and about 1/3 gal left in the kettle(hop/cold break material) after transfer to the fermenter. There are a lot of programs available that account for all these factors. I use Nelsons Beer quick calculator. It's easy and free.
 

Similar threads

T
Mash Volume Higher than Boil Volume eHERMS
Replies
5
Views
624
Town9
T
D
Looking for a Kettle
Replies
28
Views
1K
DuhokBrewer
D
DonH
For Sale SoCal - FULL 20gal BIAB /Keezer / Ferm Fridge
Replies
6
Views
900
DonH
DonH
AlcheMania
Pressure cooker: A decoction hack?
2 3
Replies
85
Views
5K
MicroMickey
MicroMickey
M
DIY Electric BIAB system that could double as a Sous Vide system?
Replies
2
Views
464
Bobby_M
Bobby_M

Latest posts

Back
Top