Amount of mash water for BIAB

I'm going to brew a 5 gallon Belgian wit as my first BIAB
Ingredients as follows
4.75 lb Belgian Pilsner (2 Row)
3.00 lb White Wheat Malt
2.5 lb Flaked Wheat
0.50 oz Cascade (7.5%) (30min)
0.50 oz Cascade (7.5%) (5 min)
0.50 oz Orange Peel, Bitter (Boil 15.0 min)
0.50 oz Coriander Seed, Crushed (Boil 15.0 min)
1 Pkg Belgian Wit Ale (White Labs #WLP400)

The grain comes to 10.25 LB
A few questions

1) Should I go with 1.25 quarts per pound as my mash water i.e 12.81 quarts water i.e 3.2 pounds or do I need more ?

2) After a 60 min boil, do I not need to sparge and can just press down on the bag. i.e shouldn't be a need to top off to get to 5 LB wort ?

5 gal your goal?

If your not going to sparge you will need more water to start. Enough to account for what the grains soak up plus your boil off.

I did a BIAB this weekend with a 12lb grain bill.
I used 1.5qt/lb (4.5G) and then sparged with 3.5G to get my preboil volume to 6.5G.
After my 60 min boil I had 5.5G to go into the fermenter.

I'm looking for 5.5 to go into the fermenter. I thought the point of BIAB was to keep it simple and there wasn't really a need for sparging i.e everything in one pot. I'm not averse to it, but just haven't read up enough on what it entails beyond slowly dropping hot water (170 degrees ?) into the grains.

If I sparge should I be doing this at roughly the same rate that the wort is dripping down i.e pretty slowly

If it's not going to lead to a significant increase in efficiency, I'd rather just put in more mash water to begin with and keep it simple. But I don't know enough

I just moved from BIAB, but I would use full volume from the beginning. Add the amount you want to go into the fermenter, plus your estimated boil-off volume plus grain absorption amount and start with that. I didn't sparge when I did it - just heated the strike, stirred in the grains (and stirred like crazy,) let it mash, then heated up to a mash-out temp with one more prolonged stirring session. Then I drained and started my boil.

You definitely dont have to sparge, thats up to you. If you dont you need to put all the water in at the begining. Enough to account for your grain absorption and boil off. Your absorption is going to be about .05g/lb and Im guessing your boil off rate to be about 1g/hr. By my calculations your going to want to start with about 6.5 gallons if you want to put 5 gallons in your fermenter. Ive not done this a lot though so I might wait for a few more seasoned vets to chime in.

mcbaumannerb said:

I just moved from BIAB, but I would use full volume from the beginning. Add the amount you want to go into the fermenter, plus your estimated boil-off volume plus grain absorption amount and start with that. I didn't sparge when I did it - just heated the strike, stirred in the grains (and stirred like crazy,) let it mash, then heated up to a mash-out temp with one more prolonged stirring session. Then I drained and started my boil.

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THIS is the correct answer. If you don't know your boil off rate, you may want to boil plain water in your brew pot for an hour and measure how much you lost to determine your boil off amount.

As the_trout said, your absorption rate is about .05. I personally use .08, no big deal. Just multiply that number by the pounds of grain you are using to get the amount of extra water. So

.05 * 10.25 = .51. That's half a gallon.

Don't worry about sparging for now, until you get your BIAB process down. But, if you want to do it, just pull your bag up and heat the water up to 168 and let the grains soak at 168 for ten minutes.

I need 10.5 gal of water for a 6gal batch (23L/5 imperial gal)
That includes space for trub and everything. I do a 70 min mash and 70 min boil. My fav beers are usually mashed at 158.
I use Irish Moss in the last 10 min. I am not sure how people get away with less water. Even at a 60 min boil it was hard to hit 23L. I am thinking its because a lot of recipes use U.S 5 gal (19L).

I do not sparge. I have done about 30 AG BIAB Brews. I wanted to use this method to get used to everything before switching to a 3v system. I like the beer I make (and so do my friends) so I dont see the point in investing more. Bottom line, you can make very decent beer with BIAB (as you probably know already). Another trick I use is to use a stainless oven rack, put it over the pot and rest the bag on that. I gentry push the lid on it over the course of 5 min and get as much of the goodness out as I can. I suppose you could sparge this. I may try it for S&G's... I just see people rigging things up with their step ladders and fastening things to garage roofs etc and it's not required, as long as you can lift that bag out...

I have never done a mash out... Hmmmm. I just mash in, remove grain bag, heat to 212 and let er rip. Is this bad?

HopHeadGrady said:

II have never done a mash out... Hmmmm. I just mash in, remove grain bag, heat to 212 and let er rip. Is this bad?

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It's not bad. I never do a mash out and I do BIAB all the time. I did try it one time, and didn't see much of a difference to bother with it.

I think I'll experiment a bit as someone suggested
I need to get used to my new burner and 40 quart pot anyway
I know some people use calculators and I saw this one referenced online
http://www.brew365.com/mash_sparge_water_calculator.php
But I think it assumes there is a sparge and it's not necessarily specific for BIAB at full volume

But I plugged in numbers anyway

Variables
Batch size 5.5
Grain bill 10.25
Boil time 1
Trub loss 0.5 gallon
Equipment loss 1 gallon (default)
Mash thickness 1.33 quarts (default)
Grain temp 70 (default)
Target mash temp 152

Constants
Wort shrinkage 4% (default)
Grain absorption 0.08 (default was 0.13)
Percent boiloff per hour 10

Results
Total water needed 8.76 gallon
Mash water needed 3.41 galloon
Sparge water needed 5.36 gallon
Strike temperature 164.3
Pre boil wort produced 6.94 gallon

So if I'm aiming for 5.5 gallons of wort at the end, I'm assuming if I don't sparge, I just go with around 8.76 gallons for full volume boils

I know this isn't an exact science and there's a fair amount of experimentation, but this looks like a good ballpark figure to start with, unless you guys think that some of the variables are too high

If there is a better BIAB full volume calculator, that seems to be more accurate in your experience, can you point me to a link

Again Im not an expert at this by any means but that sure seems like alot to me. Your going to have to lose 3+ gallons of water between grain absorption and boil off and I just dont see it. I think you want to be closer to 6.5 gallons.

However, if you do end up with too much you can always just increase your boil time to get down to the right volumes. Your going to want to make that call before your late hop additions though or youll end up turning your flavoring and aroma into bittering.

Thanks trout and everyone else. 8.76 does sound like a lot
I'm going to do a test run on a 60 min boil of some water and see how much is lost
If I assume for now it's a gallon and grain absorption is about 0.5 gallon, then I'll start with 7 to end up with 5.5 after the boil

Probably a good estimate - I'd suggest boiling 7 gallons then when you test the theory. Also, if you haven't already done so, make a measuring stick while you're at it (add a gallon, insert your "stick" and mark the line, repeat until your done filling it.)

Great tip. Thanks for that

the_trout said:

Again Im not an expert at this by any means but that sure seems like alot to me. Your going to have to lose 3+ gallons of water between grain absorption and boil off and I just dont see it. I think you want to be closer to 6.5 gallons.

However, if you do end up with too much you can always just increase your boil time to get down to the right volumes. Your going to want to make that call before your late hop additions though or youll end up turning your flavoring and aroma into bittering.

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When it comes to my experience with BIAB, it's pretty bang on. There will also be loss because of trub on the bottom of the kettle and loss during fermentation. This is one thing that surprised me when I started BIAB.... the amount of water needed...

I usually mash with 4.5-5.5 gallons for grain bills between 9 and 13 lbs (2 to 1.7 qts/lb). You see higher efficiencies with the more dilute mashes. I have done tests on my system and see a 5-10% bump in efficiency when doing a mashout to 170. It's basically free anyway, you have to heat the wort so why not keep the grain in there a little longer. I doubt it changes the heating time significantly.

I also try to do some type of sparge. Usually just suspend the grains in the basket from rope/pulley and drip sparge as the wort is coming up towards boiling. Again not really any extra time, just the hassle of heating a second vessel on the stove to 175F. That sparge brings me up to pre-boil volumes and does contribute another 5% (on my system). I do admit skipping the sparge would make brew days a little easier. Lastly I squeeze the heck out of the bag with a saucepan lid against the basket.

I found a great calculator specifically for biab and have used it a few times. Simplebiabcalculator.com. good luck

/\ Im going to have to give this a shot to see how bang on it is. Its getting warmer for a few days this week, perfect for a garage brew session.

I brewed a porter on Sunday using that calculator and got 84% efficiency. I had too boil an extra 30 minutes, but that's ok with me for those numbers!

jokomobo said:

I brewed a porter on Sunday using that calculator and got 84% efficiency. I had too boil an extra 30 minutes, but that's ok with me for those numbers!

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What the h...I brewed a porter on Sunday and got the same efficiency. Are you like my doppleganger or from an alternate universe or something? Weird...