How much grain?

[WaltG]

So i keep seeing that if you're going no-sparge biab you can just add a bit of grain to make up the efficiency? How much grain? Like the one I'm getting ready to start has a grain bill of 13.5lbs, just add 10% to all the grains?

 

[beernut70]

I don't understand where this drop in efficiency comes into play. Once I switched to BIAB my efficiency went way up. I am adjusting my recipes for 80% now.

 

[WaltG]

do u sparge?

 

[beernut70]

Nope put all my water in the kettle then the grain. I usually start with around 7 1/2 gallons for a 5 / 5.5 gallon batch. I also squeeze the grains a lot don't leave anything behind. A good crush is important, I have a cheap corona mill. Once the mash is done I turn on the burner and stir or move the bag around until I get to around 170 then pull the bag put it on a grill rack over the kettle and squeeze everything out and continue to the boil. I use cheap PVC gloves from harbor freight to squeeze the bag.

 

[roastquake]

Crush your grains finer than you normally would, that is how a lot of BIABers make up for lost efficiency. I usually get about 75% without adding any extra grains

 

[RM-MN]

I've gotten 80% without any sparge step. If I include a small sparge just to rinse out a little more sugar I go over 85%. How much grains do you think I should add, 10% to make up for the loss in efficiency?

 

[WaltG]

In a 5 gallon batch I was thinking of sparging with just 1 gallon water just to get the excess out.

Never actually checked efficiency. Not even really sure what it is or how but i'm sure there's a calculator online.

 

[RM-MN]

I doubt that I sparge with much over a quart and that is cold water too. The grains are pretty hot and that heats up that little bit of water pretty well so it can absorb the sugars.

 

[1MadScientist]

So i keep seeing that if you're going no-sparge biab you can just add a bit of grain to make up the efficiency? How much grain? Like the one I'm getting ready to start has a grain bill of 13.5lbs, just add 10% to all the grains?

A full volume BIAB uses all the water needed at the beginning during the mash, when the bag is pulled, that is called a passive sparge. No other water is used after that. You are allowed to squeeze the bag all you like and add it to the kettle before the boil starts. No additional grain needs to be added for BIAB.

No-sparge has nothing to do with BIAB.

As a matter of interest, 13.5 pounds would produce a 1.065 OG with 9 gallons of water (2.75 qt/lb ratio).

 

[WaltG]

Don't worry about tannins if you squeeze out the bag?

 

[beernut70]

Don't worry about tannins if you squeeze out the bag?

No that's a myth. It's impossible for person to squeeze tannins out of the grain. If you have a smaller pot by squeezing the bag will let you get more out of your mash since your not losing as much to absorption.

 

[WaltG]

So I have a 32qt pot with a 13lb grain bill for a 5.5gal brew. Needless to say it's going to be a tight fit. How much water per LB does grain displace.

 

[Brewcycle69]

These should help...

https://www.homebrewtalk.com/f11/how-big-your-mash-tun-needs-123585/

https://www.homebrewtalk.com/f36/mlt-size-spreadsheet-can-i-mash-what-tun-should-i-get-443654/

Cheers

 

[TimelessCynic]

As a matter of interest, 13.5 pounds would produce a 1.065 OG with 9 gallons of water (2.75 qt/lb ratio).

13.5 pounds of DME maybe. Certainly not grains, unless you boiled that down to 6 gallons.

 

[Pkrd]

So I have a 32qt pot with a 13lb grain bill for a 5.5gal brew. Needless to say it's going to be a tight fit. How much water per LB does grain displace.

You don't have to use the full amount of water for the mash. Use as much as you can. Top up when you start the boil. Efficiency might take a little hit but grain is cheap, big pots are expensive.

 

[beernut70]

I use the spreadsheet below and it has been very accurate since I dialed it in. My absorption is set down to .05 but I squeeze the bag. Use as much water as you can then dunk the bag in whatever remaining water you need to hit your volume.

BIAB Spreadsheet

 

[TBaGZ]

13.5 pounds of DME maybe. Certainly not grains, unless you boiled that down to 6 gallons.

You wouldn't boil 9g down to 6g.. 9g is the starting volume and there is going to be absorption during the mash. You might have 7 or so after mashing to boil down. I easily get 1.065 with 13ish pounds of grain with around 8 1/2 to 9 gallons full volume mashing.

 

[TimelessCynic]

You wouldn't boil 9g down to 6g.. 9g is the starting volume and there is going to be absorption during the mash. You might have 7 or so after mashing to boil down. I easily get 1.065 with 13ish pounds of grain with around 8 1/2 to 9 gallons full volume mashing.

Are my calculations wrong? Just say grain gives 36 points per pound per gallon.

You have 13.5 pounds times 36 points divide that by 9 gallons and you get 54 points so 1.054 gravity. And that is at 100% mash efficiency.

Or are you guys talking about the post boil gravity of a 5.5 gal wort. In which case yes 13.5 lbs of grain is plenty to achieve 1.065

 

[TBaGZ]

Yes, post boil.

 

[ten80]

I achieved 87% efficiency on my last BIAB brew using re-circulation and stirring during the mash with a 3:1 grain to water ratio. That's 10% better than what I achieved with batch sparging. You'll have to try your system and see what it gives you, then use that percent efficiency for your next brew calculations.

Tannin extraction occurs when pH increases above the ideal mash range (5.2-5.6). This is often a problem during batch sparging as the wort is diluted by circumneutral pH sparge water, causing the pH to increase unless the sparge water is pre-acidified.

Assuming that your BIAB mash pH is in the ideal range at the beginning of your mash (if not, add acid), then it should remain stable regardless of whether you squeeze your grains, and tannin extraction is a non-issue. Mechanically disrupting the grains (i.e. squeezing) is not going to extract any more water soluble molecules (i.e. tannins or sugars) than would one hour of soaking in ~150 degree water. I love how BIAB greatly simplifies mash chemistry!