Brew in a bag small batches. extra grain?

Hi,

I'm thinking of diving into all-grain (after having done several mini-mash kits) by getting a "regular" all grain kit and dividing it into 2 batches and doing brew-in-a-bag method. It was suggested to me that because this method might have less efficiency, it might be wise to add some extra grain to make up for it. My question is: How much grain for, say, a 2 1/2 gallon batch with roughly 5lbs of grains? (just thinking of a typical kit)

And would it be base grains added or a little bit of base and specialty grains? The type might be subjective but I was wondering if anyone had an idea of the quantity of extra I might add to try to get the efficiency up. Probably not an exact science.

Thanks!

Don't add extra specialty grains. Add about 10% more base grain and you'll be fine. Honestly though if you crush the grains finer you really should be fine. I brew both BIAB and traditional all grain and I consistently get better extraction with BIAB. If you can't crush finer, crush twice. I think you'll find it comes out just like I supposed to.

It depends on your set up. I BIAB 5gallons and 1 gallon test batches. I made one 2 gallon test batch to have enough wort to use hydrometer on and my efficiency is about the same. Therefore I just 1/5th any recipe that sounds interesting but not interesting enough for 5 gallons yet.

Whats weird is that my 1 gallon batches are tasting much better than 5 gallon batches. I think easier temperature control on mash and the ease in cooling wort in 1 gallon batches to ferm. temps is the reason. Need to work on my immersion chiller or see if Santa will get me a Blickman plate chiller.

I do small batches because I can do them in the kitchen easy as opposed to taking 6 hours to do a complete AG brew. My biggest problem is figuring out the hop amount in a smaller amount as my scale doesn;t show less than 1/2 ounce. Also remember to account for volume loss in smaller batches...it becomes more critical in a smaller amount. I don't like to add top off water after the boil, I like the idea of boiling everything that goes into the fermenter. I do 1 gallon batches often and have a 2 gallon MLT made from a small Coleman round cooler.

I don't think you will get less efficiency from smaller mashes. Squeeze the bag and rinse more sugars out by drizzling some sparge water and squeezing again. I consistently got great efficiency with biab. The cooler gets good efficiency as well, but it is slightly lower.

Thanks for the responses. I think I might just try dividing it in half and seeing what happens just to get a baseline efficiency. Then when I do the second "half" I might add grains and measure again. How much wort would you all say evaporates off during the boil? For a 2 1/2 gallon batch, how much should I start with so I don't have to add much or any top-off water at the end? I'm guessing I would need a little more than 3 gallons to start the boil.

Thanks again!

vadem said:

How much wort would you all say evaporates off during the boil?

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My 4gal pot boils off .875gal per hour. I've calculated it out though that's how I know. I would assume if you start about 1gal higher than your final volume you should be close.

If you want to conduct an evaporation test, you'll have a closer idea of your rate. Just get 2 or 3 (preferably 3 since that's your boil size, or close to it). Then set the timer for 60 minutes once the boil starts and take a measurement after the boil is over. Remember too that water expands as it's temperature rises and contracts as the temperature drops. Your volume of water just after you turn the heat off will be about 4% more than when it's chilled to pitching temps.

The other thing to factor is the amount that evaporates off while your heating the water up to boiling. All these tests and measurements are by no means necessary, it's part of dialing in your system though. Good luck!