BIAB in small pot low water volume"?

[Ahhh-smooth]

I am confused why all the BIAB instructions talk about full boil volume being used (e.g. like 7 gallons for 5gal batch). In normal infusion mashing I always see that 1qt per lb of grain is sufficient - then of course the additional sparging water is added.

Can't I continue to use 1qt to 1lb of grain (so it fits in my pot) and add cold water later in fermenter like I have always done?

I know efficiency is a question, but normal infusion works with the low volume of water.

Thanks. Trying to avoid another new pot.

 

[wattershed]

It's a matter of real estate for the grain to fully extract. You only do a partial volume mash with a "normal" 3-tier process because you make up for the rest of it in the sparge. If you use, say, 60% of your final volume in the mash, the grain will release only so much sugar, needing to be rinsed (sparged) with the other 40% to get to a good efficiency point.

Since you're not sparging with BIAB, you need to give the grain more real estate (water) to convert. If you take the approach you're hypothesizing, you're going to get poor conversion of the sugars topped off with a dilution with the top-off h2o.

To put it another way, let's say you have a 3-gallon pot. if you BIAB with 2 gallons mash water, you wouldn't want to top off with 3 gallons, would you? Or, how about one gallon of water in a 10-gallon pot with your whole grain bill, adding in 4 gallons h2o later?

 

[Riot]

You can definitely do a traditional volume mash with BIAB, you just sparge to preboil volume like you would with a mash tun. I've done over a dozen batches this way, I've never done a full volume mash. I feel like PH would be a nightmare with that much water.

 

[Riot]

I just reread and saw you where talking about a smaller volume mash and an after boil top up. That won't work nearly as well, efficiency will be very poor.

 

[Ahhh-smooth]

Thanks guys. I was not taking into account the sparging step which is not done in BIAB. I may try a few though to see how much I miss the OG for a designed recipe. Also, I may start adding more sugar as adjunct and see.

 

[Riot]

It's pretty easy to sparge in a bucket, you can even use cold water pretty effectively

 

[kh54s10]

You can do a BIAB and then use top up water but you will have to make adjustments for that. Most recipes call for full volume boil. Thus you have the proper preboil gravity to end up with the right OG. If you are using the top up water you will have to make your preboil gravity higher so that when you top up you will end up with the right OG.

If you just add sugar to increase the gravity you will make a thin beer with less taste than if you scale it properly.

 

[Ahhh-smooth]

I think what I will try is following..
For 10lbs grain and 5 gallon batch (limited to 5.5 gallon pot); do the BIAB mash in 2.5 gallons of water; then heat another 2.5 gallons in another pot at 170 deg; move the bag to the second pot for some period of time; then combine the two worts into the original pot and boil. That gives me the 5 gal boil I can handle

I realize the water ratio is off, but maybe the clean sparge in the second pot will help

Think this will work? Thanks.

 

[christpuncher123]

I think what I will try is following..
For 10lbs grain and 5 gallon batch (limited to 5.5 gallon pot); do the BIAB mash in 2.5 gallons of water; then heat another 2.5 gallons in another pot at 170 deg; move the bag to the second pot for some period of time; then combine the two worts into the original pot and boil. That gives me the 5 gal boil I can handle

I realize the water ratio is off, but maybe the clean sparge in the second pot will help

Think this will work? Thanks.

I have never noticed a difference in efficiency by sparging in another pot. In the winter when I brew inside in a smaller pot I just put as much in my pot as I can and then top up with cold water. Once I hit my 5.5 gallon mark my og is usually bang on. There is also no noticeable taste difference between my full boils in the keggle in the summer and the partial boils in the winter.

 

[calvey]

Use this to figure out how much grain and water you can fit in your mash: http://biabcalculator.com