3-Gallon BIAB Questions on Grain Bill & Water

[JoefromPhilly]

I want to try BIAB, but want to do 3 gallon batches. I have read a lot about how people do this in different ways, including mashing with only part of the water, then using the rest to "dunk" and rinse the grains. Here are my questions:

What is an effective way to do this? Is it to bring all the water to the 156 degree range, mash for an hour, then raise the temp to 170 for 10 minutes, or do a two step process?

What is the best way to determine how many pounds of base malt to use for whatever style of beer I want to brew? Do I just take the grain bill for a 5 gallon batch and multiply by three-fifths?

How much water will be retained by the grains?

This leads up to my last question - How much water should I start with

I tried to get these answers on my own first, but have not found any consistent info.

Thanks,

 

[chickypad]

The total volume of water you need is going to be the volume you want in the fermenter less your boil off, loss to grain, cooling loss, and losses to kettle trub. For my 3 gal BIAB batches I need about 4.5 gal of water to get a full 3 gal in the fermeneter. I do squeeze the bag, and find grain absorption to be about .075g/lb of grain as opposed to the .125g/lb I lose when using a regular tun.

If your efficiency is the same as the recipe then yes, you can just multiply a 5 gal recipe by 3/5 to get the grainbill.

As far as how you want to hit your temps, and if you want to sparge vs. full volume mash it's a lot of personal preference and tailoring your own system. I find for the average 6-7 lb grainbill I can't quite fit the full volume mash in my 5 gal pot, so instead I'll mash with around 3 gal then dunk sparge in 1.5 gal of 170* water. I don't like direct heating the kettle with the bag in there so I heat the strike water first then add the bag and grains. To hold the temp I like putting the pot in the oven, I preheat to 170 then turn it off. I don't really see the utility of a mash out with BIAB.

Lots of ways to skin a cat, that's just my particular process.

 

[JoefromPhilly]

Thanks. That will be my next brew. I just kegged my Alaskan Amber today. That batch was strange, because after a full month in the primary, I transferred to a secondary and added hops. The brew fermented for a full week, with visible bubbles each day. The FG dropped a bit more, down to 1.012. I poured a glass of what did not get siphoned out, and the taste was great. I did not realize that there is enough CO2 in the non-carbonated beer to not have the feeling that you are drinking flat beer.

- Joe

 

[mikebanyai]

Each of us does this a bit different and most all get to a good end. This is how I do three gallon batches in a 5 gal pot. I love the 3 gal bit, enough but not too much beer, can make a bunch of smaller batches. Measure out 3 gal, then mark or scibe your pot to this, also 3.5,4,4.5. I start with 3 gal and have no problem geting the grain to fit, for ease of use I also use 2 seperate bags, but many use one. I take the water to the mid 150's, a bit more or less depending on style, add grain and let it hang out for the hour or so, although truly I respect the fellow who questions why we do more time then needed as proven by starch conversion, many parts of brewing are dogmatic, caus I always do it, a digression. A couple of times during the hour I lift the bags a bit, stir things a bit, not critiical. Then I set the bags in a colander over a different pot, and note the water level of the wort, will be more then 2 but less then 3 gal most likely. I then pour some water over the bags a quart at a time and add the drippings back to the pot. I quit when I get back to the 3 gal mark. You can do an opening gravity then to see the ballpark figure. If weak, add some DME, if too strong go for it or if picky, take some wort and replace with water. Now with personal preference and or experiance you can add more water for the boil, generally I begin boil at 3.5 gal or a bit more, if it gets low you can always top it back to the 3 gal mark. At the end of the hour boil you are back at the 3 gal mark and rock and roll forward from there..just my way, it works for me, not better or worse then any other way. Most of the time I can do it all in 3 hrs, sometimes less. I get in the low 80's conversion most batches..

 

[Ilan34]

The total volume of water you need is going to be the volume you want in the fermenter less your boil off, loss to grain, cooling loss, and losses to kettle trub. For my 3 gal BIAB batches I need about 4.5 gal of water to get a full 3 gal in the fermeneter. I do squeeze the bag, and find grain absorption to be about .075g/lb of grain as opposed to the .125g/lb I lose when using a regular tun.

If your efficiency is the same as the recipe then yes, you can just multiply a 5 gal recipe by 3/5 to get the grainbill.

As far as how you want to hit your temps, and if you want to sparge vs. full volume mash it's a lot of personal preference and tailoring your own system. I find for the average 6-7 lb grainbill I can't quite fit the full volume mash in my 5 gal pot, so instead I'll mash with around 3 gal then dunk sparge in 1.5 gal of 170* water. I don't like direct heating the kettle with the bag in there so I heat the strike water first then add the bag and grains. To hold the temp I like putting the pot in the oven, I preheat to 170 then turn it off. I don't really see the utility of a mash out with BIAB.

Lots of ways to skin a cat, that's just my particular process.

This is extremely similar to my process: kettle size, preheated oven and all. Except I split the boil into two 2.5 gallon pots. Works great!