Batch size expectations?

[drummerguy]

With any luck, I will be receiving the Dark Star burner/8 gallon Tall Boy combo for Christmas. I want to keep doing 5 gallon batches, but I also want to make the move towards all-grain brewing. Given my current living arrangement, BIAB seems to be the easiest way for me to do this.

Using the BIAB method, what size batch would I be able to brew in an 8 gallon kettle? Would I be better off starting with a partial mash until I can get a larger kettle?

 

[LLBeanJ]

5g batches in an 8g kettle are doable. You may need to incorporate a small (1-2g or so) sparge for larger grain bills or boils longer than 60 min.

 

[dkennedy]

I ran a 7.5 gallon turkey fryer for a couple years, and was able to get 5 gallon batches of 'normal' weight beers easily. "Easily" might have involved overflow a few times, but I would think that you should be able to get 5 gallons comfortably with squeezing and sparging to make up the difference.

 

[drummerguy]

This is great news. I was afraid the kettle was going to be too small for what I was hoping to do. I've done a little bit of reading, but I figured I would ask this anyway. What should I shoot for as a starting volume for a 5 gallon batch?

 

[wilserbrewer]

An 8 gallon pot is certainly large enough for a five gallon batch...I would advise the ten gallon if possible.

$20 more for the 10 gallon is a good choice IMO.

 

[TexasWine]

What should I shoot for as a starting volume for a 5 gallon batch?

I'm going to make an assumption that by starting volume you're referring to the volume in the kettle before you start the boil and also that you want 5 gallons of beer at the end of the day. You probably don't want to hear this, but the answer is "It depends."

The reason I say this is because it depends on your boil off rate, the amount you lose in the kettle, and the amount you lose during the bottling/kegging process. It will be dependent on your system and processes, and even to some extent on things like the yeast you choose (flocculation).

So with all that, here's what I do on my system. I start my boil with 7-7.5 gallons, depending on the boil length. I end my boil with 6 gallons. I dump everything into the fermenter, trub and all. When I go to package, I leave 1 gallon behind and end up with 5 gallons.

Just as an fyi, I've been experimenting with shorter boils and things are working pretty good. The advantage for you in doing this would be that it reduces the pre boil volume.

 

[dkevinb]

I do BIAB in an 8-gallon kettle. I start with 6.5 gallons of water. That puts me within about 1/2 inch of the rim when I mash in 10-11 pounds of grain. I sparge by pouring another gallon of water through the bag, then squeeze it. This brings me back to about 6.5 gallons preboil. I typically boil off about 1.5 gallons. I dump 5 gallons into the fermenter and wind up packaging about 4.5 gallons.

I could probably add another half gallon to the sparge, then whirlpool before siphoning to the fermenter to have less trub in the fermenter and package a bit more if I wanted to. A 10-gallon kettle would make life easier, but then I'd also need a new bag and IWC. Heck, if 10 gallons is good, 15 gallons is better, right? But if I got a 20-gallon kettle I could do 10-gallon batches. But if 20 gallons is good, a 1-barrel system would be even better, right?

 

[wildactbrewer]

I am currently running 3 gallon batches with a 5 gallon kettle BIAB. These aren't huge grain bills by any means. I mash like normal and place the bag on a strainer over my kettle. I then pour 170F water through it and press on it with the lid until I can see the wort coming off clear below. I've had no problem hitting my target gravities and sometimes can even get up to 1.065 depending on the style.

I wouldn't think 5 gallons out of an 8 gallon kettle would be a big issue, assuming you don't have a crazy boil off rate. If you wanted to go big on a beer I would suggest a partial mash.

 

[ScrewyBrewer]

With any luck, I will be receiving the Dark Star burner/8 gallon Tall Boy combo for Christmas. I want to keep doing 5 gallon batches, but I also want to make the move towards all-grain brewing. Given my current living arrangement, BIAB seems to be the easiest way for me to do this.

Using the BIAB method, what size batch would I be able to brew in an 8 gallon kettle? Would I be better off starting with a partial mash until I can get a larger kettle?

12 pounds of grain and a 2.0 mash thickness takes up 7 gallons which should get you through the mash. Lift out the grains and sparge or add more strike water to hit 6.5-7 gallons preboil, depending on your boil off rate. So I guess it depends on the amount of grains you're planning to mash.

 

[wilserbrewer]

I find it tricky to get a 1/2 keg batch out of a 20 gallon kettle...can be done but you need to sparge, then start the boil up near the rim....

 

[Brew_G]

I have a 9-gallon pot and I just did a full volume mash on 11.25 lbs of grain whose "full volume" had about 1/2 gallon too much strike water. I'd imagine you'd be cutting it close, but you could probably do 10.25 lbs of grain in a full mash. If you wanted a larger grain bill, just decrease the amount of strike water and account for the difference by sparging to meet your pre-boil volume. You should be able to do a full volume boil with no problems. Just be sure to be on the lookout for boilovers as the boil starts.

 

[Black Island Brewer]

I love this thread! It really shows off the flexibility of BIAB, with regards to mash & boil volumes, boil off rates and times, post size. Once you have your hardware, there are many ways to accomplish what you want.

For ease, I like doing a full volume mash with no sparge or top offs, and I have a 10 gallon pot, so I'm limited to about 13 pounds of grain when I account for losses. But I can go with bigger grain bills if I don't do a full-volume mash and then sparge or top off. Great way to brew!

That said, were I do do it all again, I'd get a 15 gallon pot, for higher gravity full-volume mashes, or 10 gallon sparge/top-off batches.

 

[Brew_G]

I love this thread! It really shows off the flexibility of BIAB, with regards to mash & boil volumes, boil off rates and times, post size. Once you have your hardware, there are many ways to accomplish what you want.

For ease, I like doing a full volume mash with no sparge or top offs, and I have a 10 gallon pot, so I'm limited to about 13 pounds of grain when I account for losses. But I can go with bigger grain bills if I don't do a full-volume mash and then sparge or top off. Great way to brew!

That said, were I do do it all again, I'd get a 15 gallon pot, for higher gravity full-volume mashes, or 10 gallon sparge/top-off batches.

Bingo! There are plenty of ways to get where you want to be. Stovetop brewing limits my pot size, but the 9-gallon pot works perfectly for both my process and my needs.

 

[kh54s10]

Another way to state this is: There are different ways to get the wort needed for your boil when doing BIAB. No sparge would mean you have enough wort when removing the grain for your boil. Or mashing with a certain amount then sparging with more water to attain you preboil amount.

Your preboil amount will need to be fine tuned. Some burner/kettle combinations will only boil off about 1/2 gallon per hour, mine is almost 2 gallons per hour. You can test with a pot of water or estimate then refine over a few batches.

The pot size you are getting is a bit on the small size for 5 gallon batches, but if you watch carefully at the start of the boil it is big enough. I among many others got the turkey fryer pot as a start for full boils, at 30 qts it is close to the top at the start and boil overs are easy if you don't watch and control the heat until some of the water boils away. Make sure you are on a surface that you can hose off after the brew.

I have a 10 gallon pot now and brew on my porch that has a carpet. It is quite stained!!!

 

[drummerguy]

I would like to thank everyone for the responses. I'm actually quite surprised I got as many as I did. I do wish I could get the 10 gallon kettle, but I'm not sure I can justify the cost at this time; the burner/kettle combo is only $119. However, after reading the responses in this thread, I am really excited to get started with BIAB. I guess it will just take some experimentation to see what I can accomplish with the equipment I will (hopefully) have.