Cheating a full volume BIAB for smaller vessel

[Craig Bird]

Hey all, I am designing my ebiab setup and really want to use the GigaWort system. This is a 4.4 gal system. I want to brew 3 gallon batches and my typical grain bill would be under 7 lbs. Anything bigger than that and I would do a smaller batch. Throwing that into the BIAB calculator gives me a mash volume of 5.75. What process changes can I make to allow me to use this vessel with BIAB for 3 gallon batch? I am going to BIAB for time savings, but looking for that middle ground that may add a bit of time but still save time compared to traditional all grain brewing.

 

[ATLBeer]

Something is off with your calculator. Using a standard of 1.25 - 1.5 qts/lb., a 7lb bill would max out about 2 1/5 gallons or so.

Am I missing something?

 

[DBhomebrew]

Move some water into a sparge step. Or, figure your max grain bill and get the rest of your sugars via extract. The extract would replace some base malt so make sure your mash still has enough enzymes.

 

[Craig Bird]

I was just using the Brew in a Bag (BIAB) Calculator ~ You need to consider boil off and grain absorption correct?

 

[Craig Bird]

Something is off with your calculator. Using a standard of 1.25 - 1.5 qts/lb., a 7lb bill would max out about 2 1/5 gallons or so.

Am I missing something?

I was just using the Brew in a Bag (BIAB) Calculator ~ You need to consider boil off and grain absorption correct?

 

[ATLBeer]

nothing boils of during mash, that variable may be for full volume mashing?

I use 1.25/1.5 to mash then add sparge water in my all-in-1 to get to my pre boil target. I can get 16 lbs+ in my robobrew pot and its not even close to the top.

 

[Craig Bird]

This thread response came up as a suggestion under my post:

A 4.5 gallon brew pot can do big things with a few work arounds such as sparging and topping up both during and after the boil.

Batch or dunk sparging your grain bag in a bucket of ambient temp water is pretty easy and will greatly increase your pre boil amount of wort. Topping up the kettle as you boil off, say for the first 1/2 of the boil will also help.

I’d guess you could get as far as 5 gallons mid gravity batch w a few “tricks”

 

[Craig Bird]

nothing boils of during mash, that variable may be for full volume mashing?

I use 1.25/1.5 to mash then add sparge water in my all-in-1 to get to my pre boil target. I can get 16 lbs+ in my robobrew pot and its not even close to the top.

I was assuming I would do full volume and increase the temp of the GigaWort at the end of the mash to stop conversion. I am coming from traditional 5 gallon batch sparge brewing so perhaps I do not know the options well enough for biab.

 

[ATLBeer]

I had to look up your equipment to understand what's going on. one difference is the lack of a grain pipe that lifts out and allows the mash to drain back into the pot, I sparge at that point, getting to by pre boil volume.

You need to use a bag, which is fine, but you will want to sit it on a strainer or something to let it drain at mash out. You could pour over sparge water as well. I think that's fly sparging?

Regardless, you are over estimating the mash volume. On your first batch, start with just under 3 gallons and have additional hot water ready. you can top off with more if you have room. Adjust on your second batch.

 

[madscientist451]

Hey all, I am designing my ebiab setup and really want to use the GigaWort system. This is a 4.4 gal system. I want to brew 3 gallon batches and my typical grain bill would be under 7 lbs.

The rated capacity of the kettle is 4.4 gallons. Sure, you can do 3 gallon batches, but you'll have to add water when you transfer to the fermenter to hit that volume.
My rules of thumb for volume:
3 gallon batch
3 gallons of beer, 1 gallon of evaporation, 1 gallon of absorption/trub, means you'll need to start with 5 gallons of water, so that isn't going to fit in a 4.4 gallon kettle. You'll have to do a boil test to see what your evaporation rate is. Your absorption volume will vary depending on how much grain you use, so you'll have to factor that in. I like to leave about 1/2 gallon hops/trub in the kettle, but some brewers add the whole thing to the fermenter, so your preference will have an effect on volume.
If you reduce your batch size to 2.5 gallons, you may be able to do it with that equipment. I'd figure on having a cheap 12-16 quart side pot to do a dunk sparge in after you pull the bag, then combine everything.

 

[doug293cz]

I was assuming I would do full volume and increase the temp of the GigaWort at the end of the mash to stop conversion. I am coming from traditional 5 gallon batch sparge brewing so perhaps I do not know the options well enough for biab.

Your vessel is not large enough to do a full volume mash. You will need to mash with a fraction of your water (50 - 60%) and then sparge to make up the rest of your pre-boil volume. You can do a pour over sparge with the grain bag in a colander (or similar), or you can do a dunk sparge by just placing the grain bag in a bucket with the sparge water (doesn't matter if it's hot or cold sparge water.) Sparging will improve your mash efficiency. A dunk sparge will be more consistent than a pour over sparge.

Brew on

 

[bwible]

The rated capacity of the kettle is 4.4 gallons. Sure, you can do 3 gallon batches, but you'll have to add water when you transfer to the fermenter to hit that volume.
My rules of thumb for volume:
3 gallon batch
3 gallons of beer, 1 gallon of evaporation, 1 gallon of absorption/trub, means you'll need to start with 5 gallons of water, so that isn't going to fit in a 4.4 gallon kettle. You'll have to do a boil test to see what your evaporation rate is. Your absorption volume will vary depending on how much grain you use, so you'll have to factor that in. I like to leave about 1/2 gallon hops/trub in the kettle, but some brewers add the whole thing to the fermenter, so your preference will have an effect on volume.
If you reduce your batch size to 2.5 gallons, you may be able to do it with that equipment. I'd figure on having a cheap 12-16 quart side pot to do a dunk sparge in after you pull the bag, then combine everything.

I calculate all my ‘3 gallon’ recipes to collect 4 gallons and boil down to 3.5 gallons so that i will actually get 3 to 3.25 gallons of “clean” wort into the fermenter. From there you will have additional losses to yeast waste and other waste that settles out in the fermenter. With the method I’m using I just about always get 30 bottles if I’m bottling (12 oz) or a full 3 gallon keg at the end.

I have an Anvil 5 gallon pot. It’s heavy duty. The one thing I didn’t like is that it comes with a thermometer which has a pretty long probe and there is no option to get it without the thermometer. The thermometer interfered with my wort chiller and it would be a problem using a brew bag. I took off the thermometer and filled the hole with a plug Blichmann makes. Works like a champ and I really like the pot now.