BIAB bag sparge

Might be talking about needing a ten gallon pot to do a full boil for a 5 gallon batch....you would be boiling 6+ gallons of worth. Hence the need for a larger pot. I have a 7.5 gallon pot and it is barely big enough for a full boil, would be much more comfortable with a 10 gallon pot.

I do full boils just fine with a 30 qt pot. You can keep a boil pretty close to the top with fermcap and not blasting your burner. I usually do 6.75 gallon boils. Just turn the heat down as you approach boil.

I too MiaB (Mash in a Bag).. pretty much exactly like some others do.

I mash at 156F for 90 minutes, the put the bag in my BK which has 2 or 3 gallons of 170F water for 10-15 minutes, "teabag" it to get things good and churned up, then lift it out and place it on a stainless colander that goes over my BK. While that is dripping, I run the super-sweet liquor from my Igloo cooler (I think it's actually a Coleman, but it's blue, which works better than the orange ones).

Once the MLT is empty, I "top off" my BK by pouring 170F water over the bag of grains.

I have no clue what my efficiency is, and honestly don't care. My beer is coming out consistently good.

houndsbreath said:

Allright, I need opinions on this 5 gal batch. Basically, I'm concerned about volume.

My Recipe: 12 lbs grain done BIAB
My Largest pot: 24 qts (6 gallons)
If I mash 12 lbs grain with 1.5 qts/lb, that makes 4.5 gallons + 0.7 gallons for grain (according to this calculator Green Bay Rackers) so my total volume will be 5.2 gallons. This seems low considering 12 lbs is ALOT of grain.
I'll mash at 165F for 1 hour, then sparge at 170F for 10 min in a cooler.

Concern: Why do I hear talk about needing a 10gal pots to make a 5 gal batch. Is my math wrong or did I miss something??

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if you were doing a standard BIAB you would be using full volumes of water (no sparging). to determine the amount of water it would be desired batch + grain absorption + boil off +trub loss. As you can see, you quickly approach volumes greater than your 6 gallon pot. for my setup, with 12lbs of grain I would be starting with 8 gallons of water with a 5.5 gallon volume going into the primary. Add in the .7 gallons for grain and we're approaching the 9 gallon mark

Thanks for the clarification. I'm shooting for 75% efficiency with 4.5 gallons plus ~2 gal sparge.
This calculator helped me get my head around the concepts here.
http://www.brew365.com/mash_sparge_water_calculator.php

houndsbreath said:

Thanks for the clarification. I'm shooting for 75% efficiency with 4.5 gallons plus ~2 gal sparge.

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first shoot for making great beer.. then work on the numbers. that said, double crush the grains and you'll hit 75%.. or better

quick question on biab. i have a 32 quart boiling kettle, which i presume won't give me enough room for the water and grains (including grain absorbtion and assuming some higher gravity beers) needed to end up with a 5 gallon post boil volume (assuming i need roughly a 6.5-7 gallon pre-boil volume). i've haven't done the math (if somebody knows any rules of thumb, please let me know), but for example sake, say i biab with 6 gallons (or whatever will fit) along with the grain bag, and then i drain the bag and that leaves me around 5 gallons (assuming 1 gallon for grain absorbtion). Can I just throw the bag into my bottling bucket that has 2 gallons of sparge water that I've heated separately, tea bag it, sit for 15 minutes and then pour the wort from the bottling bucket (roughly 2 gallons) into the kettle, leaving me with my 7 gallons of pre-boil volume?

i want to step up to AG without having to buy new equipment (in this case including a larger BK).

newtobrew5 said:

Can I just .....................

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Yes you can

jjones17 said:

No, not the mash. I am talking about the sparge. I would take the time to get 3 or 4 sources of the 60 minute sparge, but I am lazy. A google search for "60 minute sparge" finds several bits of info suggesting 60 minutes is optimal. This may be referring to the flow of your sparge, and how it should take 60 minutes to drain from the MLT so your sparge does not get stuck. Could be wrong, sounds like I am the only one who is concerned about it

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Know it's an old thread, but just felt this needed a reply. This definitely refers to fly/continuous sparging and not BIAB. As you say, with fly sparging they have to avoid compacting the grain bed and ensure an even flow of water. With BIAB you just stir it all in for 20 minutes and lift it out, and that gets you most of the sugar you could possibly get.

For the sake of a few gravity points I personally don't understand why anyone would opt for fly sparging over batch(/BIAB) sparging. I think a few folks just like to make the process complicated so they can build an impressive system, complete with sprinklers and all.