Partial Mash BIAB Full Boil

[wherestheyeast]

I have the Cascade Pale Ale Partial Mash kit from Midwest that I'd like to brew tonight. The directions have you mashing 4 lbs of grain in 1 gal of 151-154F water for 45-75 minutes. Then sparging with 1.5 gals of 175F water through the grains into the boil kettle, add the 3.3 lbs LME & bring to boil adding hops as directed. After cooling I'm to add this wort to 3.5 to 4 gallons of cold water, pitch the yeast, etc., etc.

I'm wondering if I can make this beer by using a single-vessel BIAB method:

* I'd mash the 4# of grain in ~6 gallons of 151-154F water for 60 min
* Pull the bag & dunk a couple of times in the wort; allow to drain into BK
* Add the LME while letting the bag drain, bring to a boil & follow the hopping schedule.

Any reason not to do it this way? Also, do I need to adjust the hop additions since the directions are for a partial boil?

 

[BPal75]

You can do no sparge but you'll like get lower efficiency. The rinsing of the grain, whether by running sparge water over the grains suspended over your kettle (modified fly sparge) or dunking your Bag of grains in a second kettle of sparge water (modified batch sparge) helps extract more sugar from the grains and ups your efficiency, meaning you'll get a higher OG for your given grain bill.

I would not use 6 gallons of water to 4 lbs grain. You want to keep your water to grist ratio around 2 quarts per pound of grain for BiAB, so use about 2 gallons of water for mashing.

You don't need to adjust your hop schedule.

 

[wherestheyeast]

I thought I heard/read somewhere that BIAB can be as much as 4 quarts/pound of grain. In any case, I now realize that 6 gals/4lbs is closer to 6:1.

The reason I ask, is because I only have a 2gal pot & a 10gal pot; is it possible to do this Partial Mash as a full-volume boil with what I have. If so, how would I go about doing that?

-WTY

 

[chickypad]

How wide is your 10g pot? Meaning, if you put in 2 gallons will it be enough to cover the grain bag? If so you could mash in there then either dunk the bag in the second pot to sparge with as much water as will fit, or put the bag in a colander over the 10g pot and pour the sparge water from the 2g pot over it. Alternatively you could mash with a smaller volume in your 2g pot and sparge in the brew kettle.

DeathBrewer has a nice sticky here if you haven't seen it.

 

[BPal75]

Given your setup and your recipe, if it were me I'd mash in the 10 gallon pot and then put your bag in a colander over the pot and sparge with water from your 2 gallon pot. Then I would refill your 2 gallon pot, heat your new sparge water, repeat. It will take awhile to repeat but you'll get more sugars out. I know many ppl will do several batch sparges, so it's not too much different a concept as that.

If you're more concerned about time then money, you could always increase your grains since you have a large pot big enough to hold more, then go no sparge or only sparge the one time and be done with it. Using software like beersmith will help you tweak how much grain you'll need for a given efficiency to help you hit the same OG.

Good luck!

 

[ShackNasty]

DeathBrewer has a nice sticky here if you haven't seen it.

This!!!!!
It's a very informative sticky and sounds like it could be of use to you.

 

[wherestheyeast]

The 10g pot is about 15" wide. I'm not sure if 2 gals would cover... Hmmm.

Either way, I'm still a bit confused on how to handle this while also doing a full-volume boil.

I've studied DeathBrewer's sticky to death (no pun). And I get it if I was doing a partial-boil with two pots larger than 2 gals. I'm having a hard time figuring out how to use my set up while doing a full-boil (if possible).

I know I tend to make things overly complicated! Buuuttt, if I mash with 1 gallon of water in my 2 gallon pot, then dunk sparge in the brew kettle, what volume should be in the brew kettle? Would it be something like: Dunk-Sparge volume = pre-boil volume - mash volume?

Or, should I just forget about trying to do a full-boil batch?

 

[chickypad]

In my opinion you should always do a full boil if you have the space. But I think you're right, you're over complicating. Figure out what your pre-boil volume needs to be based on how much you want in the fermenter and how much you expect to boil off. Add your sparge water to the mash water in the kettle, then top off with however much water you need to reach your pre-boil volume.

 

[bobbrews]

Heat water in two kettles. One can be smaller than the other.

1st Kettle = 160-ish water to get you down to 150-ish mash temps. (1.5 liters per lb. of grain)
2nd Kettle = 175-ish water (for dunking your grain bag / mash out after mashing).

After the mash, drain the bag over the grain wort, then dunk several times in the plain mash out water. Let the residuals drain in a bowl on the side.

Continue with your boil as usual. Add LME at 15 minutes left in the boil.

 

[wherestheyeast]

Thanks to all for the input!

I've done some additional reading/searching and found a few other threads that seem relevant:

https://www.homebrewtalk.com/f39/partial-mash-but-full-boil-212503/
*** specifically Yoopers response to the OP***

and

https://www.homebrewtalk.com/f13/mash-ph-full-volume-no-sparge-mash-146961/
***some discussion on pH as related to grist ratio***

I'm a new(ish) homebrewer (and definitely no scientist), but I like to read a bit of the science behind the "truths" that are disseminated.