BIAB Partigyle, normal beer & baby beer

[Mike37]

I've been toying with the idea of doing this recently and I can't quite wrap my feeble brain around it.

What I want to do is brew a 5 gallon 1.050 stout and a 2 gallon "baby" beer for my light beer drinking guests.

My normal routine is a partial volume BIAB with a sparge to reach my boil volume. This has been working great for me so far.

I'm guessing to do get the baby beer, I would mash like usual, but put the bag over another pot and sparge into that instead to reach 3 gallons for the "small" beer. Then I would just dilute my "big" wort to 6 gallons with fresh water.

I think the main thing to note here is that I have no target gravity for the baby beer. It'll be very lightly hopped and served cold for the masses. I'm just looking to pull some color and flavor from the stout and hopefully some fernentables. Does this sound like it might work? Would my 1.050 stout suffer from no sparge?

 

[erikpete18]

The Brau Kaiser partigyle simulator might help you out. I'm planning to do a bigger version this weekend (RIS/dry stout) and the excel sheet helped me wrap my head around it a little better. Since it sounds like you're partial BIAB is closer to a standard mash (rather than the full volume BIAB), I don't see any reason why it shouldn't work out for you. As for your first stout, I'd read/heard one study where the non-sparged beers actually tasted better, so that should be good.

For the baby beer, you may want to make sure you've got some dry extract handy in case you wind up real low. Not sure if you've got any past readings for first runnings and sparge gravities, but when I was doing BIAB I'd crush a little finer, which might influence how much is left for the sparge to remove. Having the extract on hand allows you to toss a little in to get it up to a respectable range (1.03?).

 

[erikpete18]

Now that I think about it, I'm trying to see if I can figure out your process. I'm doing mine opposite of you, high gravity/small beer first, low gravity/big beer second. If you don't mash thin, you may want to plan on doing one sparge for the first beer, and a second for the small beer. With a ratio of 1.5 qt/lb, I generally get back around 2/3 of my strike water, so about 2gal of first runnings. You're going to have a hard time getting the first runnings high enough gravity at that ratio to dilute for 1.05 batch. You might already be mashing at a higher ratio, but I would think north of 3qt/lb is probably better, so you make sure to get the majority of the sugar out in the first batch.

Like I mentioned, the other option is to sparge once for the big beer, and just do a second sparge for the baby beer. The simulator I linked to is set up for two sparges, so you can take a look and see what the numbers give you. Good luck!

 

[Mike37]

Thanks for the link. I'll definitely be playing with that a lot before brew day.

It crossed my mind to sparge to boil volume on my stout first, then soak the grains in another pot for the baby beer.

I figure that since the baby batch is only 2 gallons, it won't need to be diluted to a large pre boil volume and therefore maybe it will be okay being third runnings instead of second.

Like I said, I'm not overly concerned with pulling fermentables into the baby batch.

 

[Mike37]

Okay, now that I'm starting to wrap my head around this whole thing, I say screw what my guests want. *I* now want to make a small batch of RIS and a regular stout from my same grain bill.

So my plan is to take my 8.5 pounds of grain and mash in about 4 gallons (I'll calculate that accurately later), producing about 3 gallons of wort which I'll boil down to 2 gallons for a small RIS batch. Then I'll sparge with about 7 gallons for a 5 gallon batch of 1.040 or so stout.

Make sense to anyone? Input?