[klickitat jim]

I listened to February Brewing With Style - Big Beers. He describes an interesting procedure he calls "poly-gyle". No, not party gyle. I was intrigued but had unanswered questions, primarily what happens to mash pH. Google found me a discussion where it seems not much happens to pH.

Example: I'm considering a Imperial Stout. Target volume in the fermentor 6 gallons of 1.100. Using poly-gyle, no sparge, I would mash in 14lbs (half of the grain bill) including all of my specialty grains to the full volume. That gets ran off to the BK. Dump spent grain, add remaining 14lbs, all of which is base malt. Heat the wort to strike temp and sublet it back into the MT to mash a second time. Run off to BK and continue as a normal brew.

Evidence shows the mash pH will only drop about .1 at most in the second mashing. With my recipe and DI water my initial mash pH would be 5.4 making the second mash about 5.3 lowest. Doable.

Benefits I see are
1. Mash tun won't hold 12 gallons and 28lbs.
2. No sugar
3. No DME
4. Something fun and new to try

Whatcha think? Anyone try this?

[brewinhard]

All I can think of is that I would be majorly oxidizing my wort with all that movement. But then again, I don't have any pumps to work with, so there's that...

[klickitat jim]

Ya I only move by pump.

BTW, before some one freaks. We don't have RO near me, so when I need you use DI. And it's not just plain... I build it.

[hopfenundmalz]

I think that is also termed double mashing by some, it is one way to get much higher gravity in the kettle, at the expense of some efficiency. I have thought about giving that a try.

[Stevie]

This is only really useful when there is limited capacity. I’d be down to try it out just to see what I think.

[Robert]

I think that is also termed double mashing by some, it is one way to get much higher gravity in the kettle, at the expense of some efficiency. I have thought about giving that a try.

Think some old English sources called it "doble-doble" and they used it to brew very strong ales for special occasions, e.g. brew it when your son is born, keep it till he's 21. (Guess oxidation REALLY doesn't matter there.)

[Robert]

Ya I only move by pump.

BTW, before some one freaks. We don't have RO near me, so when I need you use DI. And it's not just plain... I build it.

Jim, got this recently and love it.  Just use it for brewing water, runs 10 gal in ~3 hours.
APEC Portable Countertop Reverse Osmosis Water Filter System, Installation-Free, fits most STANDARD FAUCET (RO-CTOP) https://www.amazon.com/dp/B00IB14XDU?ref=yo_pop_ma_swf

Won't buy DI or RO anymore!

[klickitat jim]

It's need to me. I'm sure it's not new though. How it works is confusing but my understanding is that when you mash in the second round, only the water from the wort enters the new grain. Then new sugars are extracted. Interesting stuff. I'm going to give it a go next brew day.

[klickitat jim]

Ya I only move by pump.

BTW, before some one freaks. We don't have RO near me, so when I need you use DI. And it's not just plain... I build it.

Jim, got this recently and love it.  Just use it for brewing water, runs 10 gal in ~3 hours.
APEC Portable Countertop Reverse Osmosis Water Filter System, Installation-Free, fits most STANDARD FAUCET (RO-CTOP) https://www.amazon.com/dp/B00IB14XDU?ref=yo_pop_ma_swf

Won't buy DI or RO anymore!

I usually brew with my we'll water. Except on rare occasions when we get a warm stretch and huge runoff, and my we'll goes hazy,  like right now. But if it clears I'll use we'll water.

[Robert]

Ya I only move by pump.

BTW, before some one freaks. We don't have RO near me, so when I need you use DI. And it's not just plain... I build it.

Jim, got this recently and love it.  Just use it for brewing water, runs 10 gal in ~3 hours.
APEC Portable Countertop Reverse Osmosis Water Filter System, Installation-Free, fits most STANDARD FAUCET (RO-CTOP) https://www.amazon.com/dp/B00IB14XDU?ref=yo_pop_ma_swf

Won't buy DI or RO anymore!

I usually brew with my we'll water. Except on rare occasions when we get a warm stretch and huge runoff, and my we'll goes hazy,  like right now. But if it clears I'll use we'll water.

Well, you can't beat a good well.  For advertising purposes call it "natural artesian spring water." Yours is good?

[klickitat jim]

As good as it gets in my opinion. Except when it blows.

[Robert]

As good as it gets in my opinion. Except when it blows.

That is one sweet looking water report!

[klickitat jim]

It usually blows in January. That's when I brew German ish lagers using DI so I can get away with minimal acid. Plus it's cold and my we'll water is about 40f for chilling

[Robert]

It usually blows in January. That's when I brew German ish lagers using DI so I can get away with minimal acid. Plus it's cold and my we'll water is about 40f for chilling

Hear ya.  My city water is doable on HCO but calcium is a little low (~25) and everything else is so borderline no room for more Na, SO4 Cl etc) it was hard to just go seasonal (it does vary seasonally.) You're lucky indeed.  But building every batch, I realize I'm free to brew anything anytime!

[klickitat jim]

I think I figured out how to correct for the drop in pH in the second mashing. In theory...

I plan to split my grain bill in half, mashing with the full amount of water. All of the specialty goes in the first mash along with enough of the base malt to make it two equal portions. I calculated what my acid needs are for that. Then I added the second mash grains to the calculation and recompute for total acid needed. Deduct the acid I will put in the 1st Mash and the remainder "should" be the acid I need to add to the 2nd mash.

I need 4ml Lactic 88% in the first half, 7ml for the full grain bill, so 4ml 1st Mash and 3ml added to the 2nd.

Seems like a better method than using too much acid in the 1st Mash, or just hoping the 2nd mash doesn't drop too far.