Imperial Stout / Dark Mildish Porter Parti Gyle

[Brewsmith]

I’m planning my next couple brews right now. I’ve put together an Imperial Stout recipe with a repitch of some WLP-001 that I have in a fermenter. With winter break coming and having days off from teaching, as well as needing to get my homebrew supply back up, instead of just doing an imperial stout, why not do a parti gyle and get two beers out of it? It’s been years since I’ve done one, so I figured I’d bounce this off you guys.

Here’s the original imperial stout recipe. My batch size is 5.5 gallons. For normal beers I collect 7 gallons of wort after fly sparging and end up with 5.5 gallons in the fermenter after an hour boil. Originally, I was going to collect much more than the 7 gallons and just boil longer, but now I’m throwing that all out. Here’s the original grain bill:

5.5 US Gallons
80% efficiency 1.102 OG

15 lbs pale malt (75%)
1.5 lbs flaked barley (7.5%)
12 oz roasted barley (3.8%)
12 oz chocolate malt (3.8%)
8 oz black patent malt (2.5%)
4 oz pale chocolate malt (1.3%)
12 oz crystal 80 (3.8%)
8 oz crystal 120 (2.5%)

Now to make this a parti gyle, I’m considering scaling this up by 50%, and then collecting the first 7 gallons of runoff for the imperial stout and then the next 7 gallons for the other beer. Style-wise it’s going to be somewhere between a dark mild and an English porter. I’m going to use WLP-002 on the second runnings.

The entire grain bill for the total of an 11 gallon batch would be:

21.5 lbs pale malt
2.25 lbs flaked barley
1.125 lbs roasted barley
1.125 lbs chocolate malt
0.75 lb black patent
6 oz pale chocolate
1.125 lbs crystal 80
0.75 lb crystal 120

My question is this: does this seem reasonable? My mash tun is a 10 gallon cooler and this is going to max it out. I already fly sparge, and if I batch sparged, I would need to do several batches to make this work. I’d rather just collect the wort like I normally would, just more of it.

To answer a few possible questions already, I plan on taking gravity readings pre-boil for both to adjust the hop schedule. I didn’t post the hops because it could be a little variable, and I can make those adjustments the day of.

I’m not trying to get completely hung up on numbers. I know there’s a way calculate first runnings gravity based on mash water and grain bill. I’m mostly looking for some parti gyle experts to say I’m at least pointed in the right direction, or steer me away from something I’m overlooking.

Cheers everyone. It’s been good to be more of a regular around here again.

 

[Northern_Brewer]

Some random thoughts having finally done my first partigyle (BIAB) just this week :

You know your system, but don't assume you'll get your normal efficiency - partly because efficiency always goes down with higher OGs, but also when you're absolutely brim-full it just gets harder to mix things, eliminate doughballs etc.

Especially if it's your first time, it's probably worth just dialling back the target volumes by 10% or so, just to give yourself a bit of room to manoeuvre. Effectively you have the grist for two beers in one mash and...it's a lot.

Consensus seems to be that you should expect second runnings somewhere in the region of 30% of the gravity of the first, but I was more like 50% -I was aware of not being terribly efficient in extracting the first runnings and that's OK, I was just trying to get a feel for the process and not spill the grist from my bag...

All the credible sources on partigyling (ie not the US ones) are insistent that you should always blend the two gyles and not simply make beer from 100% first runnings and 100% second runnings - too much of the good flavour comes in the first runnings so you should always blend even if it is just 10%. I did 3:1 and 1:3.

Arguably roast barley is taking the small beer away from mild or porter and more into simple "stout" in the modern sense. Mine was a more Belgian-inspired grist, going heavy on Simpsons DRC.

Personally I find WLP002 possibly the least interesting of all the British homebrew yeasts. Having enjoyed WLP540 and harvested Rochefort yeast (similar, but quite a lot more complex than 540) in a pale beer, I'm looking forward to what they can do in something that should be more of a natural home for them, despite the name they're more British than Belgian in style.

 

[Jack Arandir]

I tried several partigyle beers and decided the best way to handle it is to focus on the first (bigger) beer and treat the second (small) beer as a side project. Trying to hit numbers on two independent variables is more work than just making two beers. Gravity, mash pH, flavors just get wonky with that much sparging.

Last partigyle, I focused on the first beer and brewed it normally. Then my buddy took the spent grains and made a second beer off it, tossing in some extra base malt to bulk up the mash. The first beer was great, the second beer okay (but effectively free). The best way to describe the flavors was "muddy". The grains give up their best flavors on the first runnings, then things get progressively worse.

One thing to note: You're pushing 30 lbs of grain with that recipe. I have a 12 gal mash tun and 30 lbs is my absolute max. My friend uses a 10 gal mash tun and his max is 25 lbs. Also, your calculations may be based on 80% efficiency, which you won't get with a 1.102 beer. But I think you took that into account.

Your recipe looks good. When you say pale malt do you mean 2-row (i.e. Briess) or a mild or Maris Otter malt? I personally don't like 2-row and have moved away from it in everything but IPAs. It's the vast majority of your grain bill, so use a base malt with great flavor.

Also, use caution with crystal malts in the 80-150 range. They are what's called the "harsh zone" where flavors can be bitter and unpleasant. I've used crystal 80 and 120 in beers and was unhappy with it; I've moved to Munich, Melanoidin, and Pale Chocolate to approximate those flavors instead.

Good luck!

 

[DBhomebrew]

https://barclayperkins.blogspot.com/2010/04/party-gyles.html?m=1

 

[Brewsmith]

One thing to note: You're pushing 30 lbs of grain with that recipe. I have a 12 gal mash tun and 30 lbs is my absolute max. My friend uses a 10 gal mash tun and his max is 25 lbs. Also, your calculations may be based on 80% efficiency, which you won't get with a 1.102 beer. But I think you took that into account.

Your recipe looks good. When you say pale malt do you mean 2-row (i.e. Briess) or a mild or Maris Otter malt? I personally don't like 2-row and have moved away from it in everything but IPAs. It's the vast majority of your grain bill, so use a base malt with great flavor.

Also, use caution with crystal malts in the 80-150 range. They are what's called the "harsh zone" where flavors can be bitter and unpleasant. I've used crystal 80 and 120 in beers and was unhappy with it; I've moved to Munich, Melanoidin, and Pale Chocolate to approximate those flavors instead.

Good luck!

I’m going to mash thick to save space. I’m aware I’m pushing the limitations, and I’m prepared to make the mash water adjustments.

On the efficiency, that was mostly a default from how I design my standard recipes and my system. I’m not so worried at exactly what the actual gravity is, but I will measure it before the boil.

I’m using US 2 row malt.

I’ve used the darker crystals in my recipes, including stouts, before and have not had a problem with harsh flavors. Here I definitely want some of the deep caramel, to plummy flavors they bring. I’m a big fan of crystal 120 and 150, but you do need to know how to use them.

 

[kevin58]

If you can find it there is a great book called Guile Brews by Peter Symon which goes into great detail on the partigyle method and includes some formulas for figuring things out... as well as some recipes to try.

 

[DuncB]

Try here

https://www.lulu.com/shop/peter-symons/guile-brews/paperback/product-24393105.html?page=1&pageSize=4

 

[Brewsmith]

I’m brewing this right now. I’m going ahead with my original plan. The first runnings are going to be an Imperial Stout using re-pitch Cal Ale WLP-001. I’ll measure the gravity pre boil to dial in the bittering hops. I have a bunch of Apollo and Bravo that need to get used up plus a few other things that I’m still deciding what combination to put in, but it doesn’t need a ton of late hop character.

The second runnings are going to be an English porter with English Ale WLP-002. Again I will measure gravity pre boil for bittering hop, which will be UK Phoenix since that’s the only English hop currently in my freezer.

I’m mashing thick at just under a quart per pound to make sure it all fits in the 10 gallon mash tun. I’ll post updates as it goes. The photo is the grain bill.

 

[Brewsmith]

First snag of the brew, the grain all fits but my water estimation was about a half gallon too much for the mash tun. It looks like I’ll be doing a manual mash recirculation.

 

[Brewsmith]

The good news is that the mash temperature is good. I think about every 15 minutes I’ll pull a gallon and add the other liquid back.

 

[InspectorJon]

I'll leave this here in case someone reads this for reference later. I am also interested in @Brewsmith 's experience. I researched this a lot last winter before making a BIAB imperial stout in my 7 gallon pot. There seems to be a consensus that one quart per pound is as thick as one should go for a successful mash. That worked out OK for me with a good size batch sparge to fill my kettle. one needs a second large pot/kettle for the batch sparge. This seems similar to what Brewsmith is attempting.

 

[Brewsmith]

I was 28 quarts for 29 lbs. But 2 quarts wouldn’t fit. If I had known, 26 quarts for the grain bill would have just fit and still barely coverd the grain bed

 

[Brewsmith]

Now that we are getting near the end of the mash, with all of the absorption and air out of the grain, it’s looking like I might be able to barely fit the entire liquid volume. Let’s see how close it gets!

 

[Brewsmith]

It fits! We’re at the 60 minute mark right now and it’s been right at 150 the whole time. I’m going to let it go a little longer and then start running off.

 

[DuncB]

Reiterated mash is another option for big beers and mash tun capacity issues.
Both methods make for a long stressful brewday.

 

[Brewsmith]

First 7 gallons for the imperial stout is done. Runoff for the porter is going. Trying to keep up with the sparge water. I should make it.

 

[Jack Arandir]

Good luck! That's one heck of a mash there!

 

[Brewsmith]

Runoff is finished. 14 gallons of wort. Sample for pre-boil gravity on the imperial stout is cooling. Now it’s just two regular boils, and a longer brew day. The imperial stout wort smells of grainy molasses.

 

[Brewsmith]

Accounting for temperature, pre-boil gravity is at 1.082, which should give me a OG of around 1.104, which is not far off from my estimation.

For hops I’m going with Apollo at 60, Apollo and Bravo at 30, and Cascade at 15. The Apollo and Bravo both remind me of the fruits in fruitcake and cascade will add the orange/grapefruit peel note. Between the molasses and fruit, we’re shooting for roasty fruitcake which I think should compliment well. Let’s see how the rest goes.

 

[Brewsmith]

I saved some of the final runnings just to check. Gravity was at about 1.022. It was mildly sweet with a note of molasses and some bitter cocoa. I think things are pretty much on track. The boil is done, just waiting to chill down and get it into the fermenter, then it’s go time on brew number two.

 

[Brewsmith]

Imperial Stout is in the fermenter. OG came in just a couple points lower at 1.098, which is about where I wanted to end up anyways. Wort tastes of plummy molasses and dark chocolate. I think this is going to be good when it ferments out.

The porter is getting up to a boil now. About to get the pre-boil gravity

 

[Brewsmith]

Second runnings are at 1.031 pre-boil, so we are looking at around 1.039 OG. I’m going to shoot for about 20 IBUs of bittering hops and that’s it. Whether it’s a porter or dark mild, I don’t really care. It’s going to be an easy drinker.

 

[Brewsmith]

Second beer came out with an OG of 1.038. After a 10 hour brew day I’m done. Aside from the difficulty of getting everything in the mash tun at the beginning, everything else went pretty smooth. I definitely maxed out my system, but it’s good to know exactly how much I can fit in there. I definitely want to do some more parti gyle beers, but I will need to schedule them for when I have a full day to set aside.

 

[DuncB]

@Brewsmith

Well done. My partigyle came out with 25 litres at 1.107 and 25l at 1.037.

Next time I think my mash efficiency will be better with some adjustments and technique improvements and I'll monitor 2nd runoff and sparge with less in batch 2.

I'm looking forward to it with trepidation. But will try it on a belgian tripel and perhaps a saison from the runoff which would suit an addition of dextrose if the numbers aren't quite right. Which is highly likely!

I might try super thick mash, drain and squeeze into another vessel then add more water for total mash volume repeat drain and squeeze and then a fly sparge to get the final volume in batch one.
This might improve my extraction over my first more classic attempt of thick mash drain, sparge. Then resparge for batch 2.

luckily a few months away so time to get my strength up.