5-1/2 hours, 1 Keggle, 5 gallons of Imperial stout, 10 gallons of Irish stout

[Hazarmaveth]

I've been wanting to brew an imperial stout for a while, and I also really wanted to make some session stout, so I decided to do a partigyle and get both in one brew day. I then had the crazy idea to try to do this as quickly as possible, using shortened mash and boil times. The plan was to make 5 gallons of a not-too-excessive imperial stout, and 10 gallons of dry Irish stout.

Grains:
20lb Maris Otter
4lb White Wheat
3lb Roasted Barley
2lb Chocolate Malt

6oz Roasted Barley added to second gyle
4oz Pale Chocolate Malt added to second gyle

Hops for Imperial stout:
2oz Magnum 30min
1oz Huell Melon 5min

Hops for Irish stout:
1oz Magnum 30min

Yeast: Wyeast 1318, big starter


I filled my keggle with a little over 9 gallons of water and turned on the heating element at 2:47.

Here you can see the shoddy gallows I constructed for hanging BIAB bags.

The water reached strike temp and I turned the heat off and mashed in at 3:28. My mash temp ended up at 158.5, slightly higher than my 157 target, no big deal. I stirred the mash vigorously with my comically large whisk.

I continued stirring and manually recirculating the mash for a short 25 minutes, then hoisted the bag, squeezed it a little and started draining the pitch-black wort into a bucket at 3:53. I measured the sg at 1.083.

29lbs of grain is a lot of grain.

I then filled the keggle with 9 more gallons of water and turned the heat back on. At 4:21, once the temperature had gotten into the 150's, I lowered the bag back in, added the additional 10oz of roasted grains and stirred again.

I lifted the bag a second time 16 minutes later at 4:37. The sg of the second gyle measured at 1.031. So now I had about six gallons of 1.083 wort and 10+ gallons of 1.031 wort, and my pre-boil targets were 6 gallons at 1.074 and 11 gallons at 1.038. I did a little math and proceeded to swap a gallon of each wort into the other wort. The result was 6 gallons at 1.074 and 10+ gallons at 1.036. Close enough. At this point I added the bittering hops to their respective worts.

Here's a picture of samples of the two gyles before mixing. First gyle on the left, second gyle on the right.

At 5:00 I turned on the heating element to bring the Irish stout wort to a boil and drank a bottle of Founders Double Trouble. I saw it start to boil at 5:35, turned the heat off 31 minutes later at 6:06, and began cooling the wort with my homemade 50ft 1/2" copper chiller. Once it got under a hundred degrees I switched from hose water to recirculated ice water, allowing me to pitch the yeast at 6:45 into 67-degree wort.

I put the Imperial stout's wort back into the kettle and heated it to a boil which started at 7:24. The Huell Melon hops were added at 7:49, and heat was turned off at 7:54, a 30-minute boil. I cooled it down the same way as the first boil, pitched the yeast at 8:12, drained it into my new Fastferment plastic conical, and closed the lid at 8:18, five hours and 31 minutes after turning on the heat for the first mash. That's really not much longer than it generally takes me to make a single 5-gallon batch, so I'm pretty happy with how the brew day went.

I ended up with about 5.25 gallons of the Imperial stout with an OG of 1.087 (1.089 was the target), and about 9.25 gallons of the Irish stout with an OG of 1.047 (1.045 was the target). My math says that's right around 83% efficiency, not bad at all. Signs of happy fermentation began in less than twelve hours.

This has been a fun little experiment. I'll post an update with tasting notes once the beer is in kegs.

 

[JohnSand]

Well done. I've brewed two successive batches by using one kettle of strike water, a cooler mash tun and an old kettle. Two mashes, one short one long, followed by two short boils.

 

[Hazarmaveth]

Yeah, that'll certainly do it. Did you run the two boils simultaneously? That could knock another whole hour off the brew day. Preheating the sparge water would be worth another 20 minutes or so. I need another kettle.

I'm not sure why two of those pictures are upside-down, lol. They're the right way around on my phone.

 

[JohnSand]

I only have one burner, so the boils were in succession. But most of my boils are only 30-40 minutes long (post hot break).

 

[wilserbrewer]

Any trouble removing that large a grain bill from the narrow keggle opening?

The bag shape w sharp taper is designed to help, curious if you had any issues.

 

[Hazarmaveth]

Yes, a little bit. The bag wanted to be about 1/2" larger than the opening. Fortunately I have that cut edge rounded over and polished, so I was able to yank it through without any serious issues. I had the bag filled with grain just beyond the end of the sharp taper. A few pounds less grain likely would have been no trouble at all.

 

[Hazarmaveth]

I have some of the Irish stout on tap now. It's pretty good. I've certainly had better, but it's quite drinkable and certainly recognizable as an Irish stout. It could use a few more IBU's, and the flavor from the roasted grains is missing... something. Mouthfeel is great, probably due to the 2lbs of maltodextrin that I added. The high mash temp can't have hurt either, although it did lead to a high FG of 1.020, meaning this beer ended up at about 3.5% ABV. That works for a session beer. There is virtually no perceptible residual sweetness.

 

[JohnSand]

Thanks for the update.

 

[Hazarmaveth]

Now that the Irish stout has spent a couple of weeks in the keg, it's actually become a pretty darn good beer. The roasted grain flavor has sort of morphed into a nice mix of bittersweet chocolate and black coffee, a touch of malty sweetness has started to come through just enough to make the thick mouthfeel seem more appropriate, and I don't feel like it's missing bitterness as much.

I still haven't so much as taken a gravity reading on the Imperial stout. The yeast seams to have done what it needed to do. I'll probably keg it in a few weeks.

 

[JohnSand]

Good news. I haven't done a stout, but I'm planning one in time for St. Patrick's Day.

 

[boxboybrewing]

Sir, that is not a comically large whisk. I have one aptly named "The Whisk of Destiny!" Cue the dramatic music...