Coolpooled DIPA

(5 gallons/19 L, all-grain)
OG = 1.081  FG = 1.018 
IBU = 58  SRM = 7  ABV = 8.3%

Ingredients

13 lbs. (5.9 kg) pale 2-row malt
3 lbs. (1.4 kg) white wheat malt
8 oz. (230 g) dextrin malt
13 AAU Centennial hops (15 min.) (1.25 oz./35 g at 10% alpha acids) 
20 AAU CTZ hops (15 min.) (1.25 oz./35 g at 16% alpha acids) 
0.75 oz. (21 g) Centennial hops (coolpool)
0.75 oz. (21 g) Chinook Cryo Hops® (coolpool)
2 oz. (56 g) Mosaic® hops (dry hop)
Yeast nutrient (15 min.)
Whirlfloc (15 min.)
Omega Yeast OYL-071 (Lutra Kveik) or your favorite neutral yeast such as Wyeast 1056 (American Ale) or SafAle US-05
3/4 cup corn sugar (if priming)

Step by step

This recipe uses a “Light Hoppy” water profile. Mash in all of the grains at 150 °F (66 °C) with 6 gallons (23 L) of water. After 45 minutes, batch sparge with 5.5 gallons (21 L) of water at 170 °F (77 °C). With my system I ended up with 7.5 gallons (28 L) in the boil. My evaporation rate is 10% per hour. You should adjust the sparge amount based on your evaporation rate — shoot for 7.5–8 gallons (28–30 L) in the boil for a 5-gallon (19-L) batch.

This is a 90-minute boil. Begin boil and after 75 minutes add the 15-minute hop additions. At the end of boil, rest for 15 minutes. Add 10% cold water (about 3 quarts/L), then cool to 180 °F (82 °C) with your chiller. I used the coolpool process described by Vinnie Cilurzo at Russian River Brewing. When the target coolpool temperature of 180 °F (82 °C) is reached, add the coolpool hop additions and hold this temperature for 20 minutes. 

After the coolpool, continue chilling the wort to yeast-pitching temperature (I fermented with kveik at 80 °F/27 °C, but other yeast will be cooler). When fermentation is complete, package as usual.

Extract version:
Substitute the pale and wheat malts with 7 lbs. (3.2 kg) light dried malt extract and 1.5 lbs. (0.7 kg) wheat dried malt extract. Bag the dextrin malt and add it to 6 gallons (23 L) of water as you slowly bring it up to 170 °F (77 °C) and rest there 10 minutes. Remove grains and bring to a boil. Turn off heat and stir in malt extracts, being careful not to scorch any on the bottom of the kettle. Once dissolved, return to heat and follow the remainder of the all-grain recipe.

Reflections:
The bittering notes were more subdued than I would like due to the low attenuation, but the flavors and aromatics were definitely enhanced from coolpooling. There is also a fruitier tone to the hop build, which I am pretty sure did not come from increased ester production of the yeast. (Lutra is very neutral at lower fermentation temperatures.) After having the beer in the keg for a month, I found that the aromatics maintained their punch and the increased hop expression held up. The only tools I have used in my brewing that offered a similar long-term benefit were thiol-enhancing yeasts and processes.

Since I can cool 5-7 gallons (19–26.5 L) of beer with a 50-foot (15-m) stainless immersion chiller rather quickly, I am not really sure this technique is as effective for my small system as it might be with a larger volume, but if it offers subtle flavors that would not normally be perceived it is a winning technique that is worth exploring.