Butternut Squash Spice Ale version 1.0

My wife is a big fan of pumpkin ales. Some time ago, I purchased the ingredients for one that I never got around to making until today.

If you look at the Northern Brewer web site, you may recognize this as being similar to their Smashing Pumpkin Ale recipe. That was my starting point. I added Butternut Squash to it because we had one in the kitchen that we had no plans for. I also added Melanoidin Malt to give it a little bit of the crust/biscuit flavor that you find in Southern Tier's Pumking. I could have added Victory Malt like they do, but I am hoping the Melanoidin will give a more subtle crust-like flavor and some added sweetness to accentuate the pumpkin pie flavor profile.

I bought the grain for this recipe over a year ago and hadn't used it. I decided to get it out and make it, not knowing if the age of the grain would ruin the result or not. Even if it did, I figured it would be good practice to make it.

The Recipe

7.5 pounds 2-Row Pale Malt
2.5 pounds Munich Malt
8 ounces Caramel 80 Malt
8 ounces Melanoidin Malt
4 ounces Caramel 60 Malt
1 pound Roasted Butternut Squash
0.85 ounces Cluster hops @ 7.2% AA
1 teaspoon Pumpkin Pie Spice
1 packet Safale US-05 American Ale Yeast
0.5 tsp. Yeast Nutrient
1 tube White Labs Clarity Ferm
Super Irish Moss
1 Tbsp. pH 5.2 Stabilizer

Per BeerSmith and my equipment profile, the beer should have the following characteristics:

• Original Gravity: 1.057 SG (14.0 Brix)
• Bitterness (IBUs): 17.4
• Color (SRM): 10.1
• ABV: 6.0%
• Pre-boil Gravity: 1.056 SG (13.8 Brix)
• Final Gravity: 1.011 SG (estimated at 7.3 Brix on a refractometer, accounting for alcohol)
• Bitterness Ratio: 0.308 IBU/SG
• Batch Size: 5.78 gallons
• BH Efficiency: 80%
• Estimated Pre-boil Volume: 6.4 gallons

When the brewing was over, my actual results were:

• Original Gravity: 14.1 Brix or 1.0573 SG (slightly higher than expected)
• Pre-boil Gravity: 13.9 Brix or 1.0564 (slightly higher than expected)
• Pre-boil Volume: 6.4 gallons (exactly as estimated)
• Post-boil Volume; 6 gallons
• Fermenter Volume: 4.9 gallons (below the 5.1 gallons estimated)

After the beer is finished brewing, I'll update with the ABV and other info.

Mash Schedule

The beer will be brewed in iMake's The Grainfather RIMS system, with the following mash schedule:

• 4.75 gallons tap water place in the kettle with a Campden Tablet to remove chlorine and chloramine from the water. 2.5 gallons place in the sparge water kettle and treated with part of a Campden tablet to remove chlorine and chloramine.
• Mash water heated to 152F
• Grains and squash added, plus pH 5.2 Stabilizer added. Recirculation pump turned on.
• 30 minutes mash time at 152F
• 60 minutes mash time at 158F
• 10 minutes mash-out at 168F
• Sparge with 2.5 gallons at 168F

Grain basket is removed, grains removed from it, and the basket cleaned while wort reaches a boil.

Grain and squash, post-sparge

Boil Schedule

A 60-minute boil will be performed, with the following schedule:

• 60 minutes: Add Cluster hops
• 30 minutes: Sample of wort removed and allowed to cool
• 20 minutes: Add Super Irish moss to cooled wort sample
• 15 minutes: Add yeast nutrient
• 10 minutes: Add rehydrated Super Irish Moss and whirlpool a bit
• 7 minutes: Recirculate boiling wort through chiller to sterilize it
• 0 minutes: Add pumpkin pie spice, remove hop spider and hops, whirlpool while running cold water through wort chiller to cool it down. Pump wort into fermenter.

The boil getting started, before hops addition

Fermentation Schedule

With the wort temperature in the 59-75F range, I pitched the US-05 dry yeast directly into the wort. 

Owing to unusually cool tap water, wort entered the fermenter at approximately 64.6F. I calibrated the temperature on the InkBird controller and attached a fermwrap heater to get the wort into the recommended 59-75F range for the yeast.

My goal is a 1-2 week fermentation, followed by cold-crashing and then bottling.

Bottling

On February 25, 2017, I decided it was time to bottle the brew. A refractometer reading of 7.9 Brix, adjusting for original gravity and the presence of alcohol, gave me a final gravity (according to BeerSmith) of 1.015 SG and an alcohol content of 5.48% ABV. This is in the ballpark of what I was expecting.

I calculated that adding 5.35 ounces of corn sugar to the bottling bucket should bring the beer to a finished carbonation level of 2.8 volumes of CO2. That should allow the aromatics of the squash and spices to be detectable, and combined with the Melanoidin malt give a nice head, too. 

My final yield was approximately 16 bottles of the 12 to 16 ounce size and at least 18 of the 22 ounce variety. The beer is cloudy at this point, with a nice orange color to it, a hint of pumpkin spice to the aroma, and a mild flavor. The flavor hints at the squash and spices, and is neither too bitter or too sweet. I'm happy with it at this point, though the real test comes when it's conditioned and chilled.

The bottles were placed in my marine cooler with a heating element and temperature controller set to keep the "hot box" at 76F inside. My plan is to leave the bottles here until March 11, 2017, when I'll chill one and see how the carbonation is. If the beer is properly carbonated, I'll chill it for a few weeks in the fridge to clarify it a bit.

Post-Mortem and Other Notes

The only issue I had during this one was the sparge. My sparge water got too hot before I had removed the grain basket from The Grainfather. It had reached over 200F. I turned off the heat and allowed it to cool, but it cooled a little too much and ended up around 150-160F when I started the sparge. Sparging took quite a bit longer than usual, probably because of the cooler water. (By the end of the sparge it had gotten down below 150F.) That's a mistake I don't want to make again. It didn't seem to hurt the gravity or volume, just took a lot longer to complete the sparge.

Owing primarily to a lot of sediment in the kettle, I didn't achieve the 5.1 gallon volume I expected in the fermenter. I decided to turn the pump off before it sucked up too much of the sediment, which resulted in reaching just under 5 gallons in the fermenter.

Update 3/5/2017: The beer has been conditioning in the bottles for about a week now. I popped one in the fridge yesterday and opened it last night. At this point, it's a cloudy orange-brown color with a very thick long-lasting head (thanks to the Melanoidin malt I expect). The first thing I noticed was a diacetyl aroma and flavor, which took some work to get past. Having opened a bottle too early in the past, my expectation is that this diacetyl issue will clear itself over the next week or so as the yeast finishes cleaning up the beer. I'm happy that there was no carbonation issue with this batch, as there have been with some other recent batches - so taking the additional time to calculate the proper priming sugar dose based on volume and temperature seems to have helped.