Saturday, February 8, 2020

Passion Fruit Milkshake IPA 1.0

Long-time readers and friends will be familiar with the fact that I am not that fond of the IPA style in general.  I get far more enjoyment from the flavors inherent in specialty malts and yeast, as we find in Belgian style beers.  That said, I do occasionally drink one of the more flavorful IPAs like Rhinegeist Truth.  A number of friends and family members enjoy so-called Milkshake IPAs, and I've enjoyed some (and less, others) over the last few years.  Having spent a couple of years in Brazil and getting to experience the flavor of passion fruit first hand, I thought that might make a particularly interesting milkshake IPA.

I reviewed a few successful and popular Milkshake IPA recipes and settled on a grain bill that mixed barley, oats, and wheat to achieve the signature hazy thickness.  A high mash temperature should ensure some sweetness, with a bit of lactose to back that up.  Lots of passion fruit puree and the use of Southern Passion hops should bring the fruit flavors and aromas I'm looking for.

Ingredients

4 pounds Briess 2-row brewers malt
1 pound Whiteswaen Classic Wheat Malt
1 pound malted oats
1 pound Quaker flaked oats
a couple of handfuls of rice hulls
3 ml of 88% lactic acid
1 gram of Gypsum
3.6 gallons of mash water (Dublin Ohio tap water)
3 pounds of Vintner's Harvest passion fruit puree (fermenter addition)
2 ounces of Amoretti artisan natural passion fruit flavoring (fermenter)
1/2 tsp. yeast nutrient (15 min)
1.5 ounces Southern Passion hops pellets @ 12%AA (5 min)
8 ounces Lactose (during whirlpool)
4 ounces Lactose (at bottling)
1/2 tsp. Pure Vanilla Extract (late in primary fermentation
1/2 tsp. Pure Vanilla Extract (at bottling)
2 ounces Southern Passion hops pellets @ 12% AA (160F whirlpool 30 min.)
2 ounces Southern Passion hops pellets @ 12% AA (160F whirlpool 15 min.)
2.5 ounces Southern Passion hops pellets @ 12% AA (dry hop 7 days)
1 package LalBrew (Lallemand) American East Coast Ale yeast (dry)

Brewfather indicates the recipe has the following qualities:
  • Batch Size: 2.5 gallons
  • Original Gravity: 1.093 SG estimated, 1.094 SG actual before the addition of pain fruit puree, then 1.078 SG
  • Pre-boil Gravity: 1.064 SG estimated
  • Pre-boil Volume:  3.4 gallons estimated
  • Final Gravity: 1.031 SG estimated
  • IBUs: 51
  • SRM: 4.3
  • Brewing System:  Grainfather (modified)
  • Fermenter: n/a
  • Bottling Wand: Stainless 1
  • Carbonation method:  3 small tablets per 12-ounce bottle
Mash schedule:
  • Mash in and mash step 1:  155F for 60 minutes
  • Mash out 168F for 10 minutes
  • No-sparge method planned
Given the thin mash used, I decided I would not sparge this batch unless the pre-boil volume was below the intended amount.  I chose to go for a thin mash both to maximize mash efficiency and to reduce the chances of a stuck mash from all the wheat and oat in the recipe.

Boil schedule:
  • 60 minutes:  No additions
  • 15 minutes:  Yeast nutrient
  • 5 minutes:  1.5 ounces Southern Passion
  • 0 minutes:  Cool the wort to 160F and hold it there for whirlpool
Whirlpool schedule:
  • 30 minutes: Add 2 ounces Southern Passion
  • 15 minutes: Add 2 ounces Southern Passion
  • 0 minutes:  Chill to yeast pitching temperature while pumping into fermenter
Yeast properties:
  • This yeast is said to ferment in 7 days, and perhaps a bit slower than most ale strains.
  • The lag phase may be 24-36 hours
  • Medium to high attenuator
  • Medium flocculation
  • Neutral to slightly fruity and estery flavor and aroma
  • The optimal temperature range for fermentation is 59F to 72F
  • Lallemand rates it as having a moderate tropical fruit aroma/flavor, and lighter red apple, with possible hints of acid, alcoholic, and green apple to it.
Fermentation plan:
  • London Ale III likes to be between 59F and 72F.  Ambient basement temps at this time around around the lower end of that range, so I'm planning to keep the fermenter in the cooler part of the basement and let ambient air keep it cool.
  • Because I should be overpitching here, using a full package to 2.5 gallons, I'm not going to bother with rehydrating the yeast or creating a starter.  But I am adding a solid dose of yeast nutrient to help keep the yeast healthy, and I'll be splashing the wort well as it falls into the fermenter to ensure aeration.
  • Once the gravity is down near the last 10 points or so, I'll add the dry hops and then wait for the gravity to stabilize for at least 4 days (and up to 7) before bottling.
Post-Brew Notes and Observations

02/08/2020:  I crushed the barley, oat malt, and wheat.  I then added the flaked oats and rice hulls to the container and stirred everything well to get it all mixed together as evenly as I could.  I added a few scoops at a time and stirred after each addition, then gave it all a good stir at the end to break up any dough balls.   The 2.05 qt/lb mash thickness and rice hulls, I hoped, would prevent any stuck mash or (if I eventually do sparge) stuck sparge.

About 20 minutes in, mash pH read 4.95.  I added a quarter-teaspoon of calcium carbonate to bring it up a bit and waited 5 minutes to check the pH again.  Clearly I didn't need to add the Lactic Acid that Brewfather recommended. I should have at least waited to add it.  Lesson learned.  

Another 5 minutes after the calcium carbonate addition, the pH was still around 4.9.  I added another quarter teaspoon the try to bring it back up.  It continued to stay around 4.9.  After reviewing a Brulosophy experiment where a wort was intentionally mashed at a low pH and had no negative effect, I decided not to add any more calcium carbonate for fear of messing with the flavor.  Apparently there are some professional breweries that intentionally mash as low as 4.5 to get good results.

The Amoretti natural passion fruit flavoring recommends dosage of 7-14 ounces by weight per 10 gallons in drinks, which would work out to roughly 1.75 ounces for 2.5 gallons.  I decided to round that up to 2 ounces to ensure there's a clear passion fruit flavor in addition to that provided by the passion fruit puree.  

Gravity during the whirlpool hop stand registered 21.2 Brix, which for my refractometer is 1.094 SG.

When I pumped the chilled wort onto the passion fruit puree, then stirred it all in well, the gravity of the wort dropped to 1.078 SG.  That's lower than I wanted but acceptable.

02/09/2020:  There is clear activity from the airlock and the gravity has dropped down to 1.076 SG.  The temperature is reading 65F.

02/10/2020:  Gravity is down to 1.058 SG and temperature is up to 66F.

02/11/2020:  Gravity is down to 1.036 SG and temperature is up to 69F.

02/12/2020:  Gravity is 1.033 SG and temperature is down to 62F.  We're just two points from the expected final gravity.  At 9:30pm, the airlock was still bubbling nicely.  I opened the fermenter and dropped three tea strainers containing a total of 2.5 ounces of Southern Passion hops pellets.  I'm expecting this dry hop addition to kick off some hop creep, which will break down some of the residual sugars and cause additional fermentation, so I won't plan to bottle this until I've seen no gravity change for at least 3-4 days straight.  The last thing I want to see is this turning into a batch of bottle bombs and wasting the effort (and expense) that went into brewing it.  In fact, the gravity has already dropped from 1.033 SG when I wrote some of the earlier sentences to 1.032 SG.  The beer right now looks like a jug of passion fruit juice with about a half-inch head of yeast on top.  I'm hoping it turns out well.

02/13/2020:  Gravity has hit the original FG estimate of 1.031 SG today.  With the dry hops having only been added last night, I'm expecting the "hop creep" to drop it a little lower, but we'll see.  Regardless, I'll want to get the beer away from the dry hops no later than February 19 to avoid any grassy notes.

02/14/2020:  Gravity 1.030 SG and 62F.

02/16/2020:  Transferred the beer off the yeast cake and sediment, then tasted it.  The lactose was not detectable, as the beer primarily tasted dry and bitter with a distinct passion fruit note.  I ended up adding two ounces of lactose dissolved in distilled water and another half-teaspoon of vanilla.  This helped but wasn't enough, so I added another two ounces of lactose.  At this point, I debated what to do.  It was better now, but not as sweet as many milkshake IPAs I've had. I could add more lactose, but I thought that would risk another problem I've seen in these beers, which is that the over-use of lactose creates a weird, artificial flavor to the beer.  Since passion fruit is a tart fruit anyway, it seemed like a good idea to stop here and let the fruit's true nature come through.  I bottled it in 12-ounce bottles and loaded each with three small carbonation tablets each (low carbonation).  I'd have gone higher, but my concern was that the dry hops might cause some hop creep that would further increase carbonation.

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