Sunday, July 23, 2017

Belgian Trappist Single v2.2

Tonight I decided to run yet another test to dial in the gravity and volume calculations for my sous vide based brewing setup.  Since I had a Dubbel, Tripel, and Quad fermenting, doing a Trappist Single seemed like a good next step.

I have a Single recipe that I've been pretty happy with, but still wanted to tweak it a bit more.  This was a good chance to make those tweaks and see work on the calculations at the same time.

Ingredients

1 pound and 7 ounces 2-row Pilsner Malt
1 ounce Aromatic Malt
1 ounce Cara-Pils Malt
1 ounce Melanoidin Malt
0.15 oz. Styrian Goldings hops pellets @ 6.2% AA 60 min.
0.25 oz. Czech Saaz hops pellets @ 3.2% AA 15 min.
0.20 oz. Czech Saaz hops pellets @ 3.2% AA 5 min.
0.25 oz. Sweet Orange Peel
0.10 oz. Crushed Coriander
1/4 tsp. Irish Moss
Wyeast 3787 Trappist High Gravity yeast

According to my BeerSmith calculations, this brew should have the following characteristics:
  • Style:  Trappist Single
  • Original Gravity: 1.047 SG (11.7 Brix)
  • Pre-boil Gravity: 9.0 Brix
  • Final Gravity: 6.0 Brix
  • IBU: 25.5
  • SRM: 5.0
  • ABV: 4.9%
  • Volume: 1.0 gallons
  • BU:GU Ratio: 0.55
After brewing. the actual stats on this batch were:
  • Original Gravity:  12.0 Brix (vs. 11.7 expected) or 1.048 SG
  • Pre-boil Gravity: 7.0 Brix (vs. 9.0 expected) or 1.028 SG
  • Volume: 0.92 gallons (estimated)
  • Pre-boil volume: 1.56 gallons (measured)
Mash

The mash for this batch was done in a Ziploc bag, inside a stock pot full of water, to which the sous vide cooker was attached.  The sous vide cooker's temperature seems to be about 2 degrees below what it registers (i.e., if it says 156F the actual temp is 154F).  The contents of the Ziploc tend to be 3-4 degrees below the surrounding water (i.e., if the water is 156F, the bag's contents will be 152-153F).  Using this information, I adjusted the temperature settings so that I hit my intended mash and mash out temps.

Grain mashing in a Ziploc bag with the sous vide setup
The mash was conducted for 40 minutes at 156F, followed by a 10-minute mash out at 168F.

The grain was emptied from the bag into a strainer placed over the stock pot used for boiling.  As the grain drained and was sparged, the stock pot was heated to boiling.


Boil

Because I was trying to nail down calculations, I took a moment to measure the pre-boil volume.  It came out to 1.56 gallons versus the expected 1.64 gallons.  Pre-boil gravity was 7.0 Brix versus the 9.0 Brix calculated by BeerSmith.

The setup produces a good strong boil

The following boil schedule was followed:
  • 60 minutes:  Add Styrian Goldings bittering hops
  • 15 minutes:  Add Czech Saaz flavor hops
  • 10 minutes:  Add Irish Moss
  • 5 minutes:  Add orange peel, coriander, and Czech Saaz hops
  • 0 minutes: Turn off the heat, transfer the wort to a pitcher to measure post-boil volume
I achieved a post boil volume about 8-10 ounces short of the expected 1 gallon.  I'll use this info to tweak my calculations.


Fermentation

Trying to keep things simple, I transferred the wort into my plastic pitcher and placed it inside the mini-fridge to chill to yeast pitching temperature.  This will likely result in a cloudy brew, but my goal here was to check the flavor of the recipe and sort out calculations - not brew the clearest beer i could.

I had harvested a bunch of Wyeast 3787 from the BJ's Grand Cru clone I did last month, so I used some of that to ferment this beer.  If you've never used this yeast before, I strongly recommend a blow-off tube.  I've experienced some amount of blow-off with it regardless of the amount of head space, volume of wort, or gravity.  I set up a blow-off tube for this beer from the start.

The goal is to ferment the beer at ambient temperature with no temperature control for the first week, after which it will be moved to an insulated and heated chamber.  In there, it will be kept at 76F for another week or two until fermentation seems to have stopped.  After that, it will be bottled.

Post-Mortem and Other Notes

After my least batch in the sous vide setup, BeerSmith calculated my efficiency at 75% for the batch.  This time around, I used 75% as my estimated Brew House efficiency.  After completing the measurements, BeerSmith says I hit 71% efficiency for this batch.

I estimated boil-off for the setup at 0.64 gallons per hour. That's exactly what I achieved on this batch, going from 1.56 gallons to 0.92 gallons after a one-hour boil.

It looks like I probably needed about another 8-10 ounces of sparge water to hit the pre-boil volume on the nose.

Given that I used 2.5 quarts of water for mashing and 4.5 quarts for sparging, that's 7.0 quarts total.  My pre-boil volume measured as 1.56 gallons or 6.25 quarts.  This means the grain soaked up approximately 0.75 quarts.  That is 0.75 quarts for 1.69 pounds of grain or 0.44 quarts per pound.  I modified my spreadsheet to calculate future sparge volume based on 0.44 quarts being absorbed for each pound of grain.

One thing I have noticed about this setup in the last few batches is that it tends to not strain out all the bits of grain.  A certain amount ends up in the boil.  This is something to be addressed in a future run with the system.

Note all the grain particles in the pot at the boil
Update 07/25/2017:  The beer has a thin krausen on it now.  I'm not sure if it's hit the height of its fermentation or not yet, but there is very visible activity in the fermenter so I am not complaining.  It's beginning to lighten in color a bit, too, which is a sure sign that fermentation is underway.

Update 08/12/2017:  The beer has been bottled using Cooper's carbonation drops and has spent two weeks conditioning at 78F in the bottle to ensure carbonation.  It pours with a light level of carbonation, consistent with the carbonation drops but of course lower than a typical Belgian beer.  It pours an amber color, with a thin head that dissipates quickly.  The aroma is mild, with hints of fruit and spice.  The hops come through pretty clearly in the flavor, which is expected for this style.  I'll need to scale the recipe up to see if I am convinced it's better than previous attempts at a Single, but so far I'm hopeful.

Update 01/01/2018:  The beer has now been in the bottle for over four months. I poured the glass pictured at the start of the article today.  It pours a nice gold color with a thick white head that lasts for about 30 seconds before reincorporating into the glass.  The aroma is fruity, herbal, and sweet.  The flavor is dry and balanced, compared to the aroma.  Hops definitely balances the malt in this one, and takes the foreground after the initial sip and into the finish.  The finish is clean but with a lingering bitterness.  Let's compare this with the BJCP style guidelines:

  • Aroma (12 points max):
    • Style Definition:  Medium Trappist yeast character showing fruity/spicy/floral notes. Low grainy-sweet malt backdrop, possibly with light honey or sugar quality. 
    • My Version: Yeast character comes through clear, definite fruity notes, with malt there if you look for it. I'd score it an 9 here.
  • Appearance (3 points max):
    • Style Definition:  Pale yellow to medium gold color. Generally good clarity, with a moderate-sized, persistent, billowy-white head with characteristic lacing.
    • My Version: Definitely on the medium gold side, maybe a touch too dark. Clarity is decent but there is a slight haze. The large white head lasted a while but is not leaving behind lacing and wasn't what I'd call "billowy". I'd score it a 2 here.
  • Flavor (20 points max): 
    • Style Definition: Fruity, hoppy, bitter, and dry. Initial malty-sweet impression with a grainy-sweet soft palate and a dry, hoppy finish. The malt may have a honeyed biscuit or cracker impression. Moderate spicy or floral hop flavor. Esters can be citrus (orange, lemon, grapefruit), pome fruit (apple, pear), or stone fruit (apricot, peach). Light to moderate spicy, peppery, or clove phenolics. Bitterness rises towards the crisp, dry finish, with an aftertaste of light malt, moderate hops, and yeast character.
    • My Version: Starts mildly sweet and citrus, then dries out and becomes bitter and clean at the finish. The aftertaste is mostly hops and a hint of yeast.  A hint of biscuit malt. Floral hops come through. I'd score this a 16.
  • Mouthfeel (5 points max):
    • Style Definition: Medium-light to medium body. Smooth. Medium-high to high carbonation, can be somewhat prickly. Should not have noticeable alcohol warmth.
    • My Version: Definitely medium-bodied.  Not heavy or thick, but not watery.  High carbonation, on the effervescent side but not what I'd call prickly. No alcohol warmth. I'd score it a 4.
  • Overall Impression (10 points max):  
    • Style Definition:  It should be a pale, bitter, dry, and well-carbonated beer with a fruity yeast character, spicy-floral hop profile and soft, supportive malt palate.
    • My Version:  It's more gold than pale, coming in around SRM 6 by my best guess, so it's a little darker than the style wants it to be.  It's mildly bitter and well-carbonated, and the fruity herbal/floral hop profile is definitely here. If I was a judge rating this for another brewer, I might score it a 7/10.
  • TOTAL SCORE: 38/50

How would I improve the score?

  • On the aroma side, maybe increase the last Saaz addition by 25% or so, or add one closer to the end of the boil so that the aroma is enhanced a little.  This would also bump the bitterness up a tiny bit, which wouldn't hurt against the style definition. 
  • On the appearance end, I'd make sure it received gelatin finings before bottling to clear it up a bit more. I'd also swap some of the Pilsner malt for some Cara-Pils to try to improve the lacing. I'd like to add more Melanoidin, but that might bump the color up too much. 
  • For mouthfeel, maybe a touch more carbonation.
  • On the flavor side, increase the hops addition a little, but not much. It definitely tends toward hops right now, but could maybe use a slight nudge to get closer to the guidelines.

Other than the above, I think I've done as well as I can with this one.

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