Saturday, November 24, 2018

Big and Mead-y Ale 1.0

While enjoying one of Avery Brewing's high-gravity beers recently, I began to wonder just how hard it would be to brew a beer in excess of 16% alcohol by volume. The best I've managed to date has been a Belgian-style dark strong ale that came in at 12.8% ABV. Could I really push yeast to deliver a beer (in this case a hybrid of mead and beer) at 16% or higher ABV? I wanted to find out.

I began by researching what's known and published online about "really high gravity" brewing like this. Below is what I learned:
  • Some sources suggest aiming for an OG of 1.106 initially. Others suggest keeping it to 1.120. White Labs, in its notes for WLP099 Super High Gravity Yeast, suggests a lower gravity - something that would produce a 6-8% beer, and adding fermentables later.
  • Wort pH during the mash should stay between 5.0 and 5.3.
  • Be sure to increase the amount of hops used to offset the higher gravity and sweetness of the alcohol you'll be generating.
  • Add nutrients, adjuncts, and fermentables as the yeast chews through them.
  • Keeping the wort well-aerated during the first 24-48 hours is critical.
  • Pump or agitate the wort during fermentation to keep yeast in suspension, increase oxygen in the wort, and allow CO2 to be released.
  • Adding glucoamylase and/or papain during fermentation can help keep the yeast going and provide additional fermentable sugars.
  • Keep pH between 4.5 and 5.0 during fermentation.
  • When the yeast has attenuated two-thirds of the sugars, stop adding nutrients and oxygen.
I'll be using White Labs WLP099 for this one, and the White Labs web site suggests the following:
  • Beers over 16% will taste more like fortified wines than beers.
  • Fermentations will stall in the 12-16% range without the techniques below.
  • Aerate about four times as much as you would for a beer of normal gravity
  • Pitch 3-4 times as much yeast as normal
  • Aerate intermittently during the first 5 days of fermentation. With air, aerate for 5-10 minutes. With pure oxygen, aerate for 30 seconds.
  • Use twice as much nutrient as normal. Higher nutrient levels allow the yeast to tolerate higher alcohol levels.
  • Do not start with the entire wort sugar at once.
  • Start with a wort that would produce a 6-8% beer, then add concentrated wort and/or sugars daily for 5 days, ideally along with aeration.
In a nutshell, my plan is to begin with a yeast starter to grow the yeast population. Then I'll add the yeast to a strong wort to allow it to start going, adding honey or another fermentable until my target ABV is reached. From there, the yeast will be allowed to finish out on its own without further addition of fermentables, nutrients, or oxygen.

Since the goal here is more to see if I can successfully brew a beer that comes out above 16% ABV than to produce the tastiest high-alcohol beer possible, I'm working to keep the recipe extremely simple. If the experiment is a success, I'll consider how to make a more-tasty beer at this alcohol level.

Preparation and Planning

I knew from my reading that this beer would need more attention during the fermentation stage than any previous beer I'd done. I'd need to keep an eye on temperature and gravity, add nutrients and additional fermentables, periodically aerate it, etc. That meant I could only attempt this experiment when I'd be home for a few days to take care of the beer.

I ordered some liquid glucoamylase enzyme so that I would have it on-hand to add to the wort as needed to help with fermentation.

I planned to be home most of the week of Thanksgiving 2018, so I created my yeast starter on Monday evening after coming home from work. It would be ready to use within 12-24 hours. I would brew the beer on Tuesday, and pitch the yeast when the starter was ready. I'd be home for at least the next five days, so I'd be able to keep it on track if need be.

WLP099 Yeast Starter on the stir plate
For the first 24-48 hours of the beer's "life" I would need to keep an eye on its temperature and gravity, so that I'd know when to add more fermentables and yeast nutrient to the fermenter. Once a 67% attenuation was achieved, I could allow the yeast to finish out on its own.

Ingredients

Initial Brew:
3.3 pounds Briess CBW Pale Ale Malt Extract
0.25 ounces Mandarina Bavaria Hops pellets @ 9.2% AA (60 min.)
0.25 ounces Mandarina Bavaria Hops pellets @ 9.2% AA (10 min.)
0.25 teaspoons Yeast Nutrient
1/8 tsp. Brewtan B
1.25 gallons water

Additions during fermentation:
  • 2 pounds honey (0.9 pounds and 1.1 pounds, in two additions)
  • 0.25 tsp. Glucoamylase Enzyme with each honey addition
  • 0.125 tsp. Yeast Nutrient with each honey addition
My goal for the Initial Brew is to hit the following characteristics:
  • BJCP Style: 34.C Experimental Beer (loosely based on a braggot)
  • Batch Size: 1.0 gallons, revised to 1.25 gallons
  • Estimated Original Gravity: 1.126 SG (before additions during fermentation)
  • Actual Original Gravity: 1.139 SG initially. After dilution with distilled water and adding yeast starter liquid, gravity was estimated to be 1.116 SG and volume 1.20 gallons.
  • Enhanced Original Gravity: 1.170 SG (est., after first and second additions of honey and the added liquid volume were considered)
  • Final Gravity: 1.031 SG estimated (before additions), 1.027 SG (after additions)
  • IBU: 38 before additions, 14.4 after additions
  • SRM: 8.2, 8.8 after additions
  • ABV: 10.3% before additions, 18.87% after additions
You'll note that I've decided to ignore one of White Labs' recommendations and start with a wort in the 1.120 SG range. If the experiment fails, I'll plan to do a second experiment and follow that advice.

No mash schedule and no steeping needed for this batch.

Boil Schedule:
  • 60 minutes: 0.25 ounces Mandarina Bavaria hops
  • 15 minutes: 0.25 tsp. Yeast Nutrient
  • 10 minutes: 0.25 ounces Mandarina Bavaria hops and Brewtan B
  • 0 minutes: Turn off induction cooktop and begin chilling
Since I'm not worrying about this beer going into a competition, or even being especially tasty, I've decided to chill it by placing the fermenter atop an old milk crate and placing it outside in the 36F November weather. Since the yeast starter isn't ready yet anyway, the extra elapsed chilling time should not impact the brewing.

Brewing in progress - hops, yeast nutrient, Brewtan B, and fermenter ready

Fermentation Plan

In line with the various recommendations I've read, here's the fermentation plan:
  • Once the yeast starter is finished and the wort is at an acceptable temperature, I'll decant most of the liquid from the yeast starter, swirl the slurry around to loosen it from the beaker, and pitch the yeast into the fermenter. 
  • A magnetic stir bar and Tilt Hydrometer will be placed into the fermenter as well.
  • Instead of an airlock, I'll use a cotton wad in the fermenter at this early stage to filter out wild yeast and allow the free flow of oxygen into the wort and the expiration of CO2.
  • For at least the first 24-48 hours, I'll have the fermenter atop the magnetic stir plate and have the stir plate running to ensure optimal aeration and degassing during the yeast's initial growth.
  • If the temperature gets too high, I'll move the fermenter (and probably the stir plate) outside to make use of the cold ambient temperatures for temperature management.
  • Periodically, I'll stop the stir plate and check the Tilt Hydrometer's gravity readings.
  • When the gravity is down to approximately 1.063 SG according to the Tilt, I'll pitch in a pound of wildflower honey, 0.25 tsp. of glucoamylase enzyme, and another 0.25 tsp. of yeast nutrient and switch the stir plate on for 10-20 minutes to mix in the new fermentables and yeast, and aerate the wort a bit more.
  • I will periodically switch on the stir plate to ensure off-gassing of CO2 and introduction of oxygen to keep fermentation on track.
  • When the gravity drops down to around 1.050 SG, I'll replace the cotton wad with a sanitized airlock filled with distilled water to allow CO2 to build up on top of the beer and prevent further oxygenation. If the beer's still outside at this point, I'll bring it in to let it finish out at ambient temperatures indoors.
  • Once the airlock is on, I'll do no further stirring or oxygenation unless the fermentation seems to stall.
I'm hopeful that this plan will allow the yeast to bring the wort down to at least 1.031 SG. At that point, we should achieve an ABV of 17.85% or higher - making this the highest-gravity beer I've ever brewed.

Post-Fermentation Plan

From what I've read, beers this high in alcohol content typically don't smell or taste particularly great. They often need 6-12 months to condition and improve. That being the case, I plan to extract a small sample of wort after primary fermentation to check aroma and flavor at that point, and take notes. It will then be time to bottle.

I then plan to take some CBC-1 Cask and Bottle Conditioning yeast and rehydrate it. I'll add in some kind of sugar to kick-start it fermenting. While it's activating, I'll get the beer into bottles and add carbonation drops to prime it. Then I'll inject some of this active yeast slurry into each bottle to give the beer the best chance to carbonate. For the first couple of weeks, I'll invert all the bottles daily to keep the yeast and priming sugar in suspension and (hopefully) carbonate the brew.

Somewhere around Christmas, I'll chill a bottle and pop it open to see where it is in terms of carbonation, aroma, and flavor. From there, I'll make a decision as to whether the beer needs to continue to age. I'll also think about what I might change in a "version 2.0" of the experiment. I'll have time in December to brew that one if I choose to.

Post-Brew Notes and Observations

11/20/2018 1pm: The wort came up a bit short in quantity and high in gravity (which I expected), so I diluted it with some distilled water until I hit the target gravity - or at least as best I could measure. The refractometer read in excess of its 1.120 SG maximum, but judging by the position of the line it appeared to be about where 1.126 SG would have been (had it been marked).  I placed the wort outside in the 36F weather to chill to a yeast-safe temperature. When it's within the Tilt Hydrometer's operating temperature range (32F to 185F) I'll use the Tilt to get a "second opinion"... although the Tilt is reportedly only accurate up to about 1.120 SG as well.

The yeast starter won't be ready for at least 8-10 more hours, so my plan is to chill the wort down below ambient room temperature in the basement, then transfer it into the sanitized glass fermenter I'll be using. The sanitized Tilt Hydrometer and a magnetic stir bar will be placed in the fermenter. The yeast will be decanted from the starter and pitched as well.

5:30pm: The wort is down to 62F and registering 1.139 SG, quite a bit higher than we want. The yeast starter was pitched at 11pm last night, so it's been fermenting for about 18 hours now.

8:00pm: Gravity has been registering 1.137 SG since the wort hit a yeast-safe temperature. I added distilled water to bring the gravity down to 1.120 SG. I tried activating the stir plate in the fermenter but failed to get it in the middle of the fermenter (owing to the shape of the fermenter bottom, which is angled away from the center), which prevented it from stirring as it should. I ended up oxygenating the wort with 90 seconds of pure O2 instead.

1:43am: The yeast starter has had plenty of time to do its work, so I pitched it into the wort. The gravity is reading 1.096 SG, but there are clear "layers" in the fermenter so I'm not certain of the exact gravity. I'll now need to increase the amount of fermentables added later to compensate. If the current reading is correct, ABV will be only 9.7%.

11/22/2018 10:30am: Fermentation has been underway for a while now. A curious thing has happened. The gravity initially read 1.098 SG and dropped down to about 1.077 SG during the night. After that, the gravity started to climb and is currently reading 1.093 SG. I took at a look at the fermenter and it's definitely at high krausen now. My suspicion is that when I pitched the yeast starter into the wort, it did not fully incorporate and remained as a layer atop the rest of the wort. This caused the gravity to read lower than it should have. The Brewer's Friend recipe calculator seems to concur with this, suggesting that the gravity (given the ingredients and volume) should have been around 1.105 SG at the start of fermentation rather than 1.098 SG. I'm guessing that the high rate of fermentation is churning up the wort now and mixing it together more, resulting in increased gravity. It may also be that the krausen foam is affecting how the Tilt Hydrometer is floating.

Regardless, later today I plan to sanitize a stainless steel spoon and stir the wort around to keep the yeast in suspension, off-gas some CO2, and better homogenize the wort's gravity. I'll also probably oxygenate it. When I see the gravity reading, I'll decide if it's time to start adding honey to the fermenter. My goal is to add enough to bring the alcohol content to 17% or more.

11:30am:  I sanitized the stainless steel spoon and stirred the wort thoroughly before and after adding 1/8 tsp. yeast nutrient and 1/4 tsp. glucoamylase enzyme. Then I oxygenated it for a few seconds. The gravity reported by the Tilt Hydrometer dropped briefly after the stirring and then continued its climb, eventually reaching 1.100 SG. For about six hours now the gravity reported by the Tilt has been increasing (from 1.077 SG to 1.100 SG as of this writing). Given how quickly the krausen is rising in the beer, I'm guessing that's probably buoying the Tilt a bit and skewing its reading.

12:30pm: The gravity peaked at 1.100 SG (per the Tilt Hydrometer) at approximately 11:45am. It's now dropping back down and is at 1.096 SG as of this writing.

11/23/2018 9:00am: Over the last 28 hours or so, the gravity readings from the Tilt Hydrometer have been moving upward for several hours, then down again. The current reading is 1.062 SG and the temperature is 66F. That equates to roughly 44.8% attenuation and a current ABV of 6.8%. My plan will be to keep an eye on the measurements today. When attenuation reaches 65% or so, I'll crack open the fermenter, add 1.75 pounds of honey, yeast nutrient, glucoamylase, and stir thoroughly to help release CO2 and incorporate the honey, then oxygenate for a minute or two and reseal the fermenter. From there I won't plan to add anything to the wort again until fermentation finishes.

1:00pm: The gravity dropped down to 1.057 SG. I added almost a pound (0.9 pounds) of honey, 0.125 tsp. yeast nutrient and 0.25 tsp. glucoamylase enzyme, and then oxygenated for 30 seconds. Gravity increased to 1.081 SG and the krausen rose back up quickly after the additions were stirred into the beer. Temperature has held at 65F for some time now thanks to the swamp cooler.

9:00pm:  Gravity is now 1.068 SG and the temperature is holding at 65F. By my best guess, this represents approximately 10.37% ABV. We're not yet at my current record (12.84%) or my goal for this batch (16% or higher) but we're getting closer.

11/24/2018 12:00pm:  Gravity is down to 1.058 SG again, which equates to 11.6% ABV and 60% apparent attenuation. It will be time to add another pound of honey soon, so that the beer can achieve its intended 16% or above ABV.

2:15pm: Added 1.2 pounds of honey, a quarter teaspoon of glucoamylase, and an eighth of a teaspoon of yeast nutrient, then agitated everything in the fermenter. The yeast responded swiftly, with a huge swell in the krausen. This is the last fermentable addition I plan to put in the fermenter, but if the yeast is able to consume all this sugar, the beer should come out in excess of 16% ABV.  Prior to the additions, the Tilt registered the gravity at 1.056 SG. After the additions, it's reading 1.073 SG.

5:15pm: The yeast looked like it might be going dormant, with the gravity having dropped to 1.066 SG. Since I'd wanted oxygenate it earlier but did not, I took a moment to give it 30 seconds of O2 to help keep the yeast healthy. The Brewer's Friend ABV calculator offers two different ABV calculations, a "standard" and an "alternate" version intended for high-gravity beers. The standard calculation rates the beer right now as 13.65% ABV (making it the most-alcoholic I've managed to date), while the alternate calculation (which should be more accurate in this case) shows it as 17.56%. If you figure that reality is perhaps a mix of the two, the beer is around 15.6% ABV. That puts it within spitting distance of my 16%-or-higher goal. It's also still got a fair amount of sugar to ferment out before it's finished. It could end up as high as 18.78% according to Brewer's Friend. It's got to ferment another 35 SG points away to reach that.

11/25/2018 11:15am: The fermentation has definitely slowed. It's currently registering 1.062 SG, down from an adjusted 1.170 SG (which takes into account additions of honey in primary and increased volume). The "standard" Brewer's Friend ABV calculation here says that's 14.17% and 60% apparent attenuation. The "alternate" calculator that's said to be more accurate for high-gravity beers like this reports 18.17% ABV. The average of these is 16.17% - which is my goal for the batch.

My plan at this point is simply to keep an eye on the beer and ensure that it continues to ferment. In a few days, I'll transfer it to a clean and sanitized secondary fermenter to get it off any sediment and dead yeast, and let it continue to rest a bit before I consider bottling it.

Given this success (from the standpoint of reaching my ABV goal), I'm already planning another high-gravity brew. The next one is intended to come out in the 15% range and will probably be based on a British Old Ale recipe, with scaled up gravity and bitterness. Or I might aim for a Belgian Quad, scaled up similarly. We'll see.

11/26/2018 8:50pm:  The gravity has been registering 1.061-1.062 SG for a little over 24 hours. Assuming an initial gravity of 1.170 or thereabouts, that's 18.3% ABV according to the alternate calculator on Brewer's Friend.  Tonight I swirled the fermenter a couple of times really hard to help release CO2 and keep the yeast in suspension to see if it would help reduce the gravity any further. So far, it looks like we might have hit the final gravity on this one. I noticed when doing the last honey additions that the Tilt Hydrometer had lots of "gunk" on it, which may be affecting the reading (by making it tilt more or less than it should). We'll see when I have a chance to transfer the beer to a secondary fermenter and (in the process clean up the Tilt).

11/27/2018 9:20pm: The beer dropped to 1.059 SG overnight, which equates to 18.6% ABV. That makes it by far the most alcoholic beer I've ever brewed. I couldn't resist taking a sample of it with a sanitized pipette to see how it tastes. I have to admit that I was surprised. At first, it strikes you as rather sweet and boozy, but almost immediately a hop bitterness comes up to balance that. It's something you're not going to gulp down, to be sure, but it seems quite drinkable already. I'm looking forward to this one finishing out and going into bottles. With a bit of conditioning time, I suspect it could be really good. Right now it comes across as a fairly boozy pale ale with a mandarin orange note malty sweetness.

12/1/2018: Gravity is continuing to drop, thanks to the mix of champagne and WLP099. It's currently registering at 1.053 SG. Brewer's Friend reports that this represents a 19.5% ABV.

12/2/2018: Gravity is now 1.051 SG. Brewer's Friend reports this as 19.81% ABV and 67% attenuation.

12/3/2018: Gravity is now 1.049 SG. Brewer's Friend reports this as 20.1% ABV and 68% attenuation.

12/4/2018: Gravity is now 1.048 SG, 20.25% ABV.

12/5/2018: Gravity is now 1.047 SG. 20.4% ABV.

12/6/2018: Gravity is now 1.046 SG. 20.54% ABV.

12/8/2018: Gravity is now 1.045 SG (20.69% ABV).

12/9/2018: After swirling the yeast around today, the gravity is reading 1.046 SG now.

12/10/2018: Gravity is holding at 1/046 SG.

12/12/2018: Gravity is reading 1.045 SG (20.69% ABV). That's about 6 days now in the 1.045-1.046 range, so it seems likely that the beer has reached its final gravity. I still plan to give it a few more days to see how it goes.

Saturday, November 10, 2018

Christmas Ale 2018

Last year, I brewed a Christmas Ale extract kit from the good folks at Label Peelers. It made a really good Christmas Ale, especially after I dialed down the hops.

This time, I want something more Belgian-like. I'm aiming for a nice malty base with a hint of chocolate. I'll use Magnum hops to bitter it, but Bramling Cross hops for flavor and aroma. Bramling Cross can impart fruity, citrus, blackcurrant, loganberry, gooseberry, and lemon notes to a beer - which I think will blend nicely with the spice mix. I'm planning to use almost the same spice mix as the Label Peelers kit from last year, but doubling the amount of cinnamon stick used to punch that up and dialing back the ginger by half. I'm also adding some nutmeg.

Since I have a packet of Wyeast 3522 Ardennes yeast on hand, I'll use that for fermentation. This yeast is known to produce a balance of fruity esters and spicy phenols which will hopefully go well with the beer. Being a fan of Belgian style beers, I'm curious to see how it will turn out.

Ingredients

7 pounds 2-row Pale Malt
8 ounces Crystal 60L Malt
8 ounces British Pale Chocolate Malt
8 ounces Crystal 80L Malt
0.15 ounces Magnum hops @ 13.5% AA (60 min.)
0.50 ounces Bramling Cross hops @ 6.5% AA (15 min.)
0.50 ounces Bramling Cross hops @ 6.5% AA (5 min.)
1 tsp. Allspice (20 min.)
1/4 tsp. Cardamom, ground (20 min.)
1/4 tsp. Nutmeg (20 min.)
1/2 tsp. Cinnamon, ground (20 min.)
0.65 ounces Sweet Orange Peel (20 min.)
1/8 ounce Ground Ginger (20 min.)
1/2 tsp. Brewtan B (5 min.)
1/2 tsp. Brewtan B (mash)
1/4 tsp. Yeast Nutrient
1/2 vial White Labs Clarity Ferm
1 packet Wyeast 3522 Ardennes ale yeast
3 gallons plus 40 ounces of starting water, carbon filtered

The Picobrew Recipe Crafter estimates that the beer will have the following characteristics:
  • BJCP Style: 30.C Winter Seasonal Beer
  • Original Gravity: 1.082 SG (actual was 1.059 SG, but volume was high)
  • Final Gravity: 1.016 SG
  • IBUs: 20
  • SRM: 27
  • ABV: 8.5%
  • Batch Size: 2.5 gallons (actual was a little over 3 gallons)
Mash
The mash schedule will be:
  • Dough In at 102F for 20 minutes
  • Ferulic Acid rest at 113F for 20 minutes
  • Beta Glucan rest at 120F for 20 minutes
  • Mash at 156F for 30 minutes
  • Mash at 159F for 60 minutes (aiming for a sweeter, full-bodied brew)
  • Mash out at 175F for 10 minutes
Boil Schedule

The boil schedule:
  • 60 minutes: Magnum hops
  • 20 minutes: Allspice, Cardamom, Nutmeg, Cinnamon, Orange Peel, Ginger
  • 15 minutes: Bramling Cross
  • 5 minutes: Bramling Cross and Brewtan B
Fermentation and Bottling

The wort will be chilled using a counter-flow chiller to as low a temp as it can get, most likely around 77F given past experience (note: actual temp ended up being 84F). That's a bit hotter than the yeast cares for, but I'll need time for the package to swell up before pitching it anyway, so perhaps by then the beer will have cooled down. If not, I'll wait for it to get down into the yeast's comfort zone before pitching to avoid generating any fusels.

The fermentation plan is:
  • Days 1-3: Hold at 75F (just under the yeast's recommended upper range)
  • Days 4-7 (or until Final Gravity is reached): Increase to 80F (to encourage ester formation, cleanup, and a finished fermentation)
  • Treat with Biofine or Gelatin Finings and cold-crash 3-7 days
I'll plan to bottle with 5 carbonation drops ("high carbonation") per 12-ounce bottle. I'll bottle-condition it at 76F for two weeks, then allow it to spend additional time at ambient basement temperatures until closer to Christmas.

Post-Brew Notes and Observations

11/10/2018:  I must have measured my starting water wrong. The beer went into the fermenter at a gravity of 1.059 SG, a temperature of 84F, and worked out to a little over 3 gallons in volume.

11/11/2018: It's roughly 14 hours since I pitched the yeast into the wort. Gravity has already dropped to 1.046 SG, representing about 22% attenuation and 1..7% ABV. The blow-off tube is burping CO2 off pretty steadily. The temperature control system has held the temp in the 74-75F range since about 3am when the gravity first showed signs of change.

11/12/2018: We're somewhere around 33 hours since pitching as of this update. Gravity is down to 1.017 SG, which is a point above the expected final gravity for the beer - though with the lower starting gravity I expect it will probably go lower for final gravity as well. In any case, the apparent attenuation at this point is 69.5% and the ABV is 5.4%. The yeast reportedly has an attenuation of 72-76% (depending, of course, on the wort and fermentation conditions) so we may see it go lower.

11/14/2018: Gravity seems to be holding in the 1.015-1.017 SG range, which is right at the expected gravity for the batch. It's been at this range for two days so far.

11/17/2018: The gravity has been holding steady at 1.017 SG, so I decided to bottle it today with four small carbonation tablets per bottle (medium carbonation). The beer is sitting in the 76F "hot box" to carbonate. A sample from the fermenter revealed a thin, mildly spiced beer that was certainly pleasant enough to drink but nothing like I hoped. Most likely that is because the beer came out way below the intended original gravity. I'll need to re-brew to see how it "should have " turned out.

Sunday, November 4, 2018

2018 Pumpkin Ale 1.0

The finished pumpkin ale
My wife and I enjoy a good pumpkin ale. My personal favorite is Hoppin' Frog's Frog Hollow Double Pumpkin Ale. I also enjoy Heavy Seas Great'r Pumpkin (a barrel aged pumpkin ale) and Southern Tier's Pumking. I found a recipe recently that looked promising, so I scaled it down to fit the Zymatic and ordered the ingredients. Tonight, I brewed it.

Ingredients

4.25 pounds of Two-Row Pale Malt
7 ounces of Munich Light Malt
7 ounces of Belgian Caravienne
4 ounces of Carafoam
2 ounces of Biscuit Malt
4.5 ounces of Wildflower Honey added to mash water
15 ounces of canned Organic Pumpkin
0.5 ounces of Crystal hops @ 3.5% AA (60 min.)
0.5 ounces of Crystal hops @ 3.5% AA (20 min.)
0.25 ounces of Crystal hops @ 3.5% AA (10 min.)
5 grams pumpkin pie spice at 20 min.
5 grams pumpkin pie spice at 10 min.
1 packet Safale US-05 yeast
1/4 tsp. Yeast Nutrient
1/8 tsp. Super Irish Moss (20 min.)
1.5 tsp. pH 5.2 Stabilizer in the grain at the start of mash
1.5 tsp. Amylase Enzyme in the grain at the start of mash
1/2 tsp. Brewtan B in the mash
3 gallons plus 16 ounces of starting water with the honey dissolved into it

According to the Zymatic recipe crafter, the beer should have the following characteristics:
  • BJCP Style: 29.B Fruit and Spice Beer
  • Batch Size: 2.5 gallons
  • Original Gravity: 1.060 SG (1.055 SG actual)
  • Final Gravity: 1.008 SG (1.011 SG actual)
  • SRM: 7
  • IBUs: 18
  • Estimated ABV: 6.7% without the addition of pumpkin (5.9% actual)
The mash schedule was configured to:
  • Dough In at 102F for 20 minutes
  • Mash at 113F for 15 minutes
  • Mash at 120F for 20 minutes
  • Mash at 152F for 30 minutes
  • Mash at 159F for 60 minutes
  • Mash Out at 175F for 10 minutes
My goal is a less-fermentable mash and more residual sugar to balance the spice and squash flavors, with an aim toward tasting more like a pie and less like a beer. We'll see how that goes.

The boil schedule will be:
  • 60 minutes: Crystal hops (0.5 ounces)
  • 20 minutes: Crystal hops (0.5 ounces), yeast nutrient, Super Irish Moss, and spice mix
  • 10 minutes: Crystal hops (0.25 ounces), spice mix
The beer will then be run through my counter flow chiller into a sanitized fermenter. It will be chilled further down to the low end of the range for US-05 yeast, then a full packet of US-05 pitched on top of the wort. 

The fermentation schedule will be at least one week at 66F, waiting until the gravity holds at the same figure for 3+ days, at which point I'll add finings and cold-crash the beer for a few days before bottling. 

Post-Brew Notes and Observations

11/4/2018: This is the first time I've tried doing a pumpkin beer in the Zymatic. The style can sometimes be a challenge in a brewing system when canned pumpkin is used, as it is usually finely pureed and can "gunk up" the brewing system if you don't keep an eye on it. I stirred it in with the dry grain prior to mashing and added some amylase enzyme to help convert more of the pumpkin's starches into sugars to aid in raising the gravity of the beer.

Despite adding amylase and pH 5.2 stabilizer during the mash, the gravity on this batch came out about 5 points lower than expected. Wort came out of the counter flow chiller at approximately 77F. I pitched the yeast at that point, directly onto the wort, as 77F is a recommended rehydration temperature for it. However, I've configured the temperature control system to hold the beer at 66F, so it immediately began cooling the beer.

11/5/2018: It's about 24 hours since the yeast was pitched. Temperature has held at 66F. Gravity has dropped from 1.055 SG down to 1.051. That's 7.3% attenuation and 0.53% ABV so far.

11/6/2018: Gravity is down to 1.032 SG. Temperature holding at 66F.

11/7/2018: Gravity has dropped to 1.018 SG. Temperature at 66F.

11/8/2018: Gravity is now 1.014 SG. I turned the temperature up to 70F to help the beer finish out.

11/9/2018: Gravity is down to 1.013 SG. Temperature control was turned off overnight and the beer is holding at 69F. This represents apparent attenuation of 76.4% and ABV of 5.5%.

11/11/2018: While the gravity and temperature have held steady the last few days, there is still an impressive amount of yeast on top of the beer - perhaps between a half and three-quarters of an inch thick (the fermenter in this case is clear so I can see that without opening it). This suggests that the yeast are still active and working, so I am leaving the fermenter alone for a few more days to see if the yeast drops out of suspension. A sample removed from the fermenter showed a good squash aroma with a mild spice aroma. The flavor was good, but I felt like it could use more spice. I'll probably add more at bottling.

11/14/2018: The gravity has been holding very steady now for for several days, so it was time to bottle. Since I'd hoped to serve this at a family gathering next week, I decided to try force carbonating a gallon of the batch to have ready for that, and bottle the rest. The bottles were primed with four carbonation tablets each (medium carbonation). The forced-carbonation vessel was set to 11 PSI to get approximately 2.5 volumes of CO2 in a day or so.

12/13/2018: I was very disappointed with the beer as it came from the mini-keg back at Thanksgiving. Tonight I opened one of the few bottles of the beer and took the photo at the top of this post. Below are my notes in the form of a BJCP scoresheet, treating it as a competition beer.


  • Aroma (10/12): There is a definite pumpkin pie spice aroma with a touch of pumpkin to it. There is a sweetness to it as well. In terms of what I want from a pumpkin beer, this is just about perfect. I'd like to smell a little bit of biscuit or crust here, but it's otherwise perfect.
  • Appearance (2/3): The beer pours a hazy orange color with finger-thick, very creamy, off-white head that lasts a long time. It might be nice if it was a bit clearer, but that's a minor nit. The beer leaves a nice lacing in the glass similar to a Belgian style beer.
  • Flavor (14/20): The flavor starts malty and mildly sweet. The spice and pumpkin come through to a moderate degree. I'd like to see a bit more cinnamon and a touch less ginger, I think, but it's good. The hops presence is just enough to let you know this is a beer, and not a pie, but not so much that it seems like a pale ale the way some pumpkin beers do. I'd like the Biscuit malt to come through more. I might even consider some Victory here instead (or in addition).
  • Mouthfeel (5/5): This has a very creamy medium to full mouthfeel that makes me think of a bite of pumpkin pie with Cool Whip on it. It's just what I would want it to be.
  • Overall Impression (7/10): This is not too far from what I wanted. With less of a ginger note, more of a biscuit note, and maybe a touch less sweetness it might be perfect. 
  • Total: 38/50
Here are the changes I'd make in the next version:

  • Increase the Biscuit malt or Victory malt to 6 ounces, to see if we can bring that flavor out.
  • Drop the mash temperature from 159F to 158F to very slightly dry the beer out without losing too much of the creamy body.
  • Investigate replacing the pumpkin pie spice "mix" with individual spices so that I can alter the proportions to get the spice flavor where I want it, with less of a ginger and allspice note and a bit more cinnamon and nutmeg.