Darkness by Imperial - Early Thoughts

vthokiedsp

vthokiedsp

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I've noticed that there isn't a lot of empirical / anecdotal information about experiences with the Darkness strain by Imperial. So, figured that I'd share some of my early experiences and continue to add to what I'm observing.

I brewed an oatmeal stout yesterday morning with a grain bill of 50% maris otter / 10% flaked oats / 9% each of victory and pale choc / ~5% each of C60 and midnight wheat. cascade and willamette for slight bitterness and complexity and a late addition of fuggles for dirt (IBU ~34). targeted 1.062 OG, hit 1.064 OG with a 90 min mash @ 1.6 qts/lb. conversion was stubborn but it got there somewhere between 60 and 90 mins.

local brew store didn't have the wyeast 1084 (irish) and i've been underwhelmed by WLP (too much fruitiness in their strains, even at lower temps) so i decided to go with Imperial's Darkness. 200B cells versus 100B which was a better pitch fit for my OG and volume. The temperature range 62-72 was much more flexible than the WLP equivalent (65-68). $2 more than WLP pack and $3 more than wyeast but i only had to purchase one pouch so it was really a savings in the end.

cooled wort to low 60's. poured about 1.5 gallons of wort through a brew bag to aerate and then pitched the yeast. yeast instructions said to store cold/pitch cold but i noticed that a little late and had the pouch at ambient (68 deg F) for a couple hours. aerated/swirled for a minute or two and then added the rest of the wort through the same brew bag for more air entrainment. Pitch time was around noon.

moved wort to a room where the ambient temp was in the upper 50's so i added a small heat pad w/ temperature controller to bring the temperature back up to 62 deg F. when i checked on things this morning at 7:30 am (not even 24 hours later), a 1.5" to 2" layer of krausen had formed and bubbling activity was steady in the blowoff bucket. Temperature had risen to 66 deg F. The sensor is taped to the exterior of the glass carboy with some insulation to isolate the cool ambient air.

Compared to my experience with WLP yeasts, the early activity at the lower range of the temperatures is a welcomed site. Previous ferments with WLP have taken 36 to 48 hours to achieve this level of fermentation when starting in the low 60's.

Like I said, these are my experiences early on in the process so far and I'm looking forward to seeing what the flavor profile will be. So far, so good. I'd be interested to hear what others have experienced with Darkness (e.g. ester/phenol balance, malt/hop accentuation, etc).
 
Update:

Darkness ripped through fermentation in about 3 to 4 days. I dont pull gravity readings until i rack to my bottling bucket but based on activity, thats what i observed. Krausen completely dropped at 4 days. Clean smells from blowoff bucket....which i didnt need. A regular airlock would have been fine as the krausen didnt even come close to coming out of the carboy. I have 4.25 gal in a 5 gal carboy. It had a very mild krausen development when compared to San Diego Super.

At peak fermentation, temps ramped to 68 degrees in an ambient room of 62 to 64 degrees. 68 is still well within the range (up to 72). Itll be interesting to see what flavors developed at 68. Hopefully not too much fruit.
 
vthokiedsp said:
I dont pull gravity readings until i rack to my bottling bucket.
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Do you check the gravity before the priming sugar is in? Seems like that’d give you a false reading.
 
jeffpn said:
Do you check the gravity before the priming sugar is in? Seems like that’d give you a false reading.
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I pull my sample while racking to the bottling bucket. It has not mixed with the priming sugar yet. My schedule is always two weeks in the primary so there is no point in pulling any samples while in the primary. Its an unnecessary risk imo and a pain quite frankly, even with a thief. The fewer the sanitization activities throughout the process the better.
 
Gotcha. I put my sugar solution in the bottling bucket and then rack on top of that. That’s why I asked. I guess it didn’t occur to me that you would divert the flow for your hydrometer, even though I do the same thing when I rack from primary to secondary!
 
jeffpn said:
Gotcha. I put my sugar solution in the bottling bucket and then rack on top of that. That’s why I asked. I guess it didn’t occur to me that you would divert the flow for your hydrometer, even though I do the same thing when I rack from primary to secondary!
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Sometime i rack on top of the sugar solution, sometimes i pour the solution into the filled bucket. Ive found that mixing throughout the bottling process (every gallon or so) helps with more consistent carbonation. First few brews i had some bottles that were more carbed than others.
 
vthokiedsp said:
I've noticed that there isn't a lot of empirical / anecdotal information about experiences with the Darkness strain by Imperial. So, figured that I'd share some of my early experiences and continue to add to what I'm observing.

I brewed an oatmeal stout yesterday morning with a grain bill of 50% maris otter / 10% flaked oats / 9% each of victory and pale choc / ~5% each of C60 and midnight wheat. cascade and willamette for slight bitterness and complexity and a late addition of fuggles for dirt (IBU ~34). targeted 1.062 OG, hit 1.064 OG with a 90 min mash @ 1.6 qts/lb. conversion was stubborn but it got there somewhere between 60 and 90 mins.
Click to expand...

Racked for bottling last night. FG was 1.015. Apparent attenuation was 79%. Imperial Yeast's website publishes 71-75%. With a 154 def F mash, I'm impressed with the attenuation and FG (0.002 less than predicted). I fermented at 67 deg F which is pretty close to the middle of the published ideal range (62 - 72). At peak fermentation, temps got to 68 deg F (ambient was around 62/63). When I tasted the FG sample, I noticed very very subtle fruit flavors. Malt flavors popped. It'll be interesting to see what a few weeks of bottle conditioning does for the flavor profile.
 
Nice.
 
Update:

I collected the Darkness yeast slurry from the oatmeal stout and pitched it into a blonde ale wort (1.040 OG) two weeks after collecting it. The darkness slurry ripped through the wort in about 3 days. The krausen layer for this yeast is not very deep and dissipates quickly. Fermentation was done in 5 days but I let it sit in primary for 2 weeks. Ramped temp from 65 to 70 after day 4. I used Mr Malty to determine the amount of yeast slurry to pitch.

Racked to kegs last night and took a FG of 1.006 (apparent attentuation of 85%). Looks like Mr Malty nailed the pitch.

As far as flavor from the yeast, it was very clean at the temps I fermented at. Like with the stout, it had a very subtle fruity character. It really let's the grain and hop bill shine. Because my stout was was dark, it was hard to tell how flocculant Darkness is but with the blonde, you could tell that it's not a high floc yeast that will produce a very clear/bright beer, even with a cold crash and gelatin fining step. Haze doesn't faze me at all though.

All in all, I plan to use to Darkness in the pitch pouch format for any beer that I want the malt and hops to shine, and clarity isn't a requirement. Very good yeast with a forgiving temperature range during ferment. Attentuation in the 80's for a yellow beer was great (batch sparge). Close to 80 for a stout was great as well. I'd def recommend giving it a shot, esp if you're sick of wlp001.
 
Completely off topic, but all I can think of is that chappelles show sketch with Charlie Murphy and rick james
 
yep it sure does sound like the GO at 200 billion cells theyre a great pitch straight out the can/pouch. its not available to me yet in Aus but in time im sure itll pop up around the place over here. unless some Aussie yeast mob starts making their own then id be sure to buy them...
 
Yeah I haven't found them in Canada either. Going to try the Wyeast Denny's favourite 50 next.
 
Trialben said:
yep it sure does sound like the GO at 200 billion cells theyre a great pitch straight out the can/pouch. its not available to me yet in Aus but in time im sure itll pop up around the place over here. unless some Aussie yeast mob starts making their own then id be sure to buy them...
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200b cells is perfect. Cheaper than any liquid yeast per 100b cells. If you recover once, it's down to $2.50 per 100b.
 
Hawkbox said:
Yeah I haven't found them in Canada either. Going to try the Wyeast Denny's favourite 50 next.
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Where do you live in Canada? Compromising border security if one of my fav past times and I'll be near kingston in late July.
 
I live in Edmonton, northern Alberta. So not quite an easy trip.
 
Essay incoming:

Seemed like this would be the best thread to add on to for my situation. On Monday I brewed 10 gallons of a brown that I intend to add maple syrup to, once primary has completed. I hit 1056, which was right around target, cooled almost perfectly down to about 70F, and pitched two packets of Darkness into separate SS 7.5 gallons conicals, each filled with 5 gallons of wort. This was around midnight, the following morning at 10am I already had some airlock activity. By that evening it had free risen to 72F, in a room of about 66F I believe, and was going pretty hard. I was able to turn on the ac and add ice packs to keep it between 71F-72F. Ideally I would have had it below 70F for the start of fermentation, but my basement was being worked on for a couple days. I left it unattended over night, for about 8 hours. When I checked Wednesday morning it had risen all the way up to 74F, unsurprisingly my roommates turned off the ac (cause it was admittedly freezing). My guess is it was only at this temp for maybe 6 hrs max. I promptly moved them down to my now available basement and they chilled down to 71F within a few hours, and have maintained there with the help of the regulated heating pads. They have since slowed down considerably, I hope I'm not stressing the yeast by the temp change, but it's also possible that they ripped through a lot of sugar in a short period of time. I'm curious to see how much fruit/esters I get, it doesn't list that as a normal flavor, but going a little bit over temp range is obviously concerning. I don't think it will be a huge deal as I used to leave beers in room temp environments all the time and it was only recently I got meticulous with my conicals. Cheers
 
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Lucky for you it was a darker beer but ive found using a ferm chamber I'll only hold the temp a day or three then start bumping temp so I'm reckoning as long as you had it at recommend pitch temp for atleast the start of fermentation you might find you'll have a lovely beer to thankyou for it:rolleyes:.
 
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