WLP 037 Yorkshire Square Yeast Results

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Sep 9, 2013
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So, I finally got around to using this yeast in my ESB. I've been anticipating doing this beer since I got this yeast almost a year ago, since it's my house beer, and it's a yeast I've been waiting a long time to use. I really, REALLY, wanted to like this yeast. I wanted to fanboy all over the place and tell all the other posters with less than ideal results how this yeast is a diamond in the rough and with proper technique it really shines.

I cannot do that.

So here is the down and dirty on WLP 037 from my perspective.

1. Holy clove flavor, Batman. I had read a couple comments from people getting clove flavor and thought that with proper pitch rate, oxygenation, and temperature I could avoid the clove. I failed. I did a two-step starter (since the yeast was 9 months old when I began the starter) with the first step a 1.030 2L starter, and the second step a 1.037 5L starter. I overbuilt to save a bit of yeast for later. According to the Beersmith calculator (and every other online calculator I consulted) I was a good 10-20% higher than required. I oxygenated with pure O2 and a diffusion stone for more than a minute in each of the 5G carboys. For temp, I started a bit low at 63°F until 24 hours after I had a solid yeast cap. I then slowly raised the temp 1°F per day, eventually getting it up to 72°F for a diacetyl rest. After a week at 72°F I dropped the temp to 50°F for three weeks while I was out of town. Good news. No diacetyl to speak of. Bad news: clove-o-rama, baby. For all those trying to maximize clove flavor in your hefes, might want to mix in a bit of this stuff because you cannot not get clove with this stuff - at least not in my limited experience. And the warmer it gets, the more pronounced the clove flavor is.

2. Attenuation. I read a lot about under-attenuation and was not super concerned, since I like my beers malty and I like this particular ESB a bit sweet. The Gambrinus ESB pale malt really shines with a little extra sweetness so I wasn't concerned about starting a little lower than recommended (recommended low temp is 65°F according to White Labs). Yeah, about that... my final gravity was 1.002. I triple checked with three different hydrometers. Perhaps I had some old diastaticus somewhere in my system. But my cleaning regimen is pretty solid (hot water PBW, healthy scrub, hot water rinse, Star-San spray down prior to transfer) so I don't think that's the case. I've never had an issue like this before, and it happened in two different carboys. Plus, the last yeast I ran in these carboys was Imperial Yeast's "The Darkness" which is VERY similar to WLP004 and has no history of diastaticus related issues. I did not rouse the yeast. I didn't add any amylase. Remember, I was TRYING to have this come out a bit high in the gravity department. My mash temp was right at 154°F and I only mashed for just over an hour.

That's the main points on the bad.
Here's the good:

3. Flocculation: This stuff drops like a rock. After moving my carboys from the fermentation chamber to the counter for transfer, the yeast dropped out of suspension within a couple minutes. Then, when I was transferring the beer to the keg I barely got any sediment drawn up. I ended up putting this in two kegs, and within the first glass on both kegs, there was no sediment left. And once it was in the glass the sediment dropped to the bottom and stayed there.

4. It has a nice head. Like, super creamy Guinness-style head and I'm not running this through a creamer faucet or anything.

So there you have it. My take on WLP 037. I wanted to like it. I took my time and did my research. I had a good brew day with no immediately obvious mistakes. So now, please, tell me what I should have done. I've got some yeast saved in the fridge and am willing to take another shot at this.

The recipe
Bit R Done
OG 1.052
Batch Size 12G
FG 1.002

19lb 5oz Gambrinus ESB Pale Malt
1lb 5oz Caramunich

1oz Chinook (12.8% AA) @ 60min
1oz Fuggles (4.2% AA) @ 20 min
1oz Fuggles (2.9% AA) @ 10 min

WLP 037 Yorkshire Square Ale Yeast
500 billion cells

Calcium 51ppm
Sulfate 103ppm
Chloride 14ppm
(This is my "high bitterness" water mix for my ESBs.)

154°F for 60 minutes

60 minute boil. I added Irish Moss and 2 tsp of Yeast Nutrient at 10 minutes remaining in the boil. Immediately chill to ground water temp and put in the fermentation chamber to get down to 63°F and stabilize.

63°F until yeast cap formed for 24 hours, then raised temp 1°F per day to 72°F. Held temp at 72°F for a week, then dropped to 50°F for three weeks.



Well-Known Member
Aug 4, 2008
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Nice summary. I have not had much luck with that yeast as well, although I am tempted to try it with a proper rousing schedule during the first 48-72 hours of fermentation. The rousing increases diacetyl production and softens the overall profile; both characteristic of the "northern flavour." Also, some Yorkshire producers ferment their beers quite cool (60-62F) and that may help with the clove reduction.


I'm not Zog
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Sep 12, 2014
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sf Bay Area
I only used wlp039 once and my results were pretty much in line with yours. I plan to circle back to it some day but I have other better behaved yeasts to circle back on too so it might be a while.

If clove/phenolic is not pleasant to you, probably steer clear of wlp038 Manchester ale. Recently used it to brewed a best bitters in the mid to upper 60s and it had a pretty strong clove phenolic aroma and flavor on kegging. There might of been an apple or pear like flavor too, I will check it in few week to see if it has mellowed. I did not rouse it just 3days at 67 and 5 days at 70 and it had a relatively low attenuation of 68% with a 152F mash. It did dropped like rock, and transferred clear to the keg.