I’m having some trouble with English ale yeasts fully attenuating. I have an oatmeal stout, OG 1.050 that will not ferment below 1.020. It is mashed at 152, pH 5.40, fermented with 2 liter starter wlp002.
BCS brown porter mashed at 153, pH 5.40, 1 packet rehydrated S-04 yeast, OG 1.054, FG 1.022
BCS mild mashed at 152, pH 5.33, 2 week old vial wlp002, OG 1.038, FG 1.016
MO smash mashed at 152, pH 5.21, 2 liter starter wlp 002, OG 1.050, FG 1.020
My basic process for all: thermometer, pH meter, scale, refractometer, volumes are all calibrated. Mash time is 75 minutes, 60 minute boil, chill to 66f in ~15 minutes, oxygenate 60 seconds, pitch and allow to free rise to 68f, hold fermentation temperature at68 until fermentation activity begins to slow and raise temperature to 72 while rousing yeast twice a day until fermentation activity ceases.
I generally have no problem with my American ales fully attenuating, even big beers. But the English ales have been rather frustrating. I will try a fast ferment test on my next batch. Why can I not achieve better than 57-58% attenuation with English yeasts?
wish i could say its the english yeast, but ive not had any issues raching target FG. when i have had issues in past with FG, its not yeast specific- its one or combination of amount of healthy yeast, wort oxygenation, mash PH, mash temp, or fermentation temp (too low).
I am measuring FG with a hydrometer which measures 0.000 in RO water at 60f. Readings are adjusted for sample temperature.
To add, my yeast starters are made on a stir plate. I am rather anal about freshness, especially when it comes to yeast. Starters are within a few degrees of wort temperature at time of pitching. I really enjoy the flavor profiles of English yeasts, especially wlp002, but I’m getting quite tired of drinking under attenuated beers. If I don’t get this figured out within the next few batches I may be forced into an American revolution!
Understand your frustration. I will say with 100% certainty it’s not the yeast strain at the root of your problem. Something else as I indicated must be going on.
I feel your frustration believe me i do. It ended up being my thermometer, even though i calibrated it ! i ended up buying a new one and it fixed the issue. i will say i am just not a fan of 002/1968 just because it takes some pampering, it is really fickle on “my system”. i have moved to west york 1469 for most of my english and love it. Good luck and let us know
If you are comparing Bry 96 (a.k.a. Ballentine “Beer”, “Chico,” 1056, WLP001, US05 …) to English strains, then you need to re-frame the problem. Bry 96 is an incredibly forgiving, almost stupid proof yeast strain. On the other hand, English strains can be anything, but stupid proof. The number one reason why English strains fail to attenuate properly is lower than required dissolved O2 at the beginning of fermentation, especially highly flocculent strains such as WLP002.
OK so my oxygenation process is as follows: I use the little red O2 bottle with an oxygenation stone. I place the stone on the bottom of the carboy and turn on the gas, not full blast, but just until O2 is coming from every pore on the stone. Leave it on for ~60 seconds. Yeast is then pitched immediately. This has given me the same % attenuation regardless of starting gravity. How might I improve upon this? Crank up the gas to full blast? Oxygenate longer? Stir or shake while oxygenating?
Also I suspect a thermometer issue. I do not wish to purchase yet another new thermometer at this time, nor do I wish to enter a discussion on calibrating at mash temps so I will try mashing lower next time- maybe 147f.
…because they’ve been using 15-25% adjuncts in all their beers for the past 100 years!! It’s as if they’ve steered natural selection to attenuate poorly. Eat nothing but Big Macs for a month and see how healthy you turn out!
That’s my theory which is also based on fact.
Do as the English would do… add a whole bunch of simple sugars, or change your yeast, or both.
ya again i feel ya yet another thermometer:) i mashed lower also it helped but it did change the “character”/thinner mouth-feel of the beer in my eyes. I love the Big mac analogy
None of the recipe’s I’ve seen from Fullers call for simple sugar additions. The malt bill for ESB (from the brewer) is 93% Pale Ale Malt, and 7% Crystal malt. I’ve never had an underattenuation issue with 1968, even in bigger, all-malt brews.
Interesting theory, but I’m not convinced. There has to be something else.
I’d suggest the OP mash a full 90 minutes and definitely recalibrate the thermometer. I’ve had attenuation issues with English yeasts as well. But I think that was mainly because the fermentation temperature wasn’t as warm as it needed to be for long enough. It would reach 68 during peak of fermentation, but drop down as fermentation was winding down. I think this hurts attenuation. I try not to brew with English yeasts during the colder months when I don’t have a way to keep the beer warm.
My first reaction was to suggest ramping up after a few days, because 1968 likes to floc out early. But you’re doing that. Limiting crystal malts would help to an extent, but it sounds like thermometer accuracy could well be the culprit.
On calibrating my thermometer, it’s been calibrated in an ice water bath at 32.0f. But it reads 208.6 in boiling water at 2000’. Boiling water should be 210f at my altitude, right? This is the thermometer I use: Shop - Products - Pocket Digitals - ThermoWorks. I’m not sure 1.4 degrees would make that much difference in fermentability. I’ll try a longer mash time if it can improve fermentability but according to Braukaiser’s chart, I am achieving damn near 100% conversion efficiency.
On limiting crystal malts, I’ve had the same results with a SMASH beer.
As far as using simple sugar, it’s not off the table but but I would prefer to earn my English ale merit badge without it. If others can achieve satisfactory results without it, I should be able to as well.
Maybe I’m the English yeast whisperer or something, but I’ve never had a problem with flocculant English yeasts at low temps. I tried to cold crash a starter of 1968 after about 20 hours a few months ago and I couldn’t get it to drop even at 45F in the fridge. Last winter I had the Yorkshire Square strain (which is so flocculant it makes 1968 look like a weizen yeast) take an all-malt barleywine from 1.142 down to 1.024. It was fermented at 58F for the first week before bringing it to the mid-60’s to clean itself up.
Other thoughts (although just grasping at straws, mainly)
Try bigger starters to see if that helps.
Try pitching your starter at high krausen (or shortly thereafter).
Repitch and see if things improve on a further generation.
Well I brewed my oatmeal stout and used almost everyone’s advice in my quest for better attenuation. I know, I should change one part of my process each time I brew so I will know what works. But I would rather not drink another underattenuated beer. Here’s where I made adjustments:
Grist: I actually used more crystal malt, from 3% up to 5%. I decided to try Golden naked oats for the first time and subbed it for crystal 80. The raw grain had such a nice sweet oat flavor I couldn’t help myself. I also subbed in 5% cane sugar.
Mash: lowered temperature to 150 and mashed a full 90 minutes. Lowered pH to 5.25.
Yeast: WLP002. Used 7 ounces of thick slurry from a mild brewed 10 days ago. The slurry and a quart of wort went into a carboy for 90 minutes, swirling periodically until it began to foam. The rest of the 64 degree wort was racked on top.
Oxygenation: 90 seconds pure O2 while rocking carboy.
Fermentation: temperature allowed to rise to 68f and sporting a good krausen at 12 hours.
I fully expect better attenuation on this one. If it ends up too dry I’ll make adjustments one thing at a time on successive batches, but at least I won’t have to drink another under attenuated beer!
The only thing that sticks out is that you used yeast from a previous batch which may have been under attenuated. Wouldn’t that yeast have been already bred to drop out?
I did consider this.
The yeast in question was a vial of wlp002, bought from my lhbs fresh off the UPS truck in winter shipping conditions, and pitched into 5.25 gallons of 1.038 wort @ 2 weeks past the yeast’s production date. This should pretty much eliminate the yeast as a variable, for this batch. Attenuation aside, I couldn’t imagine a better pitch for my stout. So what are the odds that the variable(s) that caused the under attenuation caused a full genetic adaptation to those conditions in just one generation? I’ll take my chances but I won’t rule it out in the event of a failure.