British Yeasts, Fermentation Temps and Profiles, CYBI, Other Thoughts...

[jmo88]

Put very simply: Top pressure is not really an issue with our homebrew setups, 5 gallons of fermenting beer is not going to create enough pressure to slow ester production significantly. Ferment temps, aeration, and pitch rate is way more important. Also, the amount of pressure it takes to push c02 out of an airlock is so small it's really a non-issue. Top pressure is important with large scale brewing since dissolved co2 inhibits, or slows the development of esters and yeast character - think lagers. Open fermentation allows for a greater surface area and more effiecient c02 dispersal in those styles where esters are wanted (thus English, Belgian, German wheat yeasts). Fermenter geometry for 5 gallons isn't going to make a huge difference either.

Homebrewers get benefits from open fermenting with some increased ester production (why and how I don't know - maybe oxygen diffusion?) and the ability to closely control fermentation development. Yeast rousing, top cropping, and easy removal of dead yeast/hop debris before high krausen all lends to a fuller, cleaner, and tastier beer.

There was a member on here regularly a while back that worked with Ringwood in a commercial brewery as their primary yeast. His claim was that it was due to pressure and he thought it carried over to the homebrew realm as well. I agree with you, however, that our situation is much different. Commercial breweries have more of an issue with pressure and that may help them in that regard.

Removing the first krausen layer, may be beneficial. This practice usually goes along with top cropping and open fermentation, so there may be something to that. I believe Kai did an experiment and posted somewhat inconclusive results (braukaiser wiki) on some german beers comparing skimming vs. letting it fall back into the wort.

 

[KingBrianI]

SG for my beer was ~1.014 this morning. Fermentation is definitely slowing down. I gave it a bit of a stir with the wine thief to try to get it to attenuate a little more. At the current rate I'm hoping for it to hit about 1.011 tomorrow morning at which time I'll chill it down. I hope these last couple of points don't take so long that the beer cleans up while it's finishing. I may chill the beer tomorrow morning whatever the gravity may be. It should drop to at least 1.012 by then I expect.

 

[KingBrianI]

I've just realized I could try a few different things with the experimental batch I have going now. I'm planning on kegging the beer, but I have a couple of 5L mini-kegs I might use to test out how casking affects the flavor and maltiness when fermented this way. I was thinking that instead of priming one cask, I would fill it when the beer is 1-2 pts above expected FG. I could also fill the other cask at kegging time and prime that one. I haven't decided what I should do with the casks though. If I add beer to the first one when it still needs to attenuate a couple points, do I crash cool it along with the rest of the beer still in the bucket, or do I store it at 65-68 degrees for a week or two before cooling and serving? There are several things that can be tested with these casks. Crash cool or not, effect of priming sugar, conditioning in the 60s or at serving temps, and differences between naturally carbonated and force carbonated beer. Any suggestions?

 

[poley]

If I add beer to the first one when it still needs to attenuate a couple points, do I crash cool it along with the rest of the beer still in the bucket, or do I store it at 65-68 degrees for a week or two before cooling and serving?

Keep it at fermentation temp for another week or so before crash cooling. The beer will continue to ferment, naturally conditioning the beer in the keg. Just make sure that you are correct about how much further it will attenuate, you don't want to over-carbonate it.

Once you crash it, you'll need to pull a couple of pints off it to get the yeast trub out. Just FYI.

 

[KingBrianI]

Yeah, I've used these as casks before so I know how to do it. My questions is basically should I crash cool the mini keg before letting it warm up to naturally carbonate (I think this is what Fuller's does according to what I remember from the CYBI? interviews), or should I let it carbonate without a cold crash. The idea is to see whether the beer would "clean up" too much by letting it naturally carbonate. I guess I could fill two mini-kegs and cold crash one before carbing, and not cold crash the other. That would show whether the cold crash would lock in the flavors in a naturally carbonated beer or not.

 

[poley]

My recollection was that Jamil recommended just letting the fermentation go to completion w/o any fiddling with the temps. That's my vibe too, and the nice thing about having it in a keg is that you can sample it, and when it tastes how you want it -- crash it.

 

[KingBrianI]

In the rebrew show for Fuller's ESB and London Pride they found that fiddling with the temp was actually the key to getting the right malt expression. The problem with the mini-kegs is that I can't just sample them whenever. Once I open one I have to drink the 5 L in a few days. I'm using them as basically casks. I will have 2-3 gallons in a corny that will be force carbed bu tI'm not transferring the beer to that until after the crash cool and about a week of sitting at 44*F.

 

[flabyboy]

That's one of the yeasts I was very disappointed with. I was expecting that Sam Smith's flavor and ended up with a very clean boring beer. Probably fermented too long and let it clean up too much.

I've been wondering about that too. Casked ale and bottle conditioned beers seem like they would be susceptible to being "cleaned up". Obviously something prevents it since the cask ales and bottle conditioned british beers I've had have been full of that british character. Something else must be going on.

Sam Smith use open fermentation quite a bit. Do you have a spot other than your previously mentioned chamber where you can maintain temps in the low 60 ? I would try open fermentation and see what happens. Not sure if you watch brewing tv from NB, but episode 4 is all about open fermentation. Heres the link

http://www.brewingtv.com/episodes/2010/5/17/brewing-tv-episode-4-open-fermentation.html

Update: should have read the whole thread before posting. Can't wait to see how this turns out

 

[poley]

In the rebrew show for Fuller's ESB and London Pride they found that fiddling with the temp was actually the key to getting the right malt expression.

Ahh. I haven't listened to the rebrew show, since it seemed like fiddling with the temp and the malts/hops were the issue. Guess I'll be doing that soon then

 

[flabyboy]

SG for my beer was ~1.014 this morning. Fermentation is definitely slowing down. I gave it a bit of a stir with the wine thief to try to get it to attenuate a little more. At the current rate I'm hoping for it to hit about 1.011 tomorrow morning at which time I'll chill it down. I hope these last couple of points don't take so long that the beer cleans up while it's finishing. I may chill the beer tomorrow morning whatever the gravity may be. It should drop to at least 1.012 by then I expect.

With open fermentation you need to stir up the yeast a bit. Apparently they are more likely to drop out when they have all that air to breath

 

[jmo88]

There are several things that can be tested with these casks. Crash cool or not, effect of priming sugar, conditioning in the 60s or at serving temps, and differences between naturally carbonated and force carbonated beer. Any suggestions?

Nice that you have those 5L mini kegs. That'll be perfect for experimenting like this. I vote for crash cooling or not. It seems that much of what you have been questioning was the ability to capture this fleeting moment of perfection in the fermentation of these styles. That seems like a good place to start.

 

[bierhaus15]

My questions is basically should I crash cool the mini keg before letting it warm up to naturally carbonate (I think this is what Fuller's does according to what I remember from the CYBI? interviews), or should I let it carbonate without a cold crash.

Fuller's 'matures' its cask beer at 43F before secondary fermentation in the cask with an addition of new yeast. I would give it a go.

Edit: I just went back and listened to both Fuller's CYBI episodes and thought I would post the fermentation profile for easy access. Pitch at 63F and raise to 68F over 8-10 hours, ferment at 68F until 1/2 gravity drops and then chill to 63F. When gravity is 1/4 or 1/5 from target gravity, chill to 43F for 2 days. Rack for maturation, 2 weeks at 50F.

 

[KingBrianI]

Well, just checked the gravity and it hasn't dropped at all from this mornings 1.014. I think chilling to 64 slowed (or stopped) fermentation like I was afraid of. I mashed for 90 minutes at 150 so it really should have a lower FG. Also, I tasted the sample and I think the diacetyl is too high. It's not overwhelming when tasting a small sample, but I think it would be if you were drinking pints of the beer. Now comes the tough decision. Do I warm the beer back to 68 and try to get it to drop some more and possibly clean up slightly, or do I go forward with a possibly undrinkable under-attenuated, overly-diacetyl-y beer in the name of science?

 

[jmo88]

Well, just checked the gravity and it hasn't dropped at all from this mornings 1.014. I think chilling to 64 slowed (or stopped) fermentation like I was afraid of. I mashed for 90 minutes at 150 so it really should have a lower FG. Also, I tasted the sample and I think the diacetyl is too high. It's not overwhelming when tasting a small sample, but I think it would be if you were drinking pints of the beer. Now comes the tough decision. Do I warm the beer back to 68 and try to get it to drop some more and possibly clean up slightly, or do I go forward with a possibly undrinkable under-attenuated, overly-diacetyl-y beer in the name of science?

I thought that's what the mini kegs were for. Rack off some and drop it, rack off another and let it sit or whatever. Maybe I misunderstood what you were planning with these?

 

[flabyboy]

Warm it back up and agitate the yeast. May want to put a lid on at this point

 

[KingBrianI]

I thought that's what the mini kegs were for. Rack off some and drop it, rack off another and let it sit or whatever. Maybe I misunderstood what you were planning with these?

The majority of the beer is going into a normal corny keg and being force carbonated. The mini-kegs would be to test how casking effects the flavors since it was mentioned earlier that if we were chilling the beer right after fermentation to stop the yeast from cleaning up the beer too much, wouldn't the yeast clean up when it was carbonating the cask or bottle? So I was thinking about filling two mini-kegs. One would have been chilled down to 44 along with all the beer going to the corny and the other would have been allowed to carbonate at room temp immediately with no crash cool. That might have shown whether the crash cooling locks in the yeast flavors or whether the yeast would clean up while carbonating the cask despite the crash cool. Now that bierhaus has confirmed that Fullers do indeed crash cool their beer before casking, I don't see the second mini-keg as being needed. I'll still fill one mini-keg to test casking and its effect, but I need this beer to attenuate more first. If it is 4 or 5 points above FG, then I'll have a way overcarbed cask. I'd like to cask at about 1.012.

Warm it back up and agitate the yeast. May want to put a lid on at this point

I agitated the yeast this morning and again this afternoon when I checked the gravity. There is still a bunch of yeast in suspension because the sample was pretty cloudy. But stirring the beer did kick up huge quarter-sized chunks of yeast that had dropped out.

The problem with warming it up is that it would be deviating from the fermentation profile I wanted to test. I think at this point I'll continue to monitor the gravity for the next day or two and if it doesn't drop then I'll consider warming it up. If I did warm it, I would get it up to 58 and as soon as I thought it was done fermenting I would chill it. Hopefully that keeps the malt flavor around that I'm looking for.

 

[elkdog]

What a great thread! I'm especially interested in your experiment, KB, as I just brewed an ESB today based on the malt bill Bob preaches (80% MO, 10% English Crystal, 10% Demerara), and pitched at 63F. It's now rising to 68F, but I wasn't sure yet if I wanted to chill it back down to end fermentation (I'm aiming for an ESB like Fuller's but a bit drier, hence the sugar). I pitched WLP002 from a 1/2 gallon starter, with a hop bill not dissimilar to your Common Room ESB. I'm wondering if cooling it to a lesser extent toward the end of fermentation might preserve the malt character while still getting the diacetyl cleaned up. Following this thread closely, and learning a lot from you folk who've brewed and read more on the topic.

Like a lot of you, I spent time in London not long ago, and want to make a beer that reminds me of the ones I had there, which for my money are the best beers going.

 

[KingBrianI]

Gravity is down to 1.013 tonight and diacetyl has reduced slightly. I'm going to give it another day or two at 64 and hope it drops another point or two. I'd also like the diacetyl to reduce just a bit more. I have to say however, the flavor is really close to what I'm looking for. Really nice maltiness and subtle pleasant esters. I think it's going to be very good.

 

[MuddyMo]

Prost, with extreme prejudice, (for English style ales!)

 

[elkdog]

Gravity is down to 1.013 tonight and diacetyl has reduced slightly. I'm going to give it another day or two at 64 and hope it drops another point or two. I'd also like the diacetyl to reduce just a bit more. I have to say however, the flavor is really close to what I'm looking for. Really nice maltiness and subtle pleasant esters. I think it's going to be very good.

That's exciting to hear. So you're rousing the yeast pretty regularly, then, to get that last bit of attenuation at 64?

 

[KingBrianI]

That's exciting to hear. So you're rousing the yeast pretty regularly, then, to get that last bit of attenuation at 64?

I only roused it the two times. I'm worried about oxidizing it in an attempt to rush things so I'm going to see what it does without rousing. I'll check the gravity again tonight and if it is still at 1.013 I'll give it a gentle rouse.

 

[elkdog]

I only roused it the two times. I'm worried about oxidizing it in an attempt to rush things so I'm going to see what it does without rousing. I'll check the gravity again tonight and if it is still at 1.013 I'll give it a gentle rouse.

Makes sense. Thanks for the updates on your experiment.

 

[KingBrianI]

Gravity is still at 1.013 so I gave it a stir but I'm not sure how much good that will do. The yeast was clumped on the bottom and stirring only brought up big chunks of peanut butter looking yeast that I'm sure dropped right back down to the bottom.

Flavor is becoming very very nice. Great malt flavor dominated by toast and nuts from the amber malt and rich caramel from the crystal malt. Diacetyl was close to yesterday's levels, maybe slighty lower. It really acts to give the beer nice body and mouthfeel while providing a bit of butterscotch to the flavor. It doesn't taste too sweet or underattenuated so I think I will go ahead and chill it down tomorrow even if it doesn't drop another point. I'm hoping the diacetyl continues to reduce, but just a tiny bit. I know the samples taste good, but it's hard to tell what it will taste like when chilled, carbonated and you're drinking a whole pint. I'm afraid the diacetyl which tastes good in the small sample might become overwhelming in a pint. We'll see how it turns out.

 

[elkdog]

It sure does feel crazy to be turning down the thermostat on a a batch with WLP002, but the logic and results are compelling. Nudging it back down...

 

[KingBrianI]

It sure does feel crazy to be turning down the thermostat on a a batch with WLP002, but the logic and results are compelling. Nudging it back down...

With a half gallon starter and 10% sugar I think you shouldn't have a problem with it attenuating or it producing too much diacetyl. Is it first generation yeast? I have a feeling that second or third generation yeast will probably finish quicker than the 1st gen I pitched. For my next batch I'm just going to scoop out however much trub the mr. malty calculator says to and pitch that immediately.

Just out of curiosity, what was the OG and the SG at when you started cooling it for your batch?

 

[elkdog]

The sugar should keep me in good shape, and I went with it because I like the flavor profile of the 002 but didn't want too much sweetness in the beer. This is first generation yeast, and it did start a bit slower than I'm accustomed to. OG was 1.057, and when I turned it down this morning it was at 1.023, so that's already 60% attenuation- probably should have done it yesterday instead, but I forgot to take the gravity last night.
Still hoping to keep the esters around and maybe a touch of diacetyl. I'm bottling this batch, but I think I'll follow through with the Fuller's plan and cool it to 50 when it's down to terminal gravity, as I think that will still leave enough yeast in suspension to carb up my beer, but I'd like to call off the bulk process as much as I can, as it's not throwing many off-flavors at all that I'd want it to clean up. Also not planning to give it the standard 3 weeks in a fermenter. I just don't see the point for these styles, as bitters are best fresh and this yeast is so flocculant.

 

[bierhaus15]

Is it first generation yeast? I have a feeling that second or third generation yeast will probably finish quicker than the 1st gen I pitched.

That's been my experience. Seems the second or third generation has the best mix of fermentation characteristics too; ferments faster, floccs quicker, ect...

A little update: It's been about a week since I pitched some leftover wy1187 for my two (1.25 gallon) test batches. The gravity has gone down from 1.045 to 1.010 for both and each was fermented at 68. My taste buds are somewhat shot due to a cold, but both samples tasted very nice. There is some diacetyl in the samples, though at appropriate levels. I will let them sit at 68 for a couple more days, then crash cool one to 43F for a few days with the other sitting at room temp. Should give me an idea what effect crash cooling has on the malt profile once fermentation is over.

 

[bierhaus15]

The sugar should keep me in good shape, and I went with it because I like the flavor profile of the 002 but didn't want too much sweetness in the beer...I'm bottling this batch, but I think I'll follow through with the Fuller's plan and cool it to 50 when it's down to terminal gravity, as I think that will still leave enough yeast in suspension to carb up my beer

Just a word of warning: If you really are planning on bottling this batch, I would make sure your final gravity is low enough to ensure the yeast don't reactivate once in the bottle. This yeast is notorious for going dormant in the fermenter only to 'wake up' after bottling, eating both the priming sugar and residual sugars in the beer; producing an over-carbonated, cidery taste. I've seen this happen soo many times, both in my own beers and while judging. For that reason, I rarely bottle carbonate beer fermented with this yeast. If I absolutely have to do it, I will crash cool the beer to near freezing as to flocc as much of the yeast out and then bottle using some US-05. It doesn't always happen, but just be aware that it might.

 

[elkdog]

Just a word of warning: If you really are planning on bottling this batch, I would make sure your final gravity is low enough to ensure the yeast don't reactivate once in the bottle. This yeast is notorious for going dormant in the fermenter only to 'wake up' after bottling, eating both the priming sugar and residual sugars in the beer; producing an over-carbonated, cidery taste. I've seen this happen soo many times, both in my own beers and while judging. For that reason, I rarely bottle carbonate beer fermented with this yeast. If I absolutely have to do it, I will crash cool the beer to near freezing as to flocc as much of the yeast out and then bottle using some US-05. It doesn't always happen, but just be aware that it might.

Thanks for the tip. I've used this one before, but never in conjunction with cooling it like this. I've got some S-05 on hand.

 

[KingBrianI]

My batch still had a gravity of 1.013 so I set the temp to 44 and it's chilling right now. Diacetyl had reduced slightly again and hopefully is at a good level right now. I hope I'm not one of the people who is relatively insensitive to it and that this beer tastes like butter to everyone else! I'm so pleased with how the malt is coming through though. It is really amazing how a beer can taste this layered and complex now, but if left on the yeast for a couple more weeks would be flat and boring by comparison. If I continue to have success with this method, I'm definitely going to have to start challenging the current knowledge that beers taste better after 3 weeks in primary (at least for British ales). Now, to perfect my late hop technique and I'll be turning out british ales I can really be proud of.