Advice for Kölsch-style fermentation schedule?

[Nava854]

At this very moment I’m fermenting my first batch of Kölsch-style beer. I’m using the WLP029 yeast.

I pitched at 16C (61F) and let it ferment at that same temp. It went from 1.048 to 1.013 in 2½ days and it seems to have passed peak fermentation (krausen has collapsed and airlock does not bubble as much) so I raised temperature to 18C (64F) to prevent fermentation from stopping (according to White Labs info). Gravity is still dropping right now, but very slowly.

My current plan is:

• Keep wort at 18C (64F) up to a week after fermentation is done.
• Maybe do a diacetyl rest at 21C (70F).
• Then lager at 1C (34F) for 4 weeks in primary.

I have many questions but the main ones are:

• How long do you think I should leave the wort at 18C (64F) after SG stops dropping? Could I leave it for 2 weeks instead of 1?
• Should I do a diacetyl rest? I don’t even know what diacetyl tastes like.
• Should I rack to a secondary before lagering? I’ve heard that it’s best to leave it in primary but I’m not sure.

I’m still a very inexperienced brewer and I fear I am being too ambitious with this batch. Any help or advice will be appreciated!

 

[VikeMan]

How long do you think I should leave the wort at 18C (64F) after SG stops dropping? Could I leave it for 2 weeks instead of 1?

If you're planning to do a diacetyl rest, there's no reason to leave it at 18C for even one week, In fact, you can start ramping up to your diacetyl rest temp toward the end of fermentation. If you're not planning to do a diacetyl rest, a couple weeks at 18C wouldn't hurt much, but really isn't necessary. If you are at final gravity and there are no off flavors, you can move on.

Should I do a diacetyl rest? I don’t even know what diacetyl tastes like.

Diacetyl tastes like popcorn artificial butter or butterscotch. It also has a slick mouthfeel. Even if you don't taste it now, it could be produced later. In that case, a diacetyl rest is good insurance.

Should I rack to a secondary before lagering? I’ve heard that it’s best to leave it in primary but I’m not sure.

Are you bottling or kegging? I lager my lagers in the serving keg. When finished, the first pint or two will be cloudy (with a normal dip tube) or not (with a floating dip tube). But if I were bottling, I would at least cold crash the primary (but keep O2 out) before bottling. You can "lager" in bottles, but whatever drops out of suspension will be stirred up to some extent when you pour.

 

[dmtaylor]

You won't need a diacetyl rest with this yeast. It really is very clean and just does not produce diacetyl that I have ever experienced from my brews or my friends' brews.

You won't need a long lagering period with this yeast either.

I think you can leave it for a week warm just to ensure fermentation is complete, that is fine, then chill for like one week for lagering. But beyond that, the benefits if any will be undetectable. The beer is honestly almost ready to drink right NOW. It will clean up really fast and be totally ready in just a few days.

This is all because of your choice of yeast, WLP029 is just very fast and clean. You might have different results from different yeast strains. If you had instead used Wyeast 2565, which is a completely different yeast altogether, then all the extra time would be necessary, and then some. Wyeast 2565 is an extremely stubborn yeast that takes 5-6 weeks to finish and settle out. You might have seen guidance on Kolsch beers due to this latter yeast strain, which is totally different from WLP029.

 

[monkeymath]

I have no experience with Kolsch or with that yeast strain, but I generally consider a dedicated diacetyl rest unnecessary if you keep the beer at 'ale fermentation temperature' or above for some time.

I have a beer fermenting with WLP 029 right now (at 17.5C). I won't cold crash it, simply because I have no means of keeping oxygen out while doing so (and improved clarity is not worth staling). So I'll just leave it at that temperature for a week after fermentation has died down (which is about now) to give the yeast some time to settle before I go ahead and bottle. I'd like to be able to lager in the fermentor, but imho the effects are often overstated.

 

[Nava854]

Thank you for the replies. As a beginner, I cannot overstate how invaluable your opinions are to me.

I think it will be easier for me to just let it sit at 18C for 7 days just for peace of mind and be sure fermentation is complete, and then skip the diacetyl rest.

I'll be bottling so I will just lager in bottle. I am using a plastic bucket as the fermenter and I didn't realise how permeable they are to O2 until now, so lagering in it would be a bad idea. And moreover, after reading this Brülosophy experiment it seems that cold crashing in primary is not as effective as people may believe. I will resort to just using gelatine and bottle without cold crashing.

 

[Jag75]

I tend to lean on the ole " err on the side of caution " personally. I always let fermentation temps rise towards the end. Never had a diacetyl problem yet .

I'm set up for cold crashing but don't do it much at all. I cold crash in the kegs . You can lager in bottles . Its really just conditioning at cold temp

 

[monkeymath]

I am using a plastic bucket as the fermenter and I didn't realise how permeable they are to O2 until now, so lagering in it would be a bad idea. And moreover, after reading this Brülosophy experiment it seems that cold crashing in primary is not as effective as people may believe. I will resort to just using gelatine and bottle without cold crashing.

If you're bottling, then diacetyl needn't be a concern at all, as you'll keep the bottles at room temperature for a week or so to carbonate anyways. If you manage to actually preserve diactetyl beyond that point, I am going to need detailed notes of your process - I'd love to trap some diacetyl in a Czech pilsner, but haven't managed to so far.

It is not so much the oxygen permeability of the bucket per se, but the amount of air sucked in when lowering the temperature (because the bucket's content contracts), that keeps me from doing a coldcrash. Some people have devised rather simple solutions using balloons and the gas produced during fermentation to mitigate the issue, but I haven't tried those yet.

By the way, I'm afraid gelatin will not do much at this temperature. The main culprit of haze is only formed at lower temperatures, and the gelatin cannot drop it out unless it's already there (sorry, language barrier - I can't find the right word for it).

 

[Immocles]

If you're bottling, then diacetyl needn't be a concern at all, as you'll keep the bottles at room temperature for a week or so to carbonate anyways

I never considered that carbonation time would eat up diacetyl.

 

[Nava854]

If you're bottling, then diacetyl needn't be a concern at all, as you'll keep the bottles at room temperature for a week or so to carbonate anyways. If you manage to actually preserve diactetyl beyond that point, I am going to need detailed notes of your process - I'd love to trap some diacetyl in a Czech pilsner, but haven't managed to so far.

It is not so much the oxygen permeability of the bucket per se, but the amount of air sucked in when lowering the temperature (because the bucket's content contracts), that keeps me from doing a coldcrash. Some people have devised rather simple solutions using balloons and the gas produced during fermentation to mitigate the issue, but I haven't tried those yet.

By the way, I'm afraid gelatin will not do much at this temperature. The main culprit of haze is only formed at lower temperatures, and the gelatin cannot drop it out unless it's already there (sorry, language barrier - I can't find the right word for it).

I see... Really good info here.

For the record, we were planning on using a mylar balloon filled with CO2 and attaching it to the airlock, but it seemed to much hassle so we just ditched the idea of cold crashing. But the thing is I already have the balloons and the CO2 canister, so if my dad and I feel like it we may give it a shot, who knows.

And don't worry, I understood what you meant about the gelatine. I need to bring the nasty stuff out of suspension by lowering the temperature before the gelatine can even do something about it.

Thanks, very informative!