First Lager - Oily Slick Mouth Feel

[RiderEh]

So I'm guessing I have diacetyl. Here's the breakdown:

Brew House Pilsner wort in a bag kit with 2 packs of Danish Yeast 2042. Yeast was about 2 weeks old.

Made the kit to 20L instead of 23L to make it a bit stronger.

Yeast was cooled to 8 C and pitched into wort at 10 C. SG of 1.056/

Fermented at 10 C.

Day 8 SG was 1.032
Day 11 SG was 1.024
Day 15 SG was 1.018 @ 15C (slowly raised to this temperature over 4 days)
It was racked at Day 15 to a carboy.
Day 16 temperature raised to 18 C with a heat belt. Tasted at this time, no off flavours but slick feel.
Day 21 (today) SG at 1.012 with a less slick feel than before. Still very minor activity in s-type airlock. Still at 18C.

So do I just leave it longer and hope the slick feel goes away? My target SG was 1.012 to 1.014.

I've heard you can pitch krausen to help with the diacetyl. Also wondering if I could just pitch a dry yeast?

 

[Yooper]

I'd try keeping it at diacetyl rest temperatures longer, as long as the beer still seems a bit active that should work.

I've never tried dry yeast to combat diacetyl so I don't know about that.

Edit- I read it again, and saw that the beer was racked before the diacetyl rest was completed. I don't know what to tell you now, as it's yeast the digests diacetyl. For next time, you'll know never to rack the beer until after the diacetyl rest is done, but for this batch I think krausening may be your only alternative.

 

[RiderEh]

The beer is still active even though I racked, there should still be enough yeast to clean it up (I hope). I was getting close two 3 weeks in the primary, hence why I racked it. This was also the time to rack as recommended by john palmers e-book.

The slick feel has reduced in the last 5 days already. I'll leave it another week and taste it again. Also, it is quite carbonated, not sure if that makes any difference in what the yeast is doing?

 

[FuzzeWuzze]

In the future don't transfer it until your going to lager it.

 

[RiderEh]

Why not? I agree you may be losing some yeast from the trub (though most of this should be dormant anyways), but there should still be lots mixed in with the wort if you haven't reached FG.

Should I maybe give this wort a stir? There still is a bit of trub in the bottom since I racked.

 

[RiderEh]

Note I was also following the racking procedure here which says to rack at about 4 gravity points.

http://braukaiser.com/wiki/index.php?title=Fermenting_Lagers#When_to_rack_the_beer

 

[RiderEh]

Just an update, I tasted it this weekend and slick feel persists. I stirred up all of the trub and will give it another week.

 

[Foosier]

I think once the yeast are done there is little you can do to eliminate the slick feel you get from Diacetyl. The only thing I know to do is to prevent it by pitching plenty of yeast and maintaining good temp control.

 

[RiderEh]

What about Krausening? Should I try that or just drink as is.

 

[helibrewer]

There is no harm in trying krausening, just bring it up to room temp.

 

[JimRausch]

General rule of thumb:
If you are going to rack to a secondary, Never, Ever do it until the yeast are finished. After all by racking you are removing the beer from the majority of the yeast. The remaining yeast have to work harder to finish the process, and they may not be up to the task. Why handicap your workers?
I agree with helibrewer. At this point you need to add some active yeast into the picture, and warm her up to keep the yeast active.Should only need it for a couple days if you're just reducing diacetyl. I have not tried krausening before so can't help you with technique, but kai does have a good description. Good luck!

 

[RiderEh]

So I am at 18-19C right now (room temperature). Would it be possible to just add a smack pack at this temperature and hope it cleans it up? Or what about dry yeast?

Lastly, if I Krausen can I use a different yeast? I'm planning on making a Kolsch and was thinking of using some Kolsch wyeast 2565.

 

[JimRausch]

So I am at 18-19C right now (room temperature). Would it be possible to just add a smack pack at this temperature and hope it cleans it up? Or what about dry yeast?

Lastly, if I Krausen can I use a different yeast? I'm planning on making a Kolsch and was thinking of using some Kolsch wyeast 2565.

a smackpack by itself, or a dry yeast pkt probably won't do it as you'll be pitching in an oxygen depleted, higher alcohol environment. But if you take that smackpack, do a starter and pitch that at high krausen stage(12-18 hours) it should stick around long enough to work. This is what people with stuck fermentations usually do.
And yes, you can use any strain of yeast at this point. In fact since you should be pitching warm, it'll be a good idea to pitch an ale yeast. It'll only have to work for a day or 2 before you can cold crash and throw it into hibernation. At this point using a different yeast won't affect your flavor profile(except hopefully removing the diacetyl). But...... before doing that, try warming it up even higher(18 c is 65ish f, right?). If you warm it up to 70-75 f it might stimulate your suspended yeast to eat that diacetyl, and you won't have to be heroic.

 

[RiderEh]

OK I upped the heat with a stronger heat belt to 68F, may wrap a towel around and warm it more when I get home and see if I can get it closer to 75. I'll do another taste test this weekend.

Otherwise I'll make a starter and pitch half in this and the other half in the Kolsch. A little hesitant to do this as I've never made a starter before and don't have a stir plate.

 

[JimRausch]

You don't need a stirplate to make a good starter. Stirplates do help to increase the yeast numbers, but aren't critical. Just keep it warm and give it a swirl every time you walk by.
Let us know how this weekend's taste test turns out.

 

[RiderEh]

Well, the slickness is still there. So a few questions:

Can I make a starter using dry yeast?
How large of a starter should I make?
Do I need a flask or can I just use a 2L Pyrex measuring cup?
Do I pitch the entire liquid that I'm making or do I have to separate the yeast out somehow?
How do I know when to pitch?

 

[NuclearRich]

Can I make a starter using dry yeast?
- You can, but I cant say I've read anyone doing it. You will sure have plenty of yeast this way to combat your diacetyl
How large of a starter should I make?
- For dry yeast, Im sure 1L would be more than plenty. Smack pack might even be ok at 1L, but more is always better, right?
Do I need a flask or can I just use a 2L Pyrex measuring cup?
- You dont need a flask, its just a convenient item that people use. Just make sure you are able to keep that measuring cup covered with sanitized foil
Do I pitch the entire liquid that I'm making or do I have to separate the yeast out somehow?
- You coudl seperate by cold crashing, but that will defeat the 'krausen' part of krausening. You want to pitch it at its most active, and cold crashing will bring the yeast to a halt.
How do I know when to pitch?
- 12-18hrs should do it. You might be able to see an actual krausen, especially with a cell count as high as what dry yeast will afford you.

 

[RiderEh]

Ok thanks! I will do a diaetyl test tonight for fun, and let you know the results and go from there. Hopefully have time to make a starter this weekend.

 

[RiderEh]

Well I did the test. Held at 150F for 25 minutes or so in the oven then let could it be cool to room temperature fairly slowly. I did not detect any hint of butter or caramel scent or flavor. Now I'm really wondering what's up? Could it be Pediococcus?

 

[NuclearRich]

Have you been able to detect diacetyl before with other beer? Some people have much higher thresholds and can't really detect the buttery flavor all that well.

 

[RiderEh]

No I have not, but I had my sister and girlfriend also sample this batch, they noticed the slickness but no buttery/caramel flavours.

 

[RiderEh]

Well I took a sample to the LHBS and they said it has no diacetyl. He said it was a bit bitter, but not infected, and he didn't notice the slick tongue feel like I did. He said if you do notice it, it will be similar to a teaspoon of olive oil, that bad. So he said it's fine and to cold crash it. A lot of worrying over nothing I guess!

 

[freisste]

Were you looking for diacetyl when you first tasted it? Or were you just tasting to see how it was and noticed the slick mouthfeel?

If you were looking for it, it may have been in your head. If you noticed a slick mouthfeel and tried to determine what caused it, it is probably NOT in your head.

Maybe it cleared up in the time between your previous posts and when you got it to the LHBS. Not sure.

 

[RiderEh]

Yes I was looking for diacetyl, but have never tasted diacetyl before. Never noticed butter/caramel flavours only the mouthfeel.

 

[Yooper]

Well I took a sample to the LHBS and they said it has no diacetyl. He said it was a bit bitter, but not infected, and he didn't notice the slick tongue feel like I did. He said if you do notice it, it will be similar to a teaspoon of olive oil, that bad. So he said it's fine and to cold crash it. A lot of worrying over nothing I guess!

Some people genetically can't taste diacetyl, but if he can and you trust him that's a good thing to hear!

The thing is, it's not anywhere near as bad as a teaspoon of olive oil in your mouth! It's more of a "slick" mouthfeel, and sometimes you can feel some oiliness on your tongue or teeth. It's not like a mouthful of oil, but it's definitely got an oily or slick texture to it.

 

[NuclearRich]

The mouthfeel could be related to mash temp. Did your temps drift higher than you expected? More beta amylase from a higher mash temp will give a less fermentable wort, leading to a heavier, slightly sweeter end product.

 

[RiderEh]

No mash, this was a Brew House kit not all grain.

 

[Onthebrew]

Can I pick this up again. I've been trailing the web on this subject. I am new to brewing and jumped it at all grain. I have done both brews, both IPAs, and they both have this slick, oily mouthfeel. My wife can't detect it but I can and it's enough to stop me drinking them.

Problem is I have no idea what causes it so have no idea what to do going foward.

Has anyone got any more to add? Any experiencce and advice would be most appreciated.

 

[RiderEh]

Mine ended up fine, I just diligently check the SG and do a diacetyl rest at 1.023 to 1.024. Done several lagers successfully now.

 

[microbusbrewery]

Problem is I have no idea what causes it so have no idea what to do going foward.

Per the online version or How to Brew:

Diacetyl is most often described as a butter or butterscotch flavor. Smell an unpopped bag of butter flavor microwave popcorn for a good example. It is desired to a degree in many ales, but in some styles (mainly lagers) and circumstances it is unwanted and may even take on rancid overtones. Diacetyl can be the result of the normal fermentation process or the result of a bacterial infection. Diacetyl is produced early in the fermentation cycle by the yeast and is gradually reassimilated towards the end of the fermentation. A brew that experiences a long lag time due to weak yeast or insufficient aeration will produce a lot of diacetyl before the main fermentation begins. In this case there is often more diacetyl than the yeast can consume at the end of fermentation and it can dominate the flavor of the beer.

As far as being "desired in many ales", that's usually at very low levels if at all. In order to avoid it, make sure you have a healthy and appropriately sized pitch of yeast based on the estimated OG, aerate well, and don't rack to secondary before they have time to clean things up. If you suspect a pediococcus infection, you'll get lactic acid plus diacetyl. For that, look at your sanitation practices.

 

[ribsman]

I would agree that racking too early is probably the cause here. The rule of racking to secondary at the 2-3 week point was gospel before we had two week old, super cultured yeast. These days, with super healthy yeast in well aerated wort, you can leave the yeast cake for 4-5 weeks before autolysis becomes a real problem.

Also, what I've been reading is that you can begin raising fermentation temps on lager yeasts after you hit about 40% attenuation without noticeable ester formation. For most healthy fermentations, that's only after 4-5 days. Raise the temp to the upper limits of the yeast for another 4-5 days and fermentation should be close to FG. This is how big breweries are able to crank out lagers in record time. Haven't been able to test this out, but it makes perfect sense.

 

[Onthebrew]

Per the online version or How to Brew:

Diacetyl is most often described as a butter or butterscotch flavor. Smell an unpopped bag of butter flavor microwave popcorn for a good example. It is desired to a degree in many ales, but in some styles (mainly lagers) and circumstances it is unwanted and may even take on rancid overtones. Diacetyl can be the result of the normal fermentation process or the result of a bacterial infection. Diacetyl is produced early in the fermentation cycle by the yeast and is gradually reassimilated towards the end of the fermentation. A brew that experiences a long lag time due to weak yeast or insufficient aeration will produce a lot of diacetyl before the main fermentation begins. In this case there is often more diacetyl than the yeast can consume at the end of fermentation and it can dominate the flavor of the beer.


As far as being "desired in many ales", that's usually at very low levels if at all. In order to avoid it, make sure you have a healthy and appropriately sized pitch of yeast based on the estimated OG, aerate well, and don't rack to secondary before they have time to clean things up. If you suspect a pediococcus infection, you'll get lactic acid plus diacetyl. For that, look at your sanitation practices.

Sorry I should have been more clear, I've read a lot around diacetyl so I know the science behind it but I don't know specifically what in my process is causing it. I was hoping for some advice of those who had been there.

Could be lack of aeriation perhaps?

 

[microbusbrewery]

Sorry I should have been more clear, I've read a lot around diacetyl so I know the science behind it but I don't know specifically what in my process is causing it. I was hoping for some advice of those who had been there.

Could be lack of aeriation perhaps?

Could be. If you're doing anything that's stressing the yeast, that could be contributing. For example, under pitching, under aerating, racking too soon (reducing the number of yeast cells available to clean up residual diacetyl).

 

[RiderEh]

I'm growing large batches of wyeast now before pitching and found this has made the biggest improvement to my beer. Don't under pitch!

 

[xico]

Well, the slickness is still there. So a few questions:

1 Can I make a starter using dry yeast?
2 How large of a starter should I make?
3 Do I need a flask or can I just use a 2L Pyrex measuring cup?
4 Do I pitch the entire liquid that I'm making or do I have to separate the yeast out somehow?
5 How do I know when to pitch?

Edit - Realized I was answering questions to a resurrected thread but the info may well apply to questions above.

1 There will be many that disagree with me, but I think making a starter from dry yeast is a great idea. Yes they were dried with stores of glycogen, but the many hands it changes, the loading docks the pallet sits on in the sun en route to your homebrew shop, many are not going to wake back up. I have some new and old packs in the fridge, I can check the viability of them when classes finish in December and post it.

To make matters worse, Some people follow fermentis' suggestion of dumping yeast right into your wort but a presentation at the World Brewing Congress in August showed dry yeast lose ~30% viability by being hydrated in the high gravity solution due to osmotic pressure. (I will find the source and place it in when I can, PM should I forget) Couple that with serial underpitching many of us do and you have a recipe for inconsistent yeast behavior.

A kreussen formed in a starter lets you know by visual confirmation that some of your culture is at its peak of growth and health..

2- I like ~1million cells pel mL for ales, never kreussened with lagers. I would do what you suggested and build your kolsche for your next batch and pull some off using a calculator or weigh it out at its peak and drop it in.

3- you want some oxygen in your starter to keep the yeast building their reserves and priming themselves for budding. My concern with a measuring cup is the headspace. Molds like oxygen too and may enjoy the sweet damp environment too. The wide mouth is a concern for dust getting in and infecting your starter. I would opt for a steel canteen over that if you have once, preferably something that can be baked. You can bake pyrex with aluminium folded over it for the same result too. Just like the foil enough to pour in your wort and yeast and keep it covered and agitated.

4- I am not in a place where my brew notes are but you can estimate the cellular production from your estimate of how many viable cells you have. I repeat estimate because we are looking for ballparks here. If you have a scale that measures to .1 or better .01g you can tare a small cylinder (I use a 10mL calibrated cylinder (2 bucks at my homebrew shop) mass out your slurry to estimate yeast by weight and volume or just use a calculator and estimate growth.

5-I pitch at high kreussen when keg conditioning and pitch past kreussen for new beers. The high kreussen culture will be most active and ready to absorb the stresses of ethanol and low food environment to scavenge for scraps left over. Past kreussen and yeast begin building energy stores in the form of glycogen that will be utilized from beginning to end of the fermentation. Knowing your organism goes a long way, some yeast don't need an extra pitch to condition and others need help toward the end.