Off flavor - sat on yeast too long?

[opalko]

Sorry if this isn't the best forum for this, but one batch was extract the other allgrain, so I didn't know where to post....

The last 2 brews I made (one all grain, one extract) have had a semi-strong off flavor after I keg/bottle. Both were simple American pale ales, using fresh ingredients (I don't have the recipes handy but the OG were right on target at around 1042 and FG around 1008-1010). I used Safale S05 yeast in both cases (new yeast).

The off flavor has a strong yeast bite to it - at least that is what it seems like to me. Not sure I would classify it as "butterscotch" or "vegetable" as other off-flavors I have read about. My wife says it just tastes very hoppy to her.

The only thing I might attribute it to is that the beer spent 2 weeks in primary before being chilled down and then racked before kegging/bottling (I was out of kegs for the extract batch and had to bottle). But I almost never do secondary fermentations for simple ales anymore, though I wouldn't think 2 weeks was too long?

Any ideas?
Cheers -
Robert

 

[makomachine]

Not too long and frankly a minimum time on the cake that I allow. You could leave it on much longer without issue and if anything it allows for the yeast to cleanup the beer, not the other way around. How long has it been carbed and what temp did you ferment at?

 

[marcycaulkins]

Not long enough. I do a minimum 3 weeks in the primary, but i'm lazy, so usually more like 6.

 

[opalko]

Fermented at 65F in my spare frig w/controller. The keg has been carbed for about a month, and the bottles only about a week. I've made plenty of other batches the past few months and sampled after about the same time without having this flavor occurring. I thought the first time was a fluke, but then the same thing in the second batch has me wondering.

 

[opalko]

I don't see how it's not long enough. I check the gravity over 3 consecutive days and when it doesn't dip anymore I consider it ready.

 

[makomachine]

I've never used S-05, but seems that's the new element in your brewing. I'm thinking it's tied to that strain, but will let someone who uses it regularly respond. I would think your fermentation temp was good.

 

[Yooper]

I don't see how it's not long enough. I check the gravity over 3 consecutive days and when it doesn't dip anymore I consider it ready.

Yeah, two weeks or so is plenty long enough. I like to leave the beer in the fermenter for about a week after fermentation is over, more or less.

 

[opalko]

When I said "new yeast" I should have said "fresh yeast". I've used it many times before with success (it's the dry yeast version of 1056 by the way).

 

[jdlev]

Yeast will clean up any diacetyl if you leave them in their long enough in late/after primary fermentation (commonly referred to as the 'diacetyl rest'). Did you make a starter? It sounds like you had the right temp for the fermentation, but maybe your pitch rate was off a bit?

 

[marcycaulkins]

Just because the fermentation is done doesn't mean the yeast are done. I do a long primary because the extra time gives the yeast a chance to clear the beer, clean up off flavors, and lets the yeast cake compact so that you can get a cleaner siphon. Sorry I can't be of more help as far as identifying the off flavor, but I would definitely say it is NOT from sitting on the yeast cake.

 

[opalko]

When using dry yeast I don't make a starter.

Yeast will clean up any diacetyl if you leave them in their long enough in late/after primary fermentation (commonly referred to as the 'diacetyl rest'). Did you make a starter? It sounds like you had the right temp for the fermentation, but maybe your pitch rate was off a bit?

 

[unionrdr]

It may not have been done yet.It sounds like it also had the temp go up at some point. At the very least,it didn't get time to finish,& clean up it's by-products. Try to age it longer too. It'll clean up some that way.
I've had beers take a 3rd week to finish & get rid of that green bite sort of flavor. If you're getting vegetable-like flavors,that's another problem.
Take a look at this;http://www.howtobrew.com/section4/chapter21-2.html

 

[jdlev]

Also, what types of cleaners did you use. You could get chlorophenols if you have any residual cleaning solutions in your setup (from chlorine or bleach).

 

[jdlev]

When using dry yeast I don't make a starter.

How big was the batch?

 

[JetSmooth]

I don't think two weeks is too long at all. Most of my beers sit for three weeks minumum and I don't secondary.

What were your ambient fermentation temperatures? Edit: your response was afer I posted. I agree with what's been said, it doesn't sound like the yeast had time to clean up.

 

[McGarnigle]

I don't think two weeks is too long at all. Most of my beers sit for three weeks minumum and I don't secondary.

What were your ambient fermentation temperatures?

I think this is, without question, the most likely culprit.

 

[opalko]

I think I used Iodophor for the first and bleach for the second, as I ran out of Iodophor. 5 gallon batches.

For those saying a longer fermentation is necessary - are you saying you leave the fermentation go 3 or 4 weeks in the primary, or do you rack over to a secondary vessel at some point? And - even for a simple ale??

Edit: I see you're leaving it in primary for much longer periods than I am used to. I'll try a longer fermentation next time.

 

[Tinga]

what temp was the wort when you pitched your yeast?

 

[opalko]

Normally I pitch when the wort is around 72F

 

[unionrdr]

I don't use a secondary at all,unless I'm adding something I don't want reacting with the yeast cake. I let all of them sit at least 1 week after FG is reached to clean up & settle out more. It's the 1st step of conditioning,as many of us now view it. And yes,even simple ales. All beers should be given the time to clean up & settle out more.
Look at the link I posted in post #12.

 

[makomachine]

Bleach is a bad choice of cleaner/sanitizer as well. Invest in some starsan and never look back IMO. I'd also pitch cooler as well - 65-68 for an ale.

 

[Tinga]

Normally I pitch when the wort is around 72F

well no problem there....

 

[McGarnigle]

Actually, if the room is always around 72, that's a little high. Inside the pail, things are a bit warmer. This would cause off flavors.

I personally think the argument for leaving it in primary longer is overstated. It won't hurt, and your beer might be clearer, but your yeast probably was done even with its conditioning phase after 2 weeks for a small-ish beer.

 

[Irrenarzt]

Sounds like a combination of issues are going on here. Bleach is a major no-no. You can bleach but be sure to star san after rinsing the hell out of the bleached containers. I only bleach if I have some dead hooker scent in my containers but you need to rinse it with an ungodly amount of water then star san it as well. I would say not enough time on the yeast as well as a temperature fluctuation in the up direction could be your main culprits. Without tasting for myself, it's hard to say but I would say no more bleach, invest in a chest freezer with a digital temperature controller and a thermowell stopper for more even ferment temps and do a 3 to 4 week primary, no secondary.

Did you dry hop? I notice dry hopping can impart a vegetal flavor if done over 68F and for too long.

 

[opalko]

Odd, most of these things I've done for years without this occurring before. The 72 was measured in the wort, not the room. I'll forego bleach from now on (though it doesn't explain the iodophor sanitised batch), and use starsan instead. I'll give the next batch a bit more time in primary.

I'm hoping the flavor will mellow out given a little bit more time. Cheers!

 

[jdlev]

Actually, if the room is always around 72, that's a little high. Inside the pail, things are a bit warmer. This would cause off flavors.

I personally think the argument for leaving it in primary longer is overstated. It won't hurt, and your beer might be clearer, but your yeast probably was done even with its conditioning phase after 2 weeks for a small-ish beer.

Trudat...remember that even though your ambient temp reads 72, your actual fermentation temp could be as much as 5 degrees hotter. I try to ferment my ales no hotter than 65. Sticking them in a tub of cold water and adding ice every so often is a great way to stay right around 65 for me.

 

[Irrenarzt]

Time will probably help. It usually does.

On Big Brew 2011, my assistant pitched rehydrated S-05 in 100F wort as a cooling line to the chiller broke and he freaked out as the yeast was at 30 minutes while I went for a pizza. Initial tasting results were unfavorable but we left the batch on the yeast for 30 days, then racked to keg and let condition at 35F for another month on gas. I just tasted the first pint last night and somehow it is now fairly decent. I'm still giving the batch to him but the moral of the story is that time can help you out more often than not.

Also, get better temp control. You'll thank me later. It's amazing what 1 degree F delta can do for your beer. Worth every penny.

 

[dcp27]

I personally think the argument for leaving it in primary longer is overstated. It won't hurt, and your beer might be clearer, but your yeast probably was done even with its conditioning phase after 2 weeks for a small-ish beer.

+1, 2 weeks was plenty long with this.

 

[unionrdr]

I disagree. I've had beers finally reach FG at 3 weeks,& still cleaned up a tad more at that point. But it does seem to start "cleaning up" when it gets close to FG. But the clean up can happen later than two weeks. but I wouldn't say much later either,ime.

 

[dcp27]

true it can take longer, but in a beer of this size/type, if you haven't reach fg within a week, you probably did something wrong.

 

[unionrdr]

That's not true 100% of the time. Most ales take more than one short week to be cleaned up & settled enough to bottle. I've never had one go that fast.

 

[NordeastBrewer77]

I agree, union. True, many ales reach FG in a week or so but the beer is almost always better off on the yeast cake for an extra week. Personally, if I reached FG in a week (I never check SG before two weeks), I'd still leave it in primary for a minimum of three weeks. No harm, only benefit there. It's the old brewin' n quein' thing. Slow n steady wins the race.

 

[dcp27]

sorry i didnt word that right. I didnt mean that I'd bottle this after 1 week, just that it'd reach its fg within a week. and I kinda left out the part where I'd leave it for another week afterwards to clean up. you can wait longer if you want, but IME the extra time for a small beer yields pretty minimal benefits, so I'd rather be able to start drinking it sooner, YMMV.

 

[unionrdr]

Imo,as long as it's cleared to a slight haze & tastes good (for a green beer),then go ahead & bottle.