slick off flavor.

So lately all of my beers have the same slight off flavor. I can't quite put my finger on it, but they all finish a little slick and almost overly bready. I've made sure that I pay close attention to my sanitation and i have a temp controlled chest freezer for fermentation. Anyone ever experienced this?


my two theories are that:

1. I am under pitching. Out of my last 3 batches, 2 of them I pitched US-05 straight in the fermentor, the other I made a starter that was on the small side.

2. Something in my chest freezer in contaminating them. The bottom of my chest freezer is constantly getting slightly moldy (little dark green dots)

Thanks all.

"Slick" is a sign of diacetyl most often, but pedio infection can cause that too I believe.

One thing that may help is warming the fermenter a bit at the tail end of primary fermentation. So, if you're fermenting at 65 for 5 days, maybe at the very end of fermentation go ahead and raise it to 70 to finish up and "clean up" diacetyl.

Stressed yeast produces diacetyl, but there are some strains of yeast that produce more diacetyl than others also. S05 usually doesn't produce much diacetyl, though, so infection is another thing to consider.

That makes a lot of sense. My fermentation temps have been on the low side. when do you do a diacetyl rest?

sgraham602 said:

That makes a lot of sense. My fermentation temps have been on the low side. when do you do a diacetyl rest?

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When fermentation slows down, at about day 5 or so.

Yooper said:

When fermentation slows down, at about day 5 or so.

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Day 5 is fine in most cases, but, to the OP, as you get familiar with different yeasts, OG levels, duration of lag phase, etc. you'll have a better idea of when to raise the temp. I do a D rest with virtually every batch, as it also encourages the yeast to finish attenuating and clean up. I find with WLP002 a D rest as the krausen drops works, but with WLP001 the krausen likes to stick around longer so usually take a reading before allowing temp to rise.

is there a "sweet spot" of when to let it rise? I'm tempted to do a slow rise with my heater in my chest freezer, taking it slowly from 65 up to 70/71 over the course of 5 days. Is it worth it? or would it be more advantageous to just ferment at a higher temp...say 72 deg.

Yooper said:

When fermentation slows down, at about day 5 or so.

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does this still apply if i plan on doing a 3 or 4 week primary? Would i raise the temp up a hold it for the rest of fermentation or just for a few days.

After 75% of the fermentation is done temperature really doesn't matter anymore unless you drop it and put the yeast to sleep too soon.

With my setup I let the fermentation go until the kraussen drops and then I take the temp probe off the side of the carboy and raise the temp in the fermentation chamber by at least 5 degrees. This raises the chamber temp but lets the beer in the carboy raise gradually. Give it at least 2 or 3 days at the higher temp and then do whatever you want. Leave it at the higher temp for as long as you want or move it to cold crash if you are in a big hurry.

I've been using this process with all yeasts since I got a keg full of diacetyl using S04 yeast. No more greasy microwave popcorn flavored beer for me.