Yeasty Off-Flavors

[twgardner2]

My last two batches have come out with a flavor that I can only describe as "yeasty". I was previously describing it as "horse blanket" but I'm not sure I know what that actually tastes like. I've settled on "yeasty".

I believe it is due to high fermentation temperatures. Both batches used liquid yeast (WLP001) and a 2L starter. I've never had any issues with sanitation and this doesn't taste like an infection to me. It isn't medicinal or solvent-like. It just tastes like the yeast-cake smells. The first batch is really yeasty. I'm not even going to drink it. The second one is less yeasty and, I think, drinkable. I don't have my fermentation temp under control and I know it is the most important thing I need to work on right now. I want to get a fridge and johnson controller, but I just haven't found a fridge for the right price yet.

The first batch had no temp control whatsoever. It sat in "the brewery" in the basement at around 80-85 degrees. I haven't been doing secondaries so the beer sat on the cake for 25 days. Based on the first batch, I knew I needed to implement some form of temp control for the next batch, so I did the ice bath method, maintain temps between 62 at 70 during active fermentation. After active fermentation died down, I let the temp rise to ambient temp (again, 80-85). This beer sat on the cake for 28 days.

I was very surprised to taste the yeasty-ness in the second batch. I'm starting to think it is due to long(ish)-term primaries at elevated temps, and that controlling temp during active fermentation only reduced, vice eliminating, the off-flavor.

Until I do find my fermentation fridge, do you think I'd be ok if I continue with the ice bath cooling during active fermentation, then racking to secondary with out the ice bath? Luckily, temperatures are coming back down as fall approaches so it might not matter again until next summer.

 

[Boodlemania]

Ice bath is definitely better than letting set in 80F temperatures. Other suggestions I might add:

1. Do the "wet T-shirt and fan" method to aid the ice bath in controlling temps.
2. Forget the secondary. Just leave on the cake. 1 month isn't going to hurt anything.

 

[funkenhop]

Glad to hear Fall is coming to the rescue. I also have no fermentation temp control other than the trusty ice bath in the summer and a non-auto-shutoff electric blanket in the winter.

You're very right to be doing the ice bath as necessary, especially with WLP001 which isn't particularly pleasant at higher temps. Considering your room peaked at 85 degrees, it's very likely that your actual fermentation temp crossed into the nineties, a bad place to be flavor-wise for most strains.

I would not recommend primary for four weeks in those kinds of high temps, even if you keep the temps lower in the initial days of fermentation as you did on your second batch. I routinely run primary for four or even five weeks, but I would not do so at the temps you mention. The bulk of the yeast will die too rapidly and begin to autolyze.

Speaking of autolysis, is the strong yeastly flavor you are tasting accompanied by a rubbery smell or taste? That of course means get off the cake sooner with elevated temperatures. Keep your summer primaries shorter than your winter. Rack to secondary after the first week or bottle at three, depending on your gravity.

 

[Clementine]

Ideally 62-65 for WLP001 it will be so clean it will blow you away. Only let it raise up to 70ish at the end to help clean the beer up.

Hoewever I'm guess your active duty military stationed in Naples and so PCSing means you are trying to avoid accumlating too much stuff to ship home. For a quick fix try a swamp cooler (google will give you a million hits) basically its a tee shirt over your carboy and fan blowing on it. The tee shirt wicks up water and the fan evaoporates it cooling your brew. Even if you can get your brew down to 70s you will really notice a flavor difference. If it is really hot you can bottle condition the same way with a bucket with beer bottles in it half covered in water and with a towel/tee shirt covering them and the fan blowing on it.

Clem

 

[twgardner2]

Thanks for the feedback everyone!

Speaking of autolysis, is the strong yeastly flavor you are tasting accompanied by a rubbery smell or taste?

No, no rubbery smell/taste, it just tastes like opening a vial of White Labs and taking a swig. Friends who I've had try it say I'm exaggerating. Maybe I am more sensitive to the taste or maybe I'm just really hard on my beer (the latter is probably more likely)

I would not recommend primary for four weeks in those kinds of high temps, even if you keep the temps lower in the initial days of fermentation as you did on your second batch

You're right, I will definitely not be doing extended primaries unless I have temp control down.

Hoewever I'm guess your active duty military stationed in Naples and so PCSing means you are trying to avoid accumlating too much stuff to ship home.

I am active duty Navy stationed in Naples, however, it isn't a matter of accumulating stuff (I'll take all the brewing stuff I can get!), it is more about finding a 120V fridge. I am in goverment housing and have dual-voltage (both 220V and 120V), which is amazing, but I have yet to find the right deal on a 120V used fridge. Hopefully I'll find a good deal before it gets hot again.

Thanks everyone!