Yeasty flavor in recent batches

[JonM]

Hey, all.

Three recent AG batches have all wound up with a strange yeasty flavor that I can't figure out.

What's really odd is two of the yeasty batches are a recipe I've made plenty of times before (variations on a SMASH). The first couple of batches with that recipe all came out with a nice clean flavor and were perfectly clear in the glass. The most recent two of that same recipe are very cloudy and have a pronounced yeasty flavor.

The clear batches and the yeasty ones were made with the same process, same mash schedule, same yeast (1056). The later two with the yeasty flavor both finished at 1.010. One of those later two was bottle conditioned for a month and chilled in the fridge for 8 days and still had the yeasty flavor.

Here are the only changes in the process from the clean batches to the yeasty batches: the yeasty ones were bottle conditioned at slightly higher temps (70s and 80s rather than 60s) and the yeasty batches were made with a shot of pure 02, while the clean batches were aerated with shaking alone.

Any thoughts? I'd really appreciate any input. Thanks!

 

[Reno_eNVy]

Here are the only changes in the process from the clean batches to the yeasty batches: the yeasty ones were bottle conditioned at slightly higher temps (70s and 80s rather than 60s) and the yeasty batches were made with a shot of pure 02, while the clean batches were aerated with shaking alone.

Any thoughts? I'd really appreciate any input. Thanks!

The bolded statement... that's it, 100% positive. Higher temperatures will cause the yeast to throw off esters and phenols, one of which is what you're probably experiencing.

Keep those temps in the 60's but if you can't keep them constant/... that's pretty dang important to keep clean flavors.

 

[JonM]

Hmm - they don't have a estery taste, it's definitely yeasty. And they're cloudy while earlier batches are clear.

 

[rollinred]

This is interesting because I nearly quit brewing because of this flavor. My solution ended up being switching to dry yeast. Not one batch since has had that flavor.

But since your using pure oxygen this is not likely your issue.

Do you cold crash for a few days? There is a good chance that because of the oxygen your yeast numbers are drastically higher and may take longer to fall out of suspension. A couple days cold crash might help.

 

[JonM]

I didn't cold crash the fermenter. I have the bottles in the fridge and plan on leaving them for a couple weeks (well, as many bottles as I can reasonably fit in the fridge.) Maybe that'll do the trick.

Next time around, I'll try the cold crash and maybe some finings in addition to the Irish moss I use in the boil.

 

[jtejedor]

Sometimes Chico yeast is a little stubborn to drop out of suspension. At least in my experience. I really don't think the higher temperature would affect the beer since not much fermenting is going on in the bottles.