What the heck is going on with this batch?

[DVCNick]

What I do is make a starter of about 1800ml, pour off a little as the seed for next time, and then pitch the remaining ~1500. So if the yeast was contaminated somewhere along the line, it could explain how both batches got that way.

I'll let this one ride and see if a full pellicile develops.
The last one I kegged and let carb most of the way and could tell something was off about the taste. I'm pretty convinced it wasn't right.

Took that keg all the way apart. Took the fermenter all the way apart before this batch and made sure every surface I could access was sparkling clean, and any I couldn't had a long hot soak in PBW.

 

[DVCNick]

Actually I do have a picture of it at high krausen... Forgot I took that one.

 

[Vale71]

What system do you use to brew? Is it BIAB, 3 vessel, RIMS...?

 

[DVCNick]

Three vessel with a cooler mashtun.

 

[ESBrewer]

If you have reused the same (old) yeast preparation in these two batches as I understood, I would say that the yeast culture is the most likely source of an infection. The risk that a minor infection in the culture will escalate during the following fermentations is always big. Based on the pictures the bubbles seem to be somewhat sticky so it could be infected or not, hard for me to say. But if it did not taste good last time it is probably some sort of infection.

 

[Vale71]

Three vessel with a cooler mashtun.

Do you get clear wort into the boil kettle and do you separate trub or do you dump everything in the fermenter?
The reason I ask is that abnormally large bubbles are usually caused by excessive particulate matter in the wort, such as malt flour and hop material. This can act as nucleation sites causing abnormally large bubbles to form and rise to the surface. If that's the case than this won't really affect fermentation excpet for its external appearance.

 

[DVCNick]

I actually run the wort through fine mesh hop spider between the mashtun and kettle, so all grain chunks are removed. "Flour" would still probably get through though.

I try to leave as much trub as possible in the boil kettle... but I'm sure a little bit makes in it. I whirlpool the kettle then let it settle for about a half hour, then transfer until I just start to see some trub moving, then stop.

 

[DVCNick]

Current status... Thoughts?

 

[DVCNick]

This is my hope... next time I'll probably do a very similar recipe with new yeast, everything else the same, and see what happens.

If you have reused the same (old) yeast preparation in these two batches as I understood, I would say that the yeast culture is the most likely source of an infection. The risk that a minor infection in the culture will escalate during the following fermentations is always big. Based on the pictures the bubbles seem to be somewhat sticky so it could be infected or not, hard for me to say. But if it did not taste good last time it is probably some sort of infection.

 

[RPh_Guy]

Current status... Thoughts?

It's not a pellicle.

 

[DVCNick]

Thanks... I know the pictures are not perfect but I don't see a uniform white haze on the surface. Just the big sticky bubbles. It is easier to see on this batch because it isn't dry hopped yet.

I guess I'll proceed with dry hopping and kegging. The smell is not so great right now either. Not horrible, just not great.
If I have that same waxy aftertaste again I'll let it sit for a couple weeks and see if age changes it. If not, not sure if I'll power through or dump it.

Next batch will of course have a new batch of yeast. The old one is already chucked out.

 

[DVCNick]

Just an update... kegged that most recent batch and let it sit for two weeks and tried it. Still doesn't taste "great", but, it's a simple smash with some on-sale pale ale malt; I wasn't expecting any sort of championship winning result anyway. Definitely not bad enough to be a dumper though. I might have been a bit hasty in dumping that first one.

Next batch I did was ten gallon batch (first time at that) with a recipe I've done a number of times. Used new yeast pack, different fermenters, new boil kettle for the first time (so definitely nothing in the ball valve although I feel that was basically eliminated as a source anyway). Only thing I did "questionable" was use a 1-gallon glass jug for the starter since I needed a bigger one. It was an apple cider container that I repurposed. It had a good long soak in PBW and I even submerged the neck in boiling water for about 15 minutes since it has some threading on the outside. Couldn't detect any residual smell. Seemed clean as I could get it.

But... big bubbles in the starter, at times looked like the pictures above. Pitched it anyway since it's what I had. Now I've got the thick dark krausen like the most recent "high krausen" picture above. I'm sure once it falls I'll see the same big bubbles on the surface.

Everything was changed and the yeast starter vessel is the only questionable thing I can think of. Not sure whether I'm crazy or what. I'm just used to seeing a tight white krausen with these recipies and yeast, and I'm not getting that anymore.
We'll see how this 10gal batch turns out; I know how it is supposed to taste.

 

[DVCNick]

Current look.

 

[RPh_Guy]

Looks normal to me.