Commercial Bottle Yeast Harvest

[Gerald Godwin]

Hey Everyone,

I just attempted my first yeast harvest from commercial beers on my brew last weekend. My homebrew club is having a brew-off where we all use the same porter recipe, and everyone selects their own yeast. I made two separate starters; one from an Old Slug porter and one from a Fuller's. By the time is stepped them both up to 2L, I had a decent sized yeast cake in the bottom of both starters. I decanted both starters into 4 gallons one week ago today.

After 48 hours, I didn't notice really notice any activity in either of the carboys. I checked both of their gravities at that time, and they both read 1.051, 4 points below the 1.055 from brew day. Two days later, the Fuller's had a pretty good looking krausen on top of it, while the Old Slug had something covering the top that didn't look like any krausen I had ever seen. I let them both continue on until today, when I checked the gravity of just the Old Slug which was still at 1.051. I pitched a random dry yeast packet that I had sitting at home, and two hours later a krausen had already formed on top.

I guess my question is, do you think this will turn out ok? The carboy looked like this before I pitched the dry yeast packet.

And here it is after pitching the dry yeast today.

Is that the looks of an infection floating on top? I've never waited so long between brewing a beer and getting good yeast in the wort, so I'm wondering if it's too late for this one. I know I'll find out in a couple weeks when I go to keg this, but I'm just curious what everyone thinks.

Thanks

Jerry

 

[IslandLizard]

Although it does look a bit gnarly, it doesn't look like a pellicle, as they tend to be covering with a haze before becoming denser.

Not sure why the Old Slug didn't take off like the other one, although it did eat 4 points off the top. Maybe a slow fermenter?

 

[Comfort_Zone]

Doesn't look like an infection to me, looks like protein chunks.

 

[Gerald Godwin]

Thanks for the replies. I’m excited to see how it turns out. Makes me feel a little better that it doesn’t seem like an infection.

I ended up checking the gravity of the Fuller’s beer the next day, and even with a krausen it had hardly fermented either. Only down to the high 1.040s. I probably should have taken a reading the next day to check for a change, but I also ended up just adding dry yeast to that one as well.

And in my initial post I said I had a decent yeast cake to pitch in them. I just cold crashed a starter of White Labs Saison I yesterday, and it’s pretty clear to me now that the porter yeast cakes were nothing compared to this. I’m starting to think that I just massively underpitched these beers.