Is my yeast starter infected?

[wfowlks]

So, I have been growing my yeast starter, and I noticed like small little round things floating on top. I was using a stir plate, and the yeast was US-05. The picture was taken as I turned off the plate. Just wanted to make sure it wasn't infected because then I would need to whip up a new batch of the Starsan.

 

[Demus]

Doesn't look like an infection. Dry yeast is designed for use without a starter though. It has to do with how it's made. They do something to it during the dehydration process that makes a starter less beneficial. Maybe someone will chime in with more specifics, but I know I've read that several times from several sources.

 

[stpug]

It almost looks like the yeast beads that come out of the actual package floating on top, but it's hard to tell.

 

[wfowlks]

It was an experiment, as i found a few pellets of the yeast in a corner of the packet once I pitched, and decided to try growing it. Maybe it is the yeast beads.

 

[Shred]

Doesn't look like an infection. Dry yeast is designed for use without a starter though. It has to do with how it's made. They do something to it during the dehydration process that makes a starter less beneficial. Maybe someone will chime in with more specifics, but I know I've read that several times from several sources.

Generally it isn't necessary because dry yeast is cheaper (pitch an extra) and a packet contains more viable cells than a vial of liquid yeast.

I'm not sure the stir plate is beneficial either. Dry yeast doesn't require oxygenation.

As for what the OP is seeing in the starter, I have no idea. It looks like yeast granules.

 

[boydster]

The first round or two of cell divisions don't require oxygen, but if you are starting from just some leftover granules you might do yourself more of a favor by stepping up the starter - the first small one with no need for added oxygen, and any following step-ups with added oxygen. The packets are made to have enough cells and nutrients to grow the yeast colony to the appropriate size for a 5-gallon batch. A few granules is, of course, a much smaller colony and will have greater nutrient requirements. And I agree, it's usually probably not a great idea to make a starter with dry yeast, considering how cheap it is.

I think those are yeast granules in the picture, too.