Yeast Savers - Problem or not?

[allentwnguy]

So I had planned on brewing a 90 shilling ale. I made a 2.5 liter starter (wlp028 Edinburgh ale) planning to save a sample for the next starter. Things came up and I didn't brew. I decided to put up the starter. I boiled mason jars to sterilize. I sprayed with starsan before doing anything, I poured off the top liquid (it was in an Erlenmeyer flask) then swirled until the yeast was in suspension. I filled the mason jar and a smaller mason jar for saving. They went into the fridg. The pint mason jar starter has these raised circles on the bottom. Question has anyone ever seen these before? And is it compromised? The bottom of the smaller jar does not have these.

I just noticed that my Wyeast 1007 German ale save also has these "spots" what gives?

 

[slym2none]

It's likely the last of the flocculating yeast ending up settling on the more dense yeast cake, and maybe some air or CO² coming and making the bubbles.