I occasionally get e-mails (and forum posts) asking questions about identifying yeast versus bacteria in microscopy images. I’m just posting this here as an example of what an average yeast looks like compared to an average bacteria.
At the top of the image is a cluster of a normal yeast strain – Wyeast 1007 (German ale). They are slightly out-of-focus as I was trying to get the bacteria into focus. At the bottom of the cluster are two budding yeasts, in the middle is another budding yeast which is budding upwards (hence why the small bud is in-focus) and there is a non-budding yeast in the upper-left corner of the cluster. The “strand” extending upwards is a clump of trub.
The bacteria is an ‘average’ bacteria (E. coli, which you hopefully will never see in your beer), but which I added to this sample as a comparator.