Foam over from starter

I'm doing a 2 liter starter (wlp001) in a standard growler. Took off and foamed over which I was expecting since I didn't have much headspace and had the growler in a bowl to contain the overflow. What I didn't expect was that the foam ended up looking sludgy like a yeast cake rather than just foamy wort. Do yeast get suspended in the foam? Would that loss effect my end cell count in the starter much? Probably had about 50mls flow over so it wasn't too substantial.

Yes that foam likely has healthy yeast in it. I wouldn't sweat it. I would be thinking about a bigger vessel or a second growler if you want to make another starter of that size