yeast starter autolysis

[Mark]

Hi all,

I've recently made a yeast starter with a stir plate, the first one I've made. I left it spinning for possibly too long (maybe 36 hours), and it's developed a rubbery smell, what I imagine autolysis to smell like. It doesn't taste like infection, but it doesn't smell great. Yeast was healthy and active, the starter was built up from a stationary starter which had no problems at all. Is the yeast ok to use? Has anyone else had this problem? How long should a starter spin for?

Cheers
Mark

[warra48]

You will not have autolysis after a mere 36 hours.

What you've done is to oxidise your starter beer, hence the rubbery smell. This is not uncommon with starters made with a stir plate, simply because the starter is constantly exposed to oxygen, and because the Co2 produced is also constantly displaced from the starter wort.

The yeast itself should be fine. Chill the starter, and just pour off all your starter beer, and use only the slurry.

[Mark]

thanks warra, that's a relief i don't have to chuck my yeast!