First Time Using Stir Plate

Just made a standard Thursday night 2L starter for a Sunday brew, but put on a stir plate for the first time.

I usually decant off and pitch the slurry if the starter has reached that point by brew time. But what should i be looking for with the stir plate...keep it spinning and in suspension until time to pitch and pitch it all?

How am I proving viability if it all stays suspended, or will it start to settle in a bit even while on the stir plate?

It will stay suspended as long as it's on the plate, but you will see CO2 bubbles rising as an indication of fermentation with white bubbles collecting on the surface and in the vortex made by the stir bar spinning or sometimes you will see a krausen on the surface, but krausen does not always happen with starters. Regardless, the presence of rising CO2 and the formation of foam shows the existence of fermentation which gives you viability.

I usually spin it for 48 hours, then refrigerate overnight. This is where you see the new white cells that reproduced. Then decant at brew time and allow the slurry to warm.

cool.. so spin till sat night, refrigerate, and the rest of my life is normal again.

thanks.

Yep, should work great for you. Happy brewing.

I usually spin it for 48 hours, then refrigerate overnight. This is where you see the new white cells that reproduced. Then decant at brew time and allow the slurry to warm.[/QUOTE]

+1 except I pitch cold. Montanaandy

Here's a guy at Wyeast talking about starters. To answer your specific question, 18-24 hours, according to this guy.

18-24 hours is good. If you want to save a smidge in you mash or boil, don't decant and use that towards your wort. 2L into a 23L batch really isn't much to affect anything.

Thanks for all the replies guys. Solid on the starters. Just never used a stir plate.

Happy brewing all!