Airlock on a starter

[BigNastyBrew]

I've never done a starter and I'm going to with my next batch. I haven't seen it spelled out but I think the general consensus is "no airlock on a starter." Am I right? Why do you not want one on a starter?

[siwelwerd]

The idea is to promote yeast growth, which requires oxygen. An airlock would prevent additional oxygen from getting in.

[bsegroves]

Hey BNB,

I just recently started doing starters as well.
I think the logic is that the yeast need oxygen and if you just use a piece of foil there can be plenty of gas exchange. An airlock doesn't let any air in.
If you want, check out my two threads that I started a couple of weeks ago here, and the second one here. It might help to see how I progressed before you start.

cheers,
Brannon

[Mylo]

You'll get the most growth with a stirplate, because it will keep the yeast in an aerobic state longer. It drives off the CO2 produced - and you need to allow a way for it to get out, and O2 to get in. Some use foam, but I believe many have more success with a simple piece of sanitized foil.


Mylo

[BigNastyBrew]

thanks for the responses

The starter is my next task. The flasks were just too much for me so I got the glass gallon jugs. I'll stick with the foil. I am just waiting for my stir bar to come in from B3 so I can finish my stir plate.

[ApresSkiBrewer]

also, if the top is properly sanitized... the foil completely covers the top lip. You should still resanitize/flame that lip before pouring from your starter, but the foil will most likely keep that sanitary.

An airlock creates a lip where bacteria/etc. can fall and chill... and then when you pull the stopper... it falls right in the starter and/or you pour it right in your beer.

and obv. +1 on all of the oxygen exchange nonsense everyone else was talking about.