Airlock vs foil

[jeff0001]

I'm making my yeast starter tonight and in the last I have always used a stopper with an airlock. Recently I have heard about using foil instead. What is the purpose of this and is there any real difference?

 

[Fishin-Jay]

You're trying to multiply your yeast which means the yeast need oxygen. So you should be using foil to allow a two-way exchange of air, or a foam stopper. Your airlock will prevent air from getting into your starter and will limit the yeast's ability to reproduce.

 

[helibrewer]

I'm making my yeast starter tonight and in the last I have always used a stopper with an airlock. Recently I have heard about using foil instead. What is the purpose of this and is there any real difference?

It is suppose to help with O2 exchange, but very little O2 is actually going to diffuse into the fermenting starter given that copious amounts of CO2 are coming out.

What you really want is to keep your yeast in suspension with a stir plate and oxygenate by infusing 100% O2 into the starter when you pitch.

If you are doing the "shake once in awhile" method there won't be any difference between using an airlock or foil.

 

[bigbeergeek]

Sanitized foil also keeps the rim of the flask sanitized until you pitch. I like the simplicity of spraying a square of foil with starsan an and calling it done.

 

[manisfive]

I plan on doing a my first starter tomorrow depending what my smack pack looks like. I have a flask and a foam stopper. I'm kind of nervous about the stopper keeping out nasties but it has to work as well as foil I guess.

 

[StMarcos]

It is suppose to help with O2 exchange, but very little O2 is actually going to diffuse into the fermenting starter given that copious amounts of CO2 are coming out.

What you really want is to keep your yeast in suspension with a stir plate and oxygenate by infusing 100% O2 into the starter when you pitch.

If you are doing the "shake once in awhile" method there won't be any difference between using an airlock or foil.

Yup, this would be my take as well.