starter/stir plate question

from what I've read about starters I'm under the impression to put an air-lock on the flask to keep the nasties out. the directions on my stir plate say NOT to put an air-lock on the flask, the yeast needs to be in contact with the air to reproduce. doesn't really go into any detail beyond that. this will be my first starter and first time using a stir plate so I'm a bit confused here. please advise - thanks ahead

The directions you received are correct - do not put an airlock on your starter. What the directions may not have said is that you should cover the flask loosely with sanitized aluminum foil. The foil allows for fresh air to constantly exchange with the wort on the stir plate, but keeps critters from floating down into your starter. No "bugs" have the ability to crawl up your flask, under the foil, and into the wort. Except for actual bugs, of coarse, but that is unlikely.

Joe

Yep, no airlock, you want oxygen transfer, but cover with sanitized foil as jfowler1 suggests. Have fun with your first starter and the new stir plate! I don't know why, but I love watching a starter spinning away on a stir plate. I guess it just gets me anticipating that next brew.

as always fellas, much appreciated

Those little foam stoppers are pretty niffty too. Pretty cheap piece of mind for me. Think they're less than $1 apiece & I get a few uses out of them.

I think a part of what a stirplate does is to keep the yeast in suspension so that the wort and yeast are in constant contact, air exchange does happen but it is not the primary function of the stirplate, at least that is what I have come to understand!

See http://maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices for judging the effectiveness of a stir plate, and why you shouldn't use an airlock.

FWIW, I don't use sanitized foil. (We never use it for anything else.)

Instead, I use a sanitized jam jar inverted over the flask. It allows for an exchange of air, and prevents anything from dropping into the starter, plus it's reusable.

-a.

I usually put the airlock on but don't fill it with liquid. I'll maybe put a little bit of vodka in the bottom to try to trap flies that manage to find their way in.

wow some really good ideas and feedback here. much thanks
any other tips for someone whos never used a starter or stirplate before? doing a 10g. batch on sunday, do I need to get on this tommorro?

You should get on it tonight so you can put it in the fridge on Saturday evening. That way you can pour off some of the starter beer and pitch mostly yeast with a minimal amount of oxidized/stale beer. Either way I wouldn't worry too much about it.

I have a kolesch yeast in my starter... It is the first time on a stir plate. I keep having issues with the starter over foaming, popping the top and dumping yeast out. Why am I getting so much foam. It is a 1.040 starter, one liter of wort in a two liter flask.

BrewMoreBeers said:

I have a kolesch yeast in my starter... It is the first time on a stir plate. I keep having issues with the starter over foaming, popping the top and dumping yeast out. Why am I getting so much foam. It is a 1.040 starter, one liter of wort in a two liter flask.

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Is it Wyeast 2565? I've found that yeast seems to go a bit bonkers. My last starter with that strain kept doing the same thing.

Foil sprayed with star san is the way to go, IMO. Doesn't get cheaper than that if you normally have it in the house.

does the speed setting on the stirplate contribute to the over foaming at all?

no over foam if it is off the stir plate. but, it if is on the plate is goes crazy from about hour 3 thru hour 10

BrewMoreBeers said:

no over foam if it is off the stir plate. but, it if is on the plate is goes crazy from about hour 3 thru hour 10

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