So I just scored a free stir plate, I work for a scientific distributor and one of my colleagues had an old stir plate collecting dust in his storage closet so he gave it to me. So I just made a starter and I have NO idea how fast I should be stirring it... Does it just need gentle agitation, or should it be stirred pretty vigorously so there is a vortex? Also, am I better off using a rubber stopper/airlock combo or just covering it with aluminum foil? Oh yeah, I don't have an Erlenmeyer flask (yet, I have two on order from my company for free as well ) so I'm using a 1/2 gallon glass carboy, hope this doesn't make a difference.