Checking Infection in a Starter

Wed Mar 26, 2008 6:42 pm

I'm about a quarter of the way through reading New Brewing Lager Beer (Noonan). In the yeast chapter, culturing section, referring to creating starters off of slants, he says that "in professional practice, a swab of yeast from the starter is cultured on a slide and microscopically examined for contamination before the parent culture is pitched".

But, I've heard from other sources that the percentage of bacteria which could ruin a starter is small enough that searching one slide is absolutely no guarantee of a clean pitch.

Does anyone out there know if there is a procedure for which the slide method works? The way Noonan refers to culturing on the slide makes me wonder if there is a way to beef up the cell count on the medium.

I'm certainly not a microbiologist, so I'd also love to know how feasible this would be to do at home.
SternBrew
 
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Wed Mar 26, 2008 6:48 pm

Pour a bit of it into a glass and taste and smell it. That's how I do it, if it is a multi step-up starter.


Mylo
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