Author Topic: Pellicle identification  (Read 1331 times)

Offline unclebrazzie

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Pellicle identification
« on: February 03, 2015, 09:29:22 AM »
I was wondering...is there a way to visually determine pellicle identity besides applying a microscope?

There seem to be several common visual types of pellicle going around, rangin from a flat surface skin, to more alien white balloony bubbles, all the way to colourful ridges. Are they all the same organism(s) or does each mibrobe and strain have its own pellicular characteristics?
Any literature available on pellicles?
Michael Tonsmeire mentions in his American Sour Beers  how several commercial sour beer brewers visually inspect the pellicles on the ageing beers in their barrels. Maybe we're only just in the stage of pragmatic empirical practice, rather than hard-boiled science...
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Offline kramerog

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Re: Pellicle identification
« Reply #1 on: February 03, 2015, 03:20:10 PM »
The difference between a flat pellicle and the white balloony bubbles are only bubbles.  If there is no off-gassing then bubbles do not form in the pellicle and the pellicle stays flat.  I have not observed colorful ridges.  I have not seen differences in pellicle between lacto and Brett. My 2 cents.

Offline reverseapachemaster

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Re: Pellicle identification
« Reply #2 on: February 03, 2015, 04:10:47 PM »
The only things you can identify with any accuracy by looking at the pellicle is how well it is covering the top of the beer and whether there is any mold growth on it (which is extremely rare).
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Offline Jimmy K

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Re: Pellicle identification
« Reply #3 on: February 03, 2015, 07:59:36 PM »
Well, you could inoculate an agar plate and use the colony growth pattern to ID it. That's not really easier though.
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Offline unclebrazzie

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Re: Pellicle identification
« Reply #4 on: February 04, 2015, 08:39:48 AM »
I agree that identification of microbes can only properly be done by means of a microscope. And/or plating techniques.

My reasoning was that since different plated microbes produces visibly different plaques, perhaps there's a difference in pellicle morphology as well.

Anyone have any experience with Brett-only pellicles vs Lacto-only vs Pedio-only?
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Offline reverseapachemaster

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Re: Pellicle identification
« Reply #5 on: February 04, 2015, 04:17:09 PM »
I agree that identification of microbes can only properly be done by means of a microscope. And/or plating techniques.

My reasoning was that since different plated microbes produces visibly different plaques, perhaps there's a difference in pellicle morphology as well.

Anyone have any experience with Brett-only pellicles vs Lacto-only vs Pedio-only?

I've done several brett-only beers and their pellicles look identical to pellicles in beer with both brett and lactic acid bacteria.

I'm not entirely sure what causes different thickness or opaqueness in pellicles but I suspect a major contributing factor is the extent of oxygen exposure as the primary purpose of a pellicle is regulating exposure of the beer to air (and competing species that might fall into the food source).
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Offline unclebrazzie

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Re: Pellicle identification
« Reply #6 on: February 04, 2015, 09:26:38 PM »
Does anyone know of any academic studies on pellicle-forming micro-organisms?
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