Monday, December 6, 2010

A beginner's guide to wine bacteria

No, not written by me you'll be glad to hear but by a 'microbial enologist' called Erika Szymanski in the online wine magazine Palate Press. And who has done such a good job of it that even a layman like me can follow it (just).

Well worth reading - although I can't resist one small dig - which is about the yeast and bacteria manufacturing company Lallemand referring to their product ProMalic® as 'naturally' lowering juice acidity. You can read more about their product range here and here. (I was particularly fascinated by the products Booster Rouge and OptiRed.)


  1. Fiona: Schizosaccharomyces pombe is known as a very interesting tool to study cell biology, due to its unique fission characteristics. It was first obtained from local beers is Swahili-speaking African tribes (hence its name). I’m not sure it is a natural part ot grape environment; as a matter of fact, I think it isn’t. As such, I agree with you the word “natural” is not applicable.
    But I have two more concerns: (i) when used indiscriminantly, it provokes off-odours and (ii) it allows formation of alcohol rather than lactic acid, in the course of malic acid degradation. It will then change the chemical composition of the wine and its aromatic profile in a way totally different from “classical” malo-lactic fermentation or, for that matter, (semi-)carbonic maceration.

  2. What I find educational about Erika's article is that Kloeckera is the main "wild" yeast present on grape skins. This could be an explanation for why not adding "industrial" yeast makes a difference in the finished wine.

    Again I'd love a winery to make two otherwise identical cuvees (obviously bottled separately) - one fermented with wild yeast and the other "industrial". This must have happened.

  3. I guess it must Graham although I imagine many small winemakers couldn't afford - or want to conduct - 'experiments' like this. I agree it would be fascinating though.

  4. That sounds like an interesting experiment, and I'd do it myself next year if I had the resources! I don't think a packet of 'industrial' yeast should be too expensive, but how to sterilize the must and/or kill off the natural yeast in it?

  5. Good point, Fabio. I'll leave that to the winemakers to answer!