Chitosan

Has anyone played around with any of these products? I was intrigued enough by the Enartis version (StabMicro) to attend a workshop at Vinquiry a couple weeks ago. What caught my eye about this one was that the website seemed to indicate, vaguely, that its efficacy wasn’t limited to brett. At the workshop, the Vinquiry research enologist said that she was finding that StabMicro was effective against cells of all sorts – bacteria as well as yeast – though the research was not far enough along to reach a definitive and publishable conclusion yet. She was less far along in testing against gram-negative bacteria (acetobacter) and was more tentative on that front than on the pedio and lactobacillus end. She has found the only organoleptic effect to be a diminution of 4EG/4EP associated with brett at standard 10g/hL dosage. Too good to be true?
I don’t fight much brett, but I have battled pedio, and the lysozyme cure costs a fair bit of color in pinot. It would be great if chitosan turns out to be a silver bullet that replaces lysozyme, extra SO2, filtration, etc. I just did a bench trial on a couple lots of pinot at 10g/hL, and I couldn’t find any organoleptic difference between treated and control bottles. So far, so good. Anybody else further down the road with any of these products?

Don’t know much about Chitosan in the winery. Worth noting though that is has some very interesting effects as a vineyard spray.

As it is pretty interesting to me, I’ll read into it and report back anything of note.

Here’s a digital dropbox of recent peer reviewed journal entries on the topic.

Stewart - With the form of Chitosan that you use do you add it to the wine and and the rack the wine off or is it something you just add it ala so2? Ive heard of the “No Brett Inside” product that requires racking so I imagine that’s the approach with all of them, but Im curious what your experience is.

Some of the No Brett Inside literature reads like it’s more of a fining agent that just drags down yeast so that you can rack off. The is a link on the Scott labs site to a study of more extended aging with chitosan and occasional lees stirring that suggests that it has ongoing ability to kill brett.
I attended a microbe management seminar at Vinquiry where their researcher said that their chitosan product, StabMicro, was showing the ability to kill a broad range of microbes beyond just brett. My experience with StabMicro has been that it has no organoleptic effect at 10g/hL. I’ve treated in barrel and have stirred a couple times. I don’t have great before/after Scorpions comparisons, but I think it knocked out a small pedio population and knocked back acetobacter pretty significantly. If it really is effective against pedio and lactobacillus, it’s a pretty attractive alternative to lysozyme. One interesting thing is that the only things that have shown up on a couple Scorpions panels, besides some lowered acetobacter counts, was viable saccharomyces and oenococcus. I suppose that’s a mixed bag, but it might make me think about using it early on – like with a stuck ferment.

Thanks Stewart. Very surprised to hear bout the Oenococcus. I assumed this was something you had to do after MLF.