I don’t know if I mentioned this anywhere before, but when I was in school I found the Enoferm alpha ML to be full of Pediococcus. I found it by accident, but it cleared up a mystery. We had an Oenococcus antibody that we were using for research, and when we used the Enoferm alpha, we were having problems detecting the Oenococcus with the antibody. My little accidental discovery cleared up that mystery. None of the wines we used it on ever had any problems, though. No high VA’s or anything.
Serious question here…could a dope sniffing dog be trained to find this stuff?
Serious question here…could a dope sniffing dog be trained to find this stuff?
Perhaps…maybe definitely empty barrels that are infected? You could train a dog, maybe to smell a bunch of wine samples and let you know which ones smell like they have some Brett…then again, this is largely what we already do. Perhaps an early detection system?
A few folks have taught their dogs to sniff TCA as part of cork QC, but I would imagine their pups’ efforts are backed up with traditional analysis and are as much for a fun story as anything.
Retrievers have also been trained to find vine mealybugs.
There was a company at Unified (Vinquiry I think) who has a new test kit for Brett detection sensorially. The chemical in the kit is added to a wine sample, and if 4EG/4EP is present at below threshold levels, it intensifies the aromas. I don’t see it in their current hand catalogue, and I don’t have time to look online to see if it is there.
We use Vinquiry for all analysis, esp. Brett detection. And the Ozonator is a rock-star addition to the winery. We clean everything with it!
I think the company mentioned in the article had a booth at Unified, and I think there was at least one other company with a booth on pcr techniques for detecting critters in your wine.
-Al
Welcome to the board, Al! ![[cheers.gif]](/uploads/db3686/original/2X/0/0ff9bfcdb0964982cd3240b6159868fbdf215b1a.gif "cheers"){kind=small}
I saw this brett detection gizmo in the new Wine Business Monthly:
http://www.partec.com/preview/cms/front_content.php?changelang=6&parent=&subid=&idcat=315
It won a commendation in the 2008 Vinitech Innovation Awards. Not a lot of info on the web page as to exactly what it does or how it works. WBM states that it “screens for and enumerates contaminants from Brettanomyces.” Anyone heard of this device / have comments on it?
As you said, not much info, but it looks like a small flow cytometer, which I used a lot in my research. It was originally developed for medicine and the examination/enumeration of blood cells, but it can be used for both yeast and bacteria by use of antibodies specific for the organism and some sort of fluorescent tag.
Here is some info;
Flow cytometry - Wikipedia" onclick="window.open(this.href);return false;
The good thing about flow is that you can fairly quickly enumerate your yeast (or whatever), and you can also differentiate live/dead.
It’s my impression that one of the big challenges with brett detection (the yeast, not the byproducts) is sensitivity because brett can be present in very low concentrations but dormant, escape detection in the relatively small samples analyzed, and then bloom at a later time when conditions have changed. Brett yeast cells tend to not be active at low temperatures (seems to require temps of 55 or lower to really control), they are stunned but not killed by free SO2 and can wake up when the SO2 drops as the wine ages (particularly a problem if temperature variations cycle air/oxygen past the cork), and they require nutrients like fermentable sugars and nitrogen from fermentation aids and I don’t know what else.
But it’s also my impression that viable brett yeast cells make it into many or maybe most oak-aged red wines, so maybe brett is as much about limiting the potential level through assiduous cleanliness and controlling the post-fermentation nutrients as it is about detecting small levels of brett prior to bottling.
One of the brett detection methods claims a threshold of 1000 cells per ml. They argue that this is a virtue of their method because it reduces false positive rates. But it seems like an awful lot of cells ready to leap into action if conditions become right.
Sooo, this seems like an area of winemaking with plenty of pitfalls.
-Al
Most of the literature, and my profs as well, claimed that brett was a very fastidious yeast, but I never had any problems growing it up. We had a collection of 31 strains when I was in school, and before I got there they hadn’t had a microbiologist as a student/grad student in quite a while, so my first summer there I spent culturing/sub-culturing our entire yeast collection, which hadn’t been done in over 2 years. You are supposed to culture plates about every 6 weeks. Anyway, there was only one brett strain in the collection which i could not get to grow up again. I did some limited research on their micronutrient requirements but never really saw any evidence of the fastidiousness that was written about. Maybe because it was not in a wine matrix, but rather on media? IDK.
I had also heard of some unpublished study of Brett strains with some very high SO2 resistance. I never saw if the research was published or not, though.
Yes, 1x10^3 cells/mL? You have a problem.