Brett -- teaching an old goat new tricks

I just returned from judging at the CA State Fair and the judges seminar this year was on Brettanomyces. We were given a "clean" base wine, along with several samples of the base wine innoculated with different species of Brett, of which there were three examples of each (innoculated three months apart).

I always thought Brett was Brett. I did not know there were so many species, all with differnet aromas and flavors -- some were pleasant; some were not.

I'm not a microbiologist by any stretch, so I'm wondering if why I prefer some Rhone houses over others is because their winery is populated by a particular strain of Brett that is pleasing to my taste buds, whereas another house is colonized by an unpleasant strain. I'm just thinking out loud here.

Any thoughts, ideas, experiences?

Hi Randy,
The only thing you have to remember, when it comes to yeast and bacteria, as Jack Keller states there’s the Good, Bad, and the Ugly. The Bad and the Ugly can be tagging along for the ride. I guess commercial wineries, through sterile filtration and then inoculating with a “desired” organism, and making the environment and conditions ideal for that organism’s survival, and with careful observation (microscopic identification); can be almost certain that a “desired” organism is doing the job it is intended to do. In places like France, where they have been making wines for thousands of years can a certain species of an organism be dominant? Certainly. With what scientist know today they are isolating different strains of yeast and bacteria in New World vineyards. This is why amateur winemakers like me have a vast number of strains to choose from.

Salute

Any thoughts, ideas, experiences?

Why not? Proving it scientifically might be a challenge because of the number of variables to account for, but what you're saying is reasonable on the surface.

Bucko-

For my own tastes I thought it was the volume of the Brett that mattered. You now, a little bit can add some interest and complexity, but if it dominates everything else, then not so enjoyable.

So there are different strains that cause various different aromas? Interesting. How would you describe the different smells? Were there others besides "barnyard" and "band-aide"?

Were there others besides "barnyard" and "band-aide"?

Absolutely, which fascinated me. One strain smelled and tasted like rose petals, another of new leather, another of a funky/earthy quality that was pleasant, and two others that had the nasty band-aide/metallic qualities.

The latter was unpleasant even at lower titers, while the former was not bad even at higher titers. It was an eye-opener for me, because I do not get to play around in the lab/winery ferreting out such things.

Were there others besides "barnyard" and "band-aide"?

Absolutely, which fascinated me. One strain smelled and tasted like rose petals, another of new leather, another of a funky/earthy quality that was pleasant, and two others that had the nasty band-aide/metallic qualities.

The latter was unpleasant even at lower titers, while the former was not bad even at higher titers. It was an eye-opener for me, because I do not get to play around in the lab/winery ferreting out such things.

Maybe there's a little Weber-Fechner going on here. Whereas the threshhold and the increments for the "bad" Brett may be low and hence easily discernible, those for the "pleasing" Brett may be higher and not necessarily so obvious to a broader public. In other words, it's simply easier to taste the bad stuff as opposed to the good stuff and so the good stuff gets glossed over .

In other words, it's simply easier to taste the bad stuff as opposed to the good stuff and so the good stuff gets glossed over .

That, or you gravitate to one wine over another because of the more pleasing qualities for your palate that you may not be able to lay a finger on.

I'm not a microbiologist by any stretch, so I'm wondering if why I prefer some Rhone houses over others is because their winery is populated by a particular strain of Brett that is pleasing to my taste buds, whereas another house is colonized by an unpleasant strain. I'm just thinking out loud here.

Any thoughts, ideas, experiences?

That's likely the case. Glad you finally found out about one of those competition award-winning components! It's one of the tricks of the trade.

Bucko-

For my own tastes I thought it was the volume of the Brett that mattered. You now, a little bit can add some interest and complexity, but if it dominates everything else, then not so enjoyable.

So there are different strains that cause various different aromas? Interesting. How would you describe the different smells? Were there others besides "barnyard" and "band-aide"?

Marc,

The aromas have also to do with the interaction between malolactic fermentation and Brett--spontaneous malolactic as opposed to induced; strain of inoculant when ml is induced, etc.

A lot of the aromas are produced by biogenic amines that are created during or after ml.

Randy, If you ever hear of a seminar like this being offered in the Puget Sound area, please let me know. This sounds very much like something I would like to attend. -- Clark

Randy, If you ever hear of a seminar like this being offered in the Puget Sound area, please let me know. This sounds very much like something I would like to attend. -- Clark

Clark, this is a little beyond the Puget Sound area, but a year and a half ago I attended an interesting one-day course on wine faults at Cental Washington University in Ellensburg. It's taught periodically by Amy Mumma, mostly for ITB types (although I'm not ITB). Covers basic stuff like VA, oxidation, sulfur dioxide, cork taint, sulfides, mousy taint, and of course brettanomyces.

Not a great deal of time was spent on brett and my chemistry background is limited to a year's snooze in high school but according to Mumma there are nine different brett species, the two most common being B. intermidius and B. lambicus. She says the volatile phenols specific to Brett include 4-ethyl-phenol, the band-aid aroma, sometimes associated with barnyard and sweaty saddles; 4-ethyl guaiacol, the smoky, spicy, burnt, wet wood aroma; and and then there's 4-vinyl guaiacol and 4-vinyl phenol isovaleric acid, a rancid horse-like aroma. Can't say I remembered (or understand) all this but, unlike my high school days, I took notes.

If you are interested in finding out if the course is coming any time soon you can call the Central Washington University Office of Continuing Education at 800-720-4503 or 509-963-1504.

I remember on the old WLDG having a discussion on Laube's 67 score of the Havens Bourriquot, a wine that I (moderately low on bretty sensitivity, and fairly tolerant when I do sense) didn't find at all bretty. A poster named Mike Christensen said he hadn't had that wine, but most Havens reds he found undrinkable. He said he didn't mind moderate amounts of brett, but felt there was something about that strain that he found DNPIM.
Sensitivity seems to vary widely, and further it seems some strains bother some people more thanothers.

Sensitivity seems to vary widely

While we all know that TCA have have a thousand-fold variation in taster's perception, I have not been able to find stats on Brett. I would assume it varies as well, but I'd only be guessing as to the levels.

Sensitivity seems to vary widely

While we all know that TCA have have a thousand-fold variation in taster's perception, I have not been able to find stats on Brett. I would assume it varies as well, but I'd only be guessing as to the levels.

According to Mumma's notes, if I read them corectly, Brett sensitivity varies by type of volatile phenols: "ethyl phenols are a fault above 400 microgram/litre and vinyl phenols are faults at levels above 700 microgram/litre," she says. But some Brett by-products have identification levels of only a few cells per litre, and aromas sometimes vary according to concentration. For instance, high concentrations of tetrahydropyridines produce a mousy aroma but low concentrations produce a popcorn or bread-like aroma. But then tetrahydropyridines can also be made by lactic bacteria, not just Brett, so it isn't always easy to identify the culprit as Brett.

It is easy to see that this is a very complex subject, not just a wave of the hand followed by, "Brett!" I'm not inspired enough to delve into the microbiological aspects in depth, but I do find the subject fascinating. Thanks for the additional data.

If you are interested in finding out if the course is coming any time soon you can call the Central Washington University Office of Continuing Education at 800-720-4503 or 509-963-1504.

Thanks, Clint. Ellensburg is not that far away. I'll try to check this out.

-- Clark

A most interesting thread.

Another, related topic these days is velcorin. For those unfamiliar with the product, reproduced below is the Scott Labratory FAQ:

VELCORIN

Q: How does Velcorin work?
Velcorin inactivates microorganisms by entering the cell and inactivating some of the key enzymes required for cell function. The current thought is that Velcorin causes methoxycarbonylation of histidyl residues in the enzymes alcoholdehydrogenase and glyceraldehydes-3-phosphate-dehydrogenase. Excess Velcorin then completely hydrolyzes in the presence of water.

Q: What factors determine Velcorin effectiveness?
The effectiveness of Velcorin depends on microbial type, microbial load, pH and other factors. At low doses Velcorin is very effective against yeast and fermentative bacteria. At greater doses Velcorin is also effective against bacteria and certain fungi. The effectiveness of Velcorin also depends on the initial microbial count. Pretreatment of wine must reduce the microbial load to less than 500 microorganisms/mL. Velcorin is not a replacement for good sanitation practices.

Q: How long does Velcorin remain active?
Velcorin activity is based on its hydrolysis rate. Hydrolysis occurs when Velcorin reacts with water to form methanol and carbon dioxide. The rate of this reaction is dependent on the temperature of the wine. At 10°C (50°F) it takes approximately 4 hours for Velcorin to completely break down. At 21°C (70°F) break down occurs in about 2 hours.

Q: Do I have to list Velcorin as an ingredient on the label?
No. The FDA lists Velcorin as a direct secondary food additive and therefore no labeling is required (21 CFR 101.100).

Q: What are the hazards associated with Velcorin?
Velcorin in its pure form is moderately toxic by ingestion, highly toxic by inhalation, irritating to the skin and eyes and combustible if exposed to an open flame. Due to these hazards, people are required to wear safety gear when handling Velcorin and are given regular safety training.

Q: Why do I have to use an approved dosing system?
Due to the unique physical properties of Velcorin and to help assure safe handling, Lanxess requires the use of an approved dosing machine. Velcorin is only 3% soluble in water and solidifies at 17°C (63°F). The dosing machine is designed specifically for Velcorin, complete with adequate safety features, a special metering system and temperature controls to prevent Velcorin solidification.
Q: Are there mobile service providers available for dosing Velcorin?
Yes, there are five mobile Velcorin service providers. See the Velcorin section for the contact information.

Q: How much Velcorin can I use in my wine?
The TTB allows up to 200 ppm of Velcorin in wine, dealcoholized wine and low-alcohol wine (27 CFR 24.246).

Q: What type of packaging is compatible with Velcorin?
Velcorin can be used with nearly all packaging options such as plastics (PET, PVC), cans, glass, bag-in-a-box and others.

Q: What is the cost associated with adding Velcorin?
Velcorin costs $387.38 per 3 kg bottle. The first price break occurs at purchases over one ton. One bottle of Velcorin will dose 15,000 liters at 200 ppm. This corresponds to a Velcorin cost of 23.3 cents per case (about 2 cents per bottle) when dosed at the legal maximum (200 ppm).

http://www.scottlaboratories.com/info-c ... tation.asp


Now if I understand this (and please correct me if I don't) this stuff will kill Brett, among other bacteria, assuming the populations aren't beyond limits. Then, in a relatively short period of time, it breaks down into CO2 and methanol. I assume that the CO2 is either dissolved in the wine or is discharged upon opening the bottle but I have not been able to find out what happens to the methanol and whether or not it could be considered harmful to humans (and what dose may be considered harmful)(and if it accumulates in human tissue).

And I mention this because I know this product is now being used on the leftcoast during bottling.
We may have beaten back the Brett but at what cost?
Best, Jim

Jim,

The last seminar I attended on this subject left me with the impression that the level of methanol produced was in contention and that many winemakers were uncomfortable with that, especially since wineries will soon have to list ingredients on labels. It won't look good to list methanol

There was a mention in the stuff you posted about pH. The growth of Brett and biogenic amines is highly reliant on pH levels, as is ml fermentation, and so the strength or weakness of certain aromas and of certain levels of bacteria or yeast infections fluctuate based on the wines stability, of which pH is a leading indicator.

In the pH range of 3.0-3.3 things are quite manageable. Higher than 3.3 swings into risk territory. (Below 3.0, forget ml. )

The last seminar I attended on this subject left me with the impression that the level of methanol produced was in contention and that many winemakers were uncomfortable with that, especially since wineries will soon have to list ingredients on labels. It won't look good to list methanol

I find it somewhat amazing that it isn't required already.
Can you answer any of my questions about the effects of methanol on humans - specifically if there are any, are they harmful, at what doses and are they cummulative?
Best, Jim

Methanol poisonings causes significant morbidity in the United States annually, and even relatively small ingestions of this alcohol can produce significant toxicity.

The "parent alcohol" (methanol) is relatively nontoxic, and causes mainly central nervous system sedation. However, when this parent alcohol is oxidized (primarily by alcohol dehydrogenase) profound toxicity ensues.

Formate causes retinal injury with optic disc hyperemia, edema, and eventually permanent blindness, as well as ischemic or hemorrhagic injury to the basal ganglia. These changes are postulated to result from disruption of mitochondrial function. Complaints of visual blurring, central scotomata, and blindness suggest methanol poisoning.

Keep in mind that the general population is routinely exposed to low levels from metabolic processes and from such dietary sources as fruits, vegetables, fruit juices, and foods and soft-drinks containing the synthetic sweetener aspartame.

Serious toxicity has been reported following ingestions of as little as 8 g of methanol. Although data on the health effects of chronic exposure are limited, one report cites evidence of visual disturbances observed in workers exposed to high concentrations of methanol vapors. The report found no evidence of carcinogenic, genotoxic, reproductive, or developmental effects in humans attributed to methanol exposure.

I believe the words "wood alcohol" describe the havoc that methanol can create. Am I right Randy?

Yup.

Indulge me my ignorance a moment - I assume Brett is a species of yeast?

Brettanomyces is a non-spore forming genus of yeast in the family Saccharomycetaceae, and is often colloquially referred to as "Brett". The genus name Dekkera is used interchangeably with Brettanomyces, as it describes the teleomorph or spore forming form of the yeast.