Monday, January 6, 2020

Result of a 10-year experiment: does filtering out brett work?

This blog post has been 10 years in the making.

A decade ago, I interviewed Cameron Hughes. He's a San Francisco-based wine negociant and I've interviewed him a bunch of times, but on that occasion, he said something -- and gave me a bottle -- that I wanted to test.

Hughes had bought a batch of 2008 Napa Cabernet that he said was full of brett, so much that the producer couldn't risk releasing it under its own name. He boasted that he sterile-filtered out all the brett and now he had a prestigious wine to sell.

What if you didn't get it all, I asked. Even a little brett in the bottle could increase over time.

Hughes told me if I checked the bottle in 10 years, I would find no brett. And he gave me a bottle.

Which I put away for a decade.

Last week I got it out of my cellar. And on Saturday night I opened it. What would I find?


This is the part where I talk about how the world was different in 2010, when I put this bottle away.

The first iPad was sold in 2010. A DVD-by-mail company named Netflix introduced streaming video.

In 2010, California still had more Merlot and Zinfandel planted than Pinot Noir. Oregon still had almost no outside investment in wine. Moscato was just about to take off with consumers.

Steph Curry in 2010
When I had this conversation with Hughes, the San Francisco Giants had never won the World Series. Even though the Golden State Warriors were terrible, they sold for $450 million in 2010. The Warriors had a skinny rookie guard who could make some outside shots and they had the No. 6 pick in the 2010 draft, which they spent on Ekpe Udoh. LeBron James made The Decision and left Cleveland without a title. Lamar Jackson was in middle school.

Three newspapers that I had worked for full-time still existed: the Tampa Tribune, Hayward Daily Review and San Mateo County Times.

And California winemakers almost universally hated brett, which is short for "brettanomyces."

Quick explanation. The sugar in grapes is converted into alcohol by yeast, thus carrying out God's plan by turning grapes into wine. This happens naturally if you leave grapes in a bucket.

But there are many kinds of yeast. Most wine is made by yeast from the genus saccharomyces. But yeast from the genus brettanomyces naturally occurs in vineyards and can also convert sugar into alcohol. However, it gives a range of aromas and flavors that includes many nasty ones. It's possible to get some nice aromas from brett -- in fact, a UC Davis brett seminar I attended in 2012 was one of my most mind-expanding wine experiences of the decade.

But in 2010, I still thought what UC Davis still taught -- that brett was a "spoilage organism." Some French winemakers embraced it. But California winemakers (with the notable exception of Chris Howell at Cain Vineyard & Winery) thought it was the devil.

That's why a Stags Leap winery would sell its expensive wine cheaply to Hughes: brett could not be tolerated.


Today I wonder how that wine might have tasted unfiltered. Maybe it would have had brett-based aromas like coffee, cola and graphite. Or maybe it would have had brett-based aromas like horse or smoked meat. Who knows?

I just wanted to see if the sterile filtering worked. So I opened the bottle and let two glasses of it sit out at room temperature for hours.

Cameron Hughes
At the end of the evening -- nope, no brett. Not even a trace. The wine was fruit-forward, full-bodied, seamless: your basic Napa Cabernet. I confess I found it boring, but this is the style that has made Napa famous. Anyone who bought Hughes' Lot 189 a decade ago would have been happy with it.


A lot of winemakers are probably smiling indulgently at my naivete right now. Dozens -- hundreds -- thousands of wines from California and elsewhere are sterile-filtered every year. Of course it works, you're thinking. Why would a wine journalist be surprised at that?

I've been writing about wine for a while, and this is the only opportunity I've had to test a sterile-filtered bottle like this, where the proprietor admitted it was full of brett. I'm sure I drink older wines all the time that had been sterile-filtered. But nobody -- NOBODY -- tells the wine journalist, "This was full of brett, but we took it all out." One thing I've always admired about Hughes: he tells it like it is.

So now I know that it works! See, it wasn't a wasted decade after all.

You can't buy this wine anymore (sorry), but I was surprised at the random older Cameron Hughes bottles I could find on Wine Searcher, all pretty cheaply. Check it out.

Follow me on Twitter: @wblakegray and Instagram @wblakegray and like The Gray Report on Facebook.


Austin Beeman said...

Well that's Science for you. Testing something that is believed to be true, but not proven. Thanks for doing this.

Michael Beltran said...

Excellnt post on the wine and Cameron Hughes. One must remember all of the older California wines that were fermented and aged in redwood tanks. Many of those wines remained very drinkable with lots of years on them. Tasting like a varietal not always. So there must have beeen brett in those wines and it did not take away from the pleasure of drinking them.

Jack Everitt said...

Putting the wine in a plaster ziplock bag is fairly effective too.

tercero wines said...

It does not sound like you tried the same wine 10 years back - that would have been an interesting comparison. And it would have been even more interesting to try the wine that Cameron purchased before 'removing' the brett in it.

Something to point out here, though, is that sterile filtration will not remove the 'effects' of brett that may already be in the wine - it will only remove live cells and the ability for the brett to bloom and 'get worse' over time

Also, I believe 'micro filtration' did exist back then, and this could have been used to selectively 'filter out' undesired 'brett aromas'. i certainly know it exists today.

I agree that brett is a controversial topic among winemakers, not only in the US but in other parts of the world as well. And I also agree that all of the aromas associated with brett are not very well understood. When I was at UC Davis, I took part in a sensory study in which the same wine was inoculate with a number of different strains of brett and it was allowed to bloom. We then smelled each wine blind in a sensory lab setting - and the results were fascinating. The aromas ranged from molasses and brown sugar to campfire smoke to horse poop, and there was even one sample that literally made my physically ill just smelling it - it contained putricide from the brett.

Fascinating stuff indeed . . .


Larry Schaffer
tercero wines

Steve said...

Be careful of a possible confusion: Brett itself has no smell, it is a living organism (yeast) that produces ethyl-phenols. The odor comes from the ethyl-phenols, and can vary from spices, cloves, band-aid, pharmaceutical to leather, game meat and horse manure. Filtration can indeed remove Brett, but it won't remove ethyl-phenols if they are present. The wine will still smell bad 10, 15, 25 years down the road. To be efficient, the filtration needs to happen BEFORE Brett produces significant ethyl-phenols. Otherwise, you can remove ethyl-phenols, but with a different technique than filtration...