Hillary Eaton

Originally appeared on Vice

Getting Blazed with a Napa Valley Master Cooper

Aging is one of the most important of the many complicated steps in winemaking. It imparts flavor and influencing tannins to make each wine the unique glass of deliciousness that it is, and that’s classically been a function of the wooden barrels wine is aged in. Simply put, it makes that shit taste incredible.

Barrel making, or coopering, is also one of the oldest and most unchanged aspects of winemaking. While written references to coopering date back thousands of years, the hands-on nature of coopering, the traditional tools, and process of forming a barrel by hand, has changed comparatively little since then, surviving through the a master cooper who hands down the skills and knowledge to an apprentice.

In order to fully understand the ancient art, and the relatively silent heroes of the winemaking world who practice it, I caught up with Douglas Rennie, Master Cooper at Napa Valley’s Seguin Moreau cooperage, to see what he had to say about spending his days making barrels.

heating the barrels for bending- photo credit seguin moreau
A barrel at the Seguin Moreau cooperage. Photo by Seguin Moreau.

MUNCHIES: How did you first get into coopering?
Douglas Rennie: My father is a fourth-generation master cooper, so when I was 16 I went to apprentice at a school for coopers, the same place as my dad and grandfather. I learned how to work in the coopering industry, with all the traditional tools and no machinery, just like they’ve done for hundreds of years now.

What did you do after you finished your apprenticeship?
I worked at the cooperage for Black and White whiskey in Scotland. I was there for 12 years and then I left and found my way to Napa. Seguin Moreau was looking for a master cooper to set up a cooperage in Napa, so they sent me to Cognac, France for a year to work with the head master coopers there, and they showed me all the different techniques in the wine industry. It’s very different—the whiskey industry to the wine industry, the barrel types. It’s night and day difference. There’s so much more to making wine barrels than whiskey. It was a real education I got in Cognac, it was great. The people that taught me were at the top of the game, some of the best coopers in France. Then I came back to Napa to open the cooperage here and now it’s 24 years later.

Douglas Rennie hammering down a hoop onto a barrel- Photo credit Lori Paladino Photography
Douglas Rennie hammers a hoop onto a barrel. Photo by Lori Paladino Photography.

How are whiskey barrels different?
Wood selection and attention to detail. Whiskey barrels go away for four to seven years and are used essentially as a holding vessel. Wine barrels, depending on what style of wine, are away for what could be nine months to two years and are on show in tasting rooms, so they really have to be made like furniture, perfectly detailed and of highest quality. Wine makers really demand high quality, so you can’t get away with taking short cuts. Every barrel must be perfect.

Coopering Tools, Photo Credit Seguin Moreau
The cooper’s tools. Photo by Seguin Moreau.

So what is the typical process of making these barrels?
Wine barrels can’t have any knots or anything in the wood. It has to be straight-grain wood where we bend it so it doesn’t break. It has to be cut perfectly for it. Then we do something called maturation, where we season the wood, and that can take as long as two years. How you season the wood is really important—you don’t just leave it out in the yard for two years. You have to monitor the wood and the weather conditions. They add water to the wood if it needs it, or change all the wood around in winter if it’s too cold. It’s really a detailed process to get the perfect wood for working with the barrel. This is really important because seasoning the barrel leeches all of the harsh tannins out of the wood that would otherwise overpower the wine.

From then, the wood is all jointed and it’s made concave and convex. It’s rounded on the outside and shaved on the inside, which helps the wood bend. Then we assemble every individual barrel, and once they’re assembled we drive the hoops on and start the bending process. We then heat the wood over an oak fire.

Toasting the barrel. Photo by Seguin Moreau.

Why oak?
We can only use oak because if we use gas or pine wood it will impart a different flavor on the inside of the barrel. We put a cable around the bottom of the barrel and it pulls the barrel together at the bottom, forming the shape. Next we lay the barrel on its belly and we put one hoop on the end. Then we release the cable that’s holding the barrel together and from there once it’s bent we toast it. It’s just like how you would toast bread: light, medium, or really dark toast. We use fires to toast the inside, not touching but just heating it, and the natural sugars that are left in the wood when we mature it caramelize, so that the longer the barrel is left on the fire the darker the sugars will become and darken the inside of the barrel. We have to do this slowly because we need the heat to penetrate the wood. The actual toast level should act as a barrier between the wine and raw wood.

Barrels over flame in the cooperage- credit Lori Paladino Photography
Barrels over flame in the cooperage. Photo by Lori Paladino Photography.

Is there any particular trend you are seeing right now in what wine makers are asking for in terms of their barrels?
I think American oak has become a lot more popular now than it was years ago. I think it’s because American oak has evolved so far, also the way we toast the barrels and we season the wood. But every winemaker is so different in what they want.

How much is done by hand on the typical barrel?
We are set up a bit like an assembly line, so we have one guy who will assemble, two guys that bend, and two people that toast, so every four minutes a barrel should move on to the next stage. There’s machinery that will cut the grooves and sand the barrels. With modern machinery we can keep barrels moving through faster. We can make about one barrel in four hours as opposed to the traditional entirely by hand way, where you would make about one barrel per day.

heating a barrel for bending, photo credit seguin morea
Heating a barrel for bending. Photo by Seguin Moreau.

Does that mean old-fashioned coopering is on its way out?
I’ve been hearing that it was a dying trade since I started in coopering, but it’s still here and I think the wine industry is really keeping it alive. The more people become educated about wine and the more they want to drink good wine the more there is a need for good barrels, so that does help keep an old trade like coopering alive. But for sure it’s a dying trade.

Got it. Keep the flame alive, Douglas.