If you’d rather sip a California Chardonnay than a French Chablis, most likely what delights you is the influence of oak, since both wines are made from the same grape but are produced differently.

Conversely, if you disdain wines that remind you of caramel, coffee, or vanilla, most likely what you object to can be chalked up to the use of oak in the production process.

That’s because many of what we think of as “wine” flavors come not from the fruit itself but from the vessels in which it is fermented and aged. Unbeknownst to many consumers, oak is the man behind the curtain.

Marcus Rafanelli is an instructional technician at Walla Walla Community College’s Center for Enology and Viticulture and the cellar master at its College Cellars. He is also the 2019 recipient of the Bill Powers Sabbatical Fund scholarship, which gives up to $5,000 to someone currently working in the Washington state grape or wine industry who is under 40 and has five years of experience in viticulture or enology.

Rafanelli chose to use his award to spend three weeks in France, traveling from Bordeaux to Burgundy via the Loire, studying the life span of the wine barrel from acorn to cellar.

“I wanted to become the oak expert here at the school, so I wanted to learn about barrel production from beginning to end,” he says.

“I studied plant biology in college, and I’ve always been interested in how things grow,” Rafanelli continues. “Now that I’m in my 13th year of winemaking, I wanted to learn more about how oak influences the wine we make, about the different oak compounds, and how the different coopers build their barrels. And I wanted to learn more about the nuances of each of the cooperages we work with here at College Cellars: Seguin Moreau, Demptos, Saury, Sylvain, Leroi, Sirugue, and Tremeaux.”

After learning that he had been awarded the scholarship, he set out on an eight-month planning spree. Doing everything he could to make $5,000 stretch as far as possible, he scoured the internet for airline deals, eventually waiting for a Black Friday sale to secure his tickets. He scouted out inexpensive car rentals and hotels and contacted dozens of people in France’s artisanal barrel-making industry, setting up a daily itinerary of visiting cooperages and the old-growth forests that supply them.

In preparation for meeting with coopers, he also read everything he could get his hands on, including “Barrel Making, An Art in the Service of Wine” by Jacques Puisai. There he found this delightful quote that helped him think about barrel making in a whole new way: “Our vessels for wine, whether large or small, do not like to be inactive … a barrel is happy when it is full. When a barrel is empty, it is sad.”

Although most of us will never give a moment’s thought to how to keep a barrel happy, winemakers think about barrels all the time.

“Once upon a time, we used barrels as a shipping device, because they were much more robust than clay pots. It turns out that they taste good too,” says Tim Donahue, director of winemaking at Walla Walla Community College.

Sabrina Lueck, the college’s enology instructor, adds that she thinks of oak as the spice cabinet of the cellar.

Rafanelli explains that a new barrel imparts flavor compounds to the wine and also allows for micro-oxygenation of the wine, helping it to develop from juice into elixir. Older barrels that have already been used still allow for micro-oxygenation, but no longer impart oak flavors to the wine.

Rafanelli shares what he learned when visiting the Bertranges forest in the Loire, which was first planted in 1121.

“They’ve been managing these forests for barrel production for hundreds of years,” he says. “Each tree begins with an acorn falling naturally to the ground.”

Growing barrels is a long game. The trees are selectively thinned once or twice in the first 50-year period of the forest’s life, to favor the straightest, tallest trees. The forest is thinned again every 25-30 years, and then cutting typically begins when the trees are 120-150 years old.

Once cut, the wood embarks on the several-years process of becoming a barrel. The wood must be dried, split into stave lengths, seasoned, bent into shape, and toasted, almost all of which is done by hand.

Rafanelli describes what he saw: “Each of the coopers I visited had their own toasting style and their own way of seasoning the wood. I think that’s the most important thing — where they season their wood and for how long.”

The staves are seasoned outside for two to five years. While they are out in the weather, they are subject to the growth of trichoderma mold, which helps to break down the surface of the wood and leach out the harsh, bitter tannins from the oak.

As a result of this trip, Rafanelli says, “I will be able to help our students pick their oak better, now that I’ve seen how different barrels are made. We pay $1,000 a barrel for new French oak, which seems expensive. But when you consider that each barrel can be traced back to its original tree, and that tree started growing at least 120 years ago, and all the time and effort and different steps that go into making a barrel, $1,000 seems like a really good deal.”

And to Rafanelli’s surprise, he learned that Walla Walla wine wasn’t even on the radar of the producers he visited.

“I ended up doing a lot of education with the people I was touring with,” he says, “because most of them either hadn’t heard of Washington state, or had no idea that we make wine here. In so many ways this trip was an amazing and life-changing experience.”