Walnut oil from Huilerie de Moulin de L’ile in the Bourgogne region of France. Photo by Christine Burns Rudalevige

I tell cooking class students in Maine that I don’t spend much money on pricey unrefined nut oils from away. When a salad dressing recipe calls for one, I just take a half cup of shelled, raw nuts and simmer them gently in 1/3 cup neutral cooking oil. The result is a twofer: a handful of nicely browned nuts I can toss into the salad for texture, plus a manageable amount of flavorful oil I can easily use up before it turns rancid.

I must now eat those words, because last month I dropped 75€ ($81.18) on hazelnut and walnut oils from a mill I visited in the Bourgogne region of France, about two hours south of Paris. While the French nut oil purchase blows my food mile budget for condiments for the year, I’ve rationalized the purchase by homing in on the fact that everything about the production is completely sustainable. Plus everything about the mill was simply charming.

Monsieur Roger Coudray leads a tour of his children’s walnut oil press. Photo by Christine Burns Rudalevige

Take Monsieur Roger Coudray, for example. A diminutive octogenarian with dancing blue eyes and a fabulous plaid ascot cap, he greets us with open arms but very little English and tells me his children have owned the Huilerie de Moulin de L’ile since 2012. My transactional French exhausted, I tap the interpreting skills of my husband’s cousin who was traveling with us at the time to understand Mr. Coudray as he tells me local hazelnuts and walnuts have been pressed into oil here in Donzy (pop. 1200) since the late 19th century. The building was constructed circa 1820 to make nails, and has also been used to make cider and lemonade. All these operations were powered by the Nohain River the mill sits on, with the flow driving the same hydraulic turbine at a rate of 500 liters per second.

The picturesque Huilerie de Moulin de L’ile, a walnut oil press in the Bourgogne region of France. Photo by Christine Burns Rudalevige

The picturesque spot, further dramatized by lilting willow trees and the aroma of toasted walnuts floating on the breeze, is magical. Queue the elegant white swan that glides over to Coudray and looks up at him expectantly. The man tosses the bird a handful of dry, brown-gray powder, explaining as he does so that it’s a nutrient-dense byproduct of pressing the oil out of nuts. It resembles the peanut butter powder products on the low-fat food market in the United States. While the bird laps up the offering, the man says most of the walnut and hazelnut powder from this mill goes to feed local livestock. The Coudray family also owns a duck and goose farm down the road from the mill.

Swan sated, Coudray ushers us through the backdoor of the mill. He raises his voice above the din of a large compressor pulled from an old steam ship to explain that it drives a series of belts running above our heads that make the various parts of the oil-pressing process possible. We walk past a large bin of kernels (raw, shelled nuts) brought to the mill by residents who live within 100 kilometers of the mill who’ve harvested, dried and shelled them. The Coudrays also source nuts from Loiret (100 kilometers to the east) and Lot-et-Garonne (600 kilometers to the southeast), based on supply and demand. It takes 1.7 to 2 kilograms of kernels to make one liter of walnut or hazelnut oil, and theirs has won accolades around France for its flavor.

Time-honored machinery at the Huilerie de Moulin de L’ile walnut oil press. Photo by Christine Burns Rudalevige

As a first step in the oil-making process, the kernels spend 15 to 20 minutes getting mashed to a pulp by a 2.2-ton rotating millstone made of yellow stone pulled from a local quarry. The paste is then heated to draw out some of the moisture from the nuts, a step that both yields a specific flavor and helps preserve the oil once it is bottled. Unrefined nut oils like this can be stored for up to six months in the refrigerator once the bottle has been opened. They can sit unopened on a pantry shelf for up to two years.

Twenty-kilogram bags of the toasted nut paste are carried by elevated conveyor belt to centuries-old presses where 30 tons of pressure is applied to squeeze the oil from the paste. Spectators (the mill is open most days) can watch the whole process up close. The only health and safety warning I saw posted was on the front of the presses. It read “Please stay away from the workstations. Watch your children.”

Armed with a spoon, though, I ventured around to the back of the press, and stuck it into the stream of oil. It was warm, fragrant, smooth and tasted of perfectly roasted walnuts. It was really nothing like my own kitchen-hack nut oil in Maine. That stuff is a fine substitute. But the real deal, made sustainably in small batches from a local, raw ingredient, simply can’t be beat.

I gave most of the oil I bought in France to the friends and family who hosted us there. I have but one 100-milliliter bottle to bring home with me, but it’s likely going to be one of those culinary luxuries I’m not willing to share.

If you’d like to get a bottle of your own, I am sure Monsieur Coudray will welcome you to his family’s mill whenever you manage a trip there.

Corn, Green Bean and Grain Salad with Walnut and Lemon Dressing. Photo by Christine Burns Rudalevige

Corn, Green Bean, and Grain Salad with Walnut and Lemon Dressing

Unrefined nut oil should not be heated because it will lose much of its distinctive flavor. It’s best used in salad dressings like this one.

Serves 4-6

FOR THE DRESSING:
1 tablespoon minced shallots
1 tablespoon lemon juice
Pinch of salt
½ teaspoon Dijon mustard
3 tablespoons unrefined walnut oil

FOR THE SALAD:
2 cups cooked whole grains like farro, wheat berries or barley
1 cup fresh corn kernels
1 cup fresh green beans, blanched and chop into 1/2-inch pieces
1 red bell pepper, seeded and chopped into 1/2-inch pieces
1/4 cup chopped flat-leaf parsley
2 tablespoon chopped fresh chives

To make the dressing, combine the shallots, lemon juice and salt in a small jar with a lid. Let them sit together for 15 minutes. Add the mustard and walnut oil and shake well to emulsify the dressing.

To make the salad, toss the remaining ingredients together in a bowl. Add the dressing and toss well. Let the salad sit for 15 minutes before serving at room temperature.

Local foods advocate Christine Burns Rudalevige is the former editor of Edible Maine magazine and the author of “Green Plate Special,” both a column about eating sustainably in the Portland Press Herald and the name of her 2017 cookbook. She can be contacted at: cburns1227@gmail.com.