What Is Walnut Oil?

As far as edible oils go, walnut oil is one of the least used, mainly due to its high price and the bitterness that can occur when heated. It's wonderful when used as a finishing oil on foods served at room temperature, but it's also an elegant addition to a cold dish. Walnut oil imparts a slightly sweet, nutty essence that works well with chilled noodles, aged cheeses, and hearty vegetables. Find it with the other special nut-based oils in the grocery store, and learn how to incorporate this ingredient into meals.

What Is Walnut Oil?

Walnut oil is made from walnuts that are pressed until all oils have been extracted from the nuts. It's a golden brown oil with a sweet, nutty flavor that becomes slightly astringent when heated too much because walnut oil is an ingredient with a low smoke point. It's really not a cooking oil that you want to use over high heat.

There are many ways to make walnut oil. The cheaper version involves macerating walnuts into a neutral and inexpensive oil base such as canola oil. This isn't necessarily true walnut oil, but instead an infused version. The expensive variation comes directly from the nuts, which are dried and then cold-pressed or expeller-pressed, and then heated.

Although walnut oil is delicious to use on food, its uses go beyond that. It's also been used to finish wooden bowls and utensils as a food-safe varnish to keep the pieces in good condition and prevent cracking.

Walnut Oil vs. Olive Oil

Everyone knows olive oil as the cooking oil used to roast vegetables, make sauces, pan fry a delicate fish, or to dress a salad. Walnut oil can't be used in all of those ways, but it is especially good in situations where you don't have to heat it to a high temperature.

Like olive oil, walnut oil can impart a bit of the place it comes from, whether that France or California, two places that are known for growing walnuts, for example. It's more expensive than olive oil, which is another reason it's not seen in as many dishes. Overall, olive oil proves more versatile, but walnut oil offers a unique flavor and adds a subtle nuttiness when it's used.

Varieties

The best walnut oil out there is the unrefined, cold-pressed version, which is more expensive but features 100 percent walnuts. This type retains most of the oil's nutrients and offers a delicate flavor best for cool and room temperature applications.

The second tier of walnut oils is refined. The walnuts are expeller-pressed and saturated with a solvent that extracts the most oil, but then the oil is heat-treated to remove the solvent. The third and cheapest tier of walnut oil is actually vegetable oil infused with walnuts, which may give the product some similar notes but won't carry the same nutrition, aroma, nor heating restrictions.

Walnut Oil Uses

Drizzle cold-pressed walnut oil onto a hearty salad for a burst of nutty warmth. Or take this condiment for a spin over wild rice or a piece of perfectly roasted fish. Although it's more of a finishing oil than something to cook with, it's possible to use for gentle sauteing or as a substitute for other oils in baking (especially if you are looking to impart a slight walnut flavor). When cooking with walnut oil make sure to keep the heat low; if it gets too hot the oil becomes bitter.

What Does It Taste Like

There's a slight woody and nutty note to this amber-colored oil. Its delicate taste makes walnut oil a great finishing condiment or one that works well used on salads. It's especially good at bringing out the deeper flavors in squash, aged cheese and dark leafy greens.

Recipes

Walnut oil can be a tasty finish to many foods, though it's not the best for cooking with. Try it in lieu of other oils in some of these recipes, or even on its own, drizzled on top of a salad or with fresh bread. You may find that it goes especially well with French food: it's said walnut oil first made an appearance in rural cuisine and the Dordogne Valley produces the most in the whole country.

• Broccoli with Garlic and Red Onion
• Cold Soba Noodle Salad
• Mediterranean Chickpea Salad

Where To Buy Walnut Oil

Some larger mainstream supermarkets may carry it in the specialty oil or organic section, but it's also often found in small gourmet shops and definitely available online. Read labels carefully to determine whether it's refined or 100 percent pure walnut oil.

Storage

Keep the bottle of walnut oil sealed until ready to use. Once it's opened, walnut oil will keep for 6 to 12 months as long as it is sealed and in a cool place, out of sunlight.