The New Zealand Brand That Makes Costco's Grass Fed Butter

If you've been shopping at Costco, you might wonder where its butter comes from, and if you happen to be wondering about Costco's Kirkland Signature Grass-Fed Butter, specifically, this is the place to be. While it didn't make the list of the best and worst butter brands to buy from the grocery store, Costco's Kirkland Signature Grass-Fed Butter, which launched in 2021, and the brand behind it, deserve a moment in the spotlight. Westland Milk Products, based in Hokitika, New Zealand, is the partner behind Costco's grass-fed butter. With regional ties going back over 150 years, Westland Milk Products relies on its historical connection between the farms and factories that produce their butter.

While you're busy spreading that room-temperature butter, you may also be wondering other things about it, like when to use salted versus unsalted in baking. Or, you might wonder how it's made. Usually, buttercream is separated from raw cow's milk, pasteurized, aged, then churned. As the buttercream churns, fat clumps up into chunks of popcorn butter. These clumps are then separated from the remaining buttermilk and churned some more until it looks more like the yellow butter you have in your fridge.

Hamish Yates, general manager of sales and marketing at Westland Milk Products, notes that this butter enhances the flavor and texture of the dishes it is used in, and that its natural richness is worth savoring. The grass-fed lifestyle of a cow causes the butter it produces to have a richer, more buttery flavor than it would with other diets. When compared to other brands, a Redditor found Costco's grass-fed butter to be darker in color and richer in taste — likely due to the diet of the cows — noting "The Kirkland came out on top."

The cows supplying the milk for the butter are from about 400 local New Zealand farms and live off a diet consisting of 95% grass, with the rest of it being GMO-free supplemental grains. Unless it is wintertime, milk is collected from the cows daily and transported to the Westland Milk Products factory where it is used to make butter. Grass-fed butter like this is healthier than regular butter because it has a higher proportion of healthy fatty acids and more vitamins. Now that you know the signature behind the Kirkland Signature Grass-Fed Butter, you can enjoy it a little more with your toast.