The Maker Behind Costco's Kirkland Signature Grass-Fed Butter

When most people think of Costco, they probably think of low prices and large quantities. However, the popular warehouse retail club is also one of the best places to find high-quality store brand versions of everyday products at affordable prices. Among them is Kirkland Signature's grass-fed butter, a premium dairy product renowned for its nutritional benefits compared to those of typical butter. As with many Costco specialties, the company teamed up with a well-known producer to bring the grass-fed butter to its shelves.

Kirkland Signature grass-fed butter is the result of a partnership with New Zealand's Westland Milk Products, which collaborates with around 400 farms across that country to produce around 120,000 metric tons of products annually, which are sold in 40 countries around the world. The company has been around for more than 150 years and maintains old-school methods of butter production such as the European Fritz churn method, which uses augers and mincing plates to double the fat content of the butter during processing.

Westland has been partnered with Costco to produce its grass-fed butter since 2021. The two developed extensive processes to ensure all milk comes from cows fed at least 95% grass, with the remaining 5% of feed free from genetically modified organisms or growth hormones.

Those who aren't super familiar with dairy might wonder what the big deal is regarding grass-fed butter. Although the taste is similar to that of traditional butter (allowing for easy substitutions between the two), Westland has noted to Costco the vital health benefits grass-fed butter can provide when eaten in moderation, including more vitamins and omega-3 fatty acids as well as cardiovascular, immune, and anti-inflammatory support. The grass feed also creates a distinctively bright yellow color from the high amounts of beta-carotene, resulting in a butter that's as beautiful to look at as it is delicious to eat.

These high-quality processes and health boosts haven't gone unnoticed by Costco shoppers. This grass-fed butter made our list of the best Kirkland dairy products to buy at Costco, and our reviewer pointed out its similarities to popular, high-end Kerrygold butter — with one exception. Kirkland's butter is cheaper. It's worth noting that Kerrygold earned the number-one spot when Mashed ranked 16 popular butter brands, so the comparison is a highly positive one. While there may not necessarily be a huge name brand hiding behind this Kirkland product, bakers, chefs, and other dairy aficionados can still rest easy knowing a high-end producer like Westland is crafting Kirkland grass-fed butter.