Costco's Kirkland Signature Grass-Fed Butter Changed In 2026 — Here's How
Costco's Kirkland Signature Grass-Fed Butter has been a warehouse staple for years and a fan favorite of shoppers who love premium European-style butters and Kerrygold, which is Bobby Flay's go-to butter brand. Lately, though, fans have noticed something different about Costco's butter. This year, it has a new country of origin, moving from New Zealand to Ireland, along with a new manufacturer.
When the butter first launched in 2021, Costco worked with Westland Milk Products in Hokitika, New Zealand, to manufacture it. That changed in 2026. A Kilkenny-based dairy co-op, Tirlán, now supplies the grass-fed butter for Costco's Kirkland private label. Tirlán is also the co-op behind Truly Grass Fed, who makes our favorite store-bought cheese.
Additionally, the butter's packaging, shape, and labels have also changed. These changes have sparked plenty of conversations online. "Kirkland grass-fed butter is a different shape now," one Reddit user noted. The package still holds four 8-ounce bars, but they're now longer and flatter, closer to Kerrygold's brick-like blocks.
Shoppers feel mixed about Costco's changes to its Kirkland Signature Grass-Fed Butter
Another Redditor on the same thread, who uses the butter to make ghee, said the New Zealand version of Costco's grass-fed butter "was always amazing" and worried the new one might not perform the same way. "So to me this is a huge downgrade," they added. A fourth commented, "Hopefully this is just a temporary thing with the new packaging/rollout."
As for taste, at least one shopper on the Reddit thread didn't notice much of a difference. "Basically the same," they wrote. "We blind tested it against the [Kerrygold] we pulled out of the freezer and it wasn't any better or worse. They weren't identical but one wasn't better than the other." One commenter was even a fan, stating, "This [Costco butter] is the best butter. Just had some on toast with breakfast an hour ago. And melted, it's amazing on popcorn!"
Redditors agree that Costco's Kirkland Signature Grass-Fed Butter is still a good deal. It sells for $10.99 per four-pack, about $4 to $6 less than Kerrygold's, though prices will vary by region. If you have doubts about this new butter at Costco, see how other options stack up in our ranking of popular grocery store butter brands, then grab a box and taste-test it for yourself.