Aldi itself has over 2000 locations in the US where you can buy Irish grass fed butter. Lidl has around 167 locations in the US where you can also buy Irish gra

Aldi itself has over 2000 locations in the US where you can buy Irish grass fed butter. Lidl has around 167 locations in the US where you can also buy Irish grass fed butter as a reasonable price. Kerrygold is the most popular Irish grass fed butter in the US but it is not 100% grass fed. It is around 90% grass fed currently. The amount of grass feed has reduced over the years as demand for the butter has increased. The cows are fed soy and corn to supplement the grass. As noted in your edit Costco sells grass fed butter. They have two options. One is Kerrygold and the other is their own Kirkland Signature brand. The Kirkland Signature is 95% grass fed and imported from New Zealand.