What is cultured butter?
Cultured butter is a “throwback” of sorts. Before pasteurization existed, cream naturally curdled before it was made into butter. These days, cultures can be added to pasteurized cream to mimic the flavors and chemical qualities of yore.
“European style” refers to the fact that Europe requires a higher butterfat content in all their butters (82 percent versus 80 percent in the US). Depending on the company, this has different interpretations about the exact percentage.
Why do we care?
Flavor! As you may know from eating other foods with live bacteria added (yogurt, kefir, kombucha, kimchi, etc), there is a great amount of flavor provided from the cultures. Additionally, the slower process results in a higher percentage of butterfat (usually 82-86 percent).
This may initially make you think, “Oh no, it’s less healthy!”
But let us first acknowledge that butter is not a health food. Nor is it an evil food. It is delicious and it contains calories and should be used in moderation.
Fat is flavor! If something is more flavorful, you may use less on your toast, potato, etc, and thus the slightly higher fat content evens out.
Fat may help you to eat less because it enhances satiety (makes you feel more satisfied with what you ate). This is not an endorsement to go grab a bag of potato chips, but if you love your broccoli with butter on it, consider that this may help you eat your vegetables and feel more full afterwards.
Higher fat is higher quality. Ice creams are ranked by their percentage of fat, in part because it reduces crystallization, and this helps them taste better. Higher fat butters, likewise, taste better and can enhance baked goods due to a lower water content.
(Why? Water can activate gluten, which is not desirable in baked goods other than bread. Additionally, butter may stay solid longer before melting, which helps create air pockets within a dough or crust throughout the cooking process. These turn into flakey and tender properties in the final product.)
To learn more, check out this thekitchn.com piece on butter.