The most interesting class I have taken at the annual conference of the International Association of Culinary Professionals, meeting this week in Chicago, was on butter — my most favorite food. (Remember, everything tastes better with butter!) Here is what I learned:

Butter can be sweet or cultured. A culture can be added to the butter or the butter can be cultured and ripened. A cultured butter tastes best when the flavor is fully developed after a three-month aging period. Plugra, an American-made butter which we sell at Kitchen Conservatory, is a culture-added, unsalted butter with 82 percent fat. So much for freshly-made, sweet butter, which can taste rather bland.

Salt can be added to either sweet or cultured butter. Salt prolongs shelf-life (particularly in sweet butter), and is a flavor choice. Usually 1-2 teaspoons of salt is added to a pound of butter. Although pastry chefs usually sneer at salted butter, one of the most interesting butters I tasted was a cultured butter from Vermont Butter and Cheese Company with lots of coarse sea salt crystals folded into the butter. I licked the plate.

Butter is naturally 82 percent fat. The US government regulates that butter must be at least 80 percent fat. So most American butter manufacturers add water to their butter, so that the fat is reduced and the amount of butter to sell is increased. The butter from the Vermont Butter and Cheese Company is 86 percent fat.

The color of butter traditionally comes from what the cows eat, so small-batch butter makers have butters of many shades of yellow. Larger companies pool their cream to create a uniform, year-round color. Color is not an indication of quality. The palest butter I tasted was a pure white butter made from goat’s milk. It was sensational.

One of the speakers was the director of the Butter Museum in Cork, Ireland. Now there’s a field trip!