The USDA defines empty calories as calories that come from sugars and solid fats, such as butter and shortening.

美国农业部将空卡路里定义为来自糖和固体脂肪（例如黄油和起酥油）的卡路里。

You separate the buttermilk from the solid fats, which would be the butter, and cultured is when you take that cream and you inoculate it with bacteria and yeast.

你把酪乳和固体脂肪分开，这就是黄油， 培养是当你取出奶油并用细菌和酵母接种它时。