Crema is the foam that forms on the surface of the espresso during extraction. Its formation is influencing by the processing method, extraction, and the freshness of the roast.

To make delicious coffee, it must be fresh. Old coffee has a flat, expressionless taste with an unpleasant bitterness. It is because, upon contact with air, coffee quickly exhales and ages. This article explains why and what to do about it.

After roasting, coffee rapidly loses its freshness: the taste becomes flat, unpleasant rancidity appears. We talked about this in the article about the freshness of the coffee. The reason is that roasted coffee is very hygroscopic: it quickly absorbs and gives off moisture, takes on odors and, to put it simply, is exhaled, and the essential oils in the beans react with oxygen and oxidize. For keeping coffee fresh longer, store it properly.