Morello cherries are a dark-coloured type of sour cherries, Prunus cerasus, used in cooking or canned rather than eaten fresh because of their sharp acidity. They are also processed into juices, liqueurs such as kirsch, jams, and pie fillings, and they give the classic Black Forest cake its signature layer. Their deep red color and tart flavor come from anthocyanins and organic acids, and processors prize them for holding shape and color through heating. Their juice is also studied for potential recovery and sleep benefits linked to its natural melatonin content, though such effects remain an active research area rather than an approved claim.