Must (from the Latin vinum mustum, “young wine”) is freshly pressed fruit juice (usually grape juice) that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace; it typically makes up 7%–23% of the total weight of the must. Making must is the first step in winemaking. Because of its high glucose content, typically between 10 and 15%, must is also used as a sweetener in a variety of cuisines. Unlike commercially sold grape juice, which is filtered and pasteurized, must is thick with particulate matter, opaque, and comes in various shades of brown and/or purple.

I must write to her. I haven't written to her for ages!			Debo escribirle. ¡No le he escrito por mucho tiempo!
I really must stop smoking.			Debo en verdad dejar de fumar.
You must be here by 10 o'clock at the very latest			Debes estar aquí para las 10 en punto a más tardar.
We don't have much time. You must hurry up