Must was created by Harry Roberts and his father Robert Roberts in 1910 as a non-alcoholic alternative to beer. The syrup is still made exclusively by Roberts AB in Örebro. The original recipe is said to be locked up in a safe with only one person knowing the full recipe.
Must is made of carbonated water, sugar, hop extract, malt extract, spices, caramel colouring, citric acid, and preservatives. The hops and malt extracts give the must a somewhat beer-like taste, but much sweeter and, since it is not fermented, it contains no alcohol. It can be aged provided it is stored in a glass bottle. Some people buy must in December only to store it a year before drinking it