The legal drinking/purchasing age of alcoholic beverages is 18. However because Mali is a predominately Muslim nation, many locals discourage anyone from drinking alcohol. There have been reports of locals and tourists alike being arrested and beaten for drinking alcohol.
Treat tap water with suspicion. It is often so heavily chlorinated that one suspects few bugs could possibly survive in it. But short-term visitors will be safer with bottled water. There are several cheap local brands, but be warned that they are only drunk by foreigners and wealthy Malians: don't rely on finding bottled water in shops patronised by "ordinary" Malians. Soft drinks such as Coca-Cola or Fanta are more widely available and safe. But remember that Coke will make you want to go to the toilet, and so may leave you more dehydrated than before you drank it - a serious problem in this stunningly hot country. Street vendors sell water and home-made ginger and berry drinks in little plastic bags. They are often iced which makes them very refreshing in the heat. Generally, you shouldn't drink these without treating them first. However, one which is called "bissap" in French and "dabileni" "red hybiscus" in Bambara, is made from hibiscus flowers that are boiled during preparation, and so generally is safe to drink. It is a particularly delicious non-alcoholic drink you shouldn't miss. In Bamako, it is possible to purchase at most corner stores treated water in small plastic bags for XOF50; these are much cheaper, and of course more environmentally friendly, than bottles. The bags are marked with a brand name; be careful not to mistake them for the tap water that is sold in unmarked plastic bags by street vendors. Also widely sold in this way is sweet milk and yoghurt, which are normally clean because the bags are industrially filled. Fresh milk can also be bought from buckets at the roadside in some villages, although it should always be thoroughly boiled before drinking as it can carry tuberculosis bacteria often Malians do this before selling, but it is safer to do it yourself or at least ask.