Sekanjabin is a period cordial of Middle Eastern origin, similiar to the Greek medicinal drink "oxymel". Sometimes called "Persian mint drink" in modern descriptions. It is made with water, sugar, vinegar, and mint. The resulting syrup is diluted with water, 5-10 parts water to 1 part syrup, according to taste.
This is a good drink to bring to large camping events such as Pennsic. The syrup can be stored without refrigeration and then diluted on-site, providing 2-5 gallons/7-19 litres of drink for one standard bottle of syrup. It's portable, stores well, it's period, and tastes much better than Pennsic hose water.