Need to make lemonade with mint for business but I can't find a store in Dumaguete who sells mint simple syrup that can be stored for weeks.
I would try Yan Yan, as well. Alternatively, if you can get fresh mint leaves there, the syrup is very simple to make and keeps for about a month or two. Several recipes are out there, they are all basically the same. https://www.allrecipes.com/recipe/247478/mint-simple-syrup/