What are Mangrove Jack's Hard Seltzers? Simply explained Hard Seltzers create a fermented home brew alcoholic sparkling spritzer style drink. They are typically clear in appearance and with an ABV of around 4% with selected fruit flavours. Unlike carbonated wine based spritzers Mangrove Jack's Hard Seltzers are low-calorie, natural, zero-carbs, low in sugar, gluten-free, and suitable for vegans. Often perceived as a healthier alternative to traditional alcoholic spritzers and other alcoholic beverages. They are light and refreshing with the possibility of unlimited flavours. They are offered in a handy Hard Seltzer kit.