Are your Boost Flavours Gluten Free Kelsey August 03, 2020 10:56 Updated Yes. All our Natural Beer Flavour Boosts are gluten free. Related articles What is in the Cider Essence and Sweetener? Which countries do the fruit concentrates in Mangrove Jack's Ciders originate from? What are beer finings? Instructions - Dual Temperature Controller Can brown sugar be used with the kits?