SPIR4250 - Technical guidance: But that's 'other fermented products' - what does that have to do with spirits?
Products which are manufactured with a spirit base are liable to the spirits rate of duty irrespective of what other ingredients are added to the base spirit. To produce these products a trader must have an excise warehouse approval and account for the spirits duty on a W5 or W5D.
More information about these products can be found in X-5 and Public Notice 162.