Shouldnt be but Horchata is not really a flavor you can use alone . Maybe its the PG/vg your using? I havent got a hint of anything chemically or perfume in them . I would say maybe bad batch but they dont use perfumer ingredients in making them . Hmm 8% is low too which makes it even more strange that you would have a chemical taste. They do need steeping before the flavor comes out but as a single flavor juice it shouldnt change much.I mixed the Horchata at 8% (according to your suggestion) and it was very perfumey/chemical ,and stayed like that. The Choc. Glazed Dognut and Milk Choc Toffee were perfumey at first , but turned out very nice after couple of hours.