Approval of process and entry of premises (producers): How can a producer denature alcohol? - Standard method
Producers may mix the alcohol, marker and denaturants in a mixing vessel by whatever means they wish, provided the resulting product consists of a mixture conforming to one of the authorised denatured alcohol formulations.
Producers holding residual stocks of denatured alcohol in a tank may wish to use that tank for further denaturing operations. In such circumstances, you may approve the adding of alcohols to the tank for immediate denaturing, provided the producer takes account before and after the addition of alcohol to the vessel.