If neither is ideal, why would either of them be mentioned in the recipe? To illustrate my point: "For coconut cream pie, ground beef or ceramic tiles can be used, though neither is ideal."

While grammar is important, one should place a higher importance on the overall meaningfulness of the sentence to begin with.

In this case, the author should have replaced this clumsy sentence with:

"Ideally this recipe calls for GIN, however, you may substitute with rum or vodka."