Be careful about the five year rule as above and here. The rule says TTB formulas expire five years after approval. Not all formulas. Just the ones for imported products such as vodka, sake, and liqueur for example. This is in substantial contrast with TTB label approvals, permits, and domestic formulas. Generally speaking, they don’t expire unless the applicant changes something.
In our experience, TTB tends to explain the expiration date on the relevant formula approvals, but not in the regulations or widely elsewhere. An example is here. It can come as an unpleasant surprise, if you are seeking a new label approval more than five years after issuance of the formula approval, as in the case above. In the time period about 5-8 years ago, TTB would frequently allow a use-up in some cases where the formulas was expired. But, as suggested above, use-ups are much harder to get, in more recent years.