72 hours after the chill. The batch is opened for the first time since blending. We evaluate it briefly — blotter, then skin — and seal it again. We are not looking for the finished formula. We are looking for correctness.

The 72-hour evaluation is a diagnostic check, not an aesthetic one. At three days into maceration, the formula is still raw — the ethanol, concentrate, and fixatives have barely begun to integrate, and the impression on skin will not resemble the finished product. What we are checking: whether any material in the London blend was added at an incorrect ratio (a dominant imbalance is already apparent at 72 hours), whether there are any signs of chemical instability that the −89°C chill did not remove, and whether the three-act structure is directionally present in its rough form. The question is not 'does this smell good?' The question is 'is this developing correctly?'

WHAT WE DID

The 72-hour evaluation protocol is consistent across every batch: blotter applied, evaluated at 15 minutes, 45 minutes, and 2 hours. Skin applied simultaneously, evaluated at the same intervals. If the evaluation is clean — base structure directionally present, no unexpected imbalances, no off-notes or instability — the batch is resealed and the next evaluation is scheduled at 4 weeks. If a problem is identified at 72 hours, it is addressed before the maceration continues. An error caught at 72 hours costs far less than one discovered at week twelve.

WHAT COMES NEXT

4-week evaluation — the mid-maceration integration assessment. By week 4, the ethanol, concentrate, and fixatives have been integrating for a month. The three acts should be readable in a form that resembles the finished formula for the first time.