Two things you may not know about me are: 1) I can be a penny-inching miser (comes from standing in food lines as a child) and 2) I grew up listening to the Dr. Demento Show (yes, I was a nerd).
When there was no activity, I first checked the must temperature. When that was in an appropriate range, I ran a little experiment:
I mixed up some water, sugar, DAP and StartUp powder. I divided this into three glasses. In one, I attempted to reactivate the RC212, in another the D47. In my “control” glass I reactivated some Fleischmann’s baker’s yeasts from a freshly-opened packet.
Sure enough, after a few hours, the Fleischmann’s was bubbling vigorously, while the other two mixtures were perfectly still after a few hours.
I had opened these packets of RC212 and D47 last October/November and then sealed them in zip-lock bags. It turns out that this method is insufficient for preserving yeasts. As a matter of fact, although these are freeze-dried yeasts, cool(-ish), dark, dry storage conditions are not enough to maintain their viability once the packet is opened.
Oxygen is the greatest enemy of freeze-dried yeasts. When I ordered some yeasts from Napa Fermentation earlier this week, it was recommended that I store the left overs of the 500-gram brick I will be getting either in vacuum-sealed bags, or in zip-lock bags into which I should first inject inert gas, and then squeeze out any gas. Refrigeration is an obvious plus.