Baking: three year old yeast?

Self-tutoring about baking: the tutor mentions using “old” yeast to make bread.

I was off bread baking for awhile, for a few reasons. One was we didn’t have a working oven; another was a low-carb diet I was on. However, with both those obstacles cleared, I got back to baking bread last Thursday. I don’t know when the last of it got eaten, but there’s none left, so I guess it turned out all right.

I really like baking bread, and have written numerous posts about it (see my post from Nov 25, 2017, for instance). Yet, like any habit one leaves for awhile, it might take a bit of extra concentration to restart.

One situation that confronted me immediately last Thursday was the yeast: it had two different “use by” dates at different places on the jar. One said a date in 2019, the other, a date in 2022. Either way, it seemed to be way overdue. Moreover, it said on the jar something to the effect of “Use within six months.”

When one bakes all the time, and keeps using the same container of yeast, one might not care about such things; the yeast worked last week, so one expects it will this time. Intuitively, one might not expect yeast can lose function in just a week.

Yet, three or six years on, might yeast lose its activity? Not likely, I thought, so decided to proof it.

As it turned out, the yeast proofed fine; subsequently, the dough raised as it should have, and so on.

How yeast could have two use-by dates on it, three years apart, might be one mystery. Perhaps the whole situation is academic. However, the bread was real.