A few months ago I began noticing that my pizzas weren't tasting as good as they usually did. This was quite disconcerting. I hadn't changed my process, I was still using the exact same flour, the exact same sauce, the exact same yeast, and the exact same oven. But my pizzas tasted wrong.
A couple of weeks ago I brought Marvin out to a party on Bainbridge Island and made a bunch of pizzas. It was off. I doubt anyone noticed, but I did.
Last weekend I had the in-laws and some other folks over for pizza, and after everyone had gone home I mentioned to Kirstin that the pizzas didn't seem to taste right. She agreed but she wasn't sure what was wrong either.
What the heck was going on? Nothing had changed, except… time. Had my yeast gone bad? I didn't have any real reason to suspect it. It raised the same as it always has and that's how you know it's gone bad, right? If it isn't raising, throw it out.
The test is easy. Just order some new yeast and make two batches of dough using the exact same ingredients— but give one the older yeast and one the newer. So that's what I did and set aside the dough till the next morning.
Seventeen hours later (after the first raise) I couldn't tell any difference between the old and new yeast based on the amount it raised overnight. I was really expecting the newer yeast to raise higher. Doubt began to creep into my mind.
I balled the dough into individual pieces, set them in their little buckets, and waited another eight hours till pizza time.
Again, I was really expecting the newer yeast to raise more than the old— but the opposite happened. The older yeast balls were actually taller than the newer ones.
W. T. F.?
OK, OK. It's the taste that matters. So lets shape one of the old balls first, make a margarita pie, cook it, and taste. And… yep, it's still missing something. But that's expected— it's the yeast I've been using for months.
OK, now onto the smaller but newer yeast ball. Why is it smaller again?
Right away I noticed something different. The dough ball was smaller because the gluten strands were holding tighter. It certainly had more spring to it as I shaped it for toppings. Is this good? It'll certainly cause more bubbles on the edges if the gases have a harder time getting out. So yes, it's possibly a good thing.
How did it taste? Holy shit— this is what I remember. This is the good crust and this is what I was missing for months. The crust on this dough was lighter and had better structure to it. And it tasted so much better. You can see in the pic above (which is not the second margarita because I forgot to take pictures of it before it was eaten up) that the dough has more pop. It even seemed to leopard better.
Yes, my yeast had gone bad. It was still raising, but it was doing something wrong to my dough.
I'm so glad I got this figured out. It was really starting to worry me.
So how old was the yeast I was using? It was from May of last year. Clearly 12 months is much too long, and I think I'll be ordering new yeast every 6 months. And what yeast do I use? 16 oz Saf instant yeast.