Yeast - how old is too old?

I’ve got 3 packs of yeast. One super fresh, one that’s just about past it viablity date, and one that is way past being viable - it’s so far gone it’s changed colors.

When doing a 1L yeast starter, would it help, hurt, or not matter if I pitch all three?

They’re all the same strain from White Labs.

The first two are fine. I wouldn’t pitch the one that has changed colors. I’m guessing it’s gray? That means it’s mostly dead yeast, which tastes terrible. That off-flavor could carry over into the beer. It’s still useful, though–you should taste it to learn what autolyzed yeast tastes like.

If you’re just making a 1L starter I’d either use the older, but still viable one and save the fresh one, or just use the fresh one and toss the other two. You won’t gain anything by pitching more packs into a 1L starter.

As far as the past date one goes, if you’re really frugal you can try to save it by making a starter with it, letting the trub start to settle, then decanting the liquid portion only into a new starter. It’s not a surefire method, but I’ve used it with some success for things like limited release strains that I forgot about and can’t get any more.

I’m going to use the still viable pack in a starter and save the fresh one. I’m using wlp095 Burlington Ale for an IPA tomorrow. I’m intrested to see how that yeast strain would work in a wheat beer.

Thanks for the help!