Wayyyy past Expired dry yeast: Toss it or pitch it?

So I was digging through some old home brew equipment and found a nice surprise box with about a dozen packets of dry red star and Nottingham ale yeast. Come to find out I bought these back in 2007 and the expiration on them showed 2009 to 2010.

Was wondering these still may be viable for use even way past expiration? They're still sealed and have been sitting in my basement this whole time.

Even though it is cheap to replace, I'd hate to toss something if it still good to use.

2 choices.

Choice 1 - use mrmalty or a similar calculator to estimate viability. Then depending on what you find, make a small starter a day or 2 before brewing to ensure they are still alive. Also use mrmalty to approximate pitching rate.

Choice 2 - dose your boil kettle with 1/2 pack or so of the dried yeast per 5 gallons around 10 min before the end of the boil and let your fresh yeast use it as nutrient.

Throw one is some starter wort and see what happens I Would be shocked if there is 0% viability

^^^ Make a starter. That's your test for viability and ramps the cell count up.

I recently made 2 batches using S-05 with an expiration date of 2010. They had always been stored in the freezer.

For all security I made starters and they both worked fine.

Giving the starter a shot, lets see what happens!

Hm good news. I used some malta goya and cut it with 50% water, measured an SG of 1.030. Pitched the red star montrachet into 16 ounces of starter and after 12 hours ended up with a nice head of krausen, checked the SG after 24 hrs and it was floating around 1.010--- I think they're good!