Hi,
To keep things short and to the point, I've noticed my doughs don't rise very well anymore. I let doughs rise in my oven in fermentation stand, this keeps the oven at a stable 30 degrees C. I am using instant yeast that I have kept in an airtight concealer in the fridge. I have keeping this well over 7 to 8 months.
I tried a proof test in a small bowl 1/2 tbsp of yeast and 1/2 tbsp sugar and filled it with 32° C water. Stirred it gently and let it sit for 10 minutes. The result is as shown in the attached image.
Is it time to swap out this yeast?
It should be frothy in 10 minutes. New yeast is in order.
When I came back a few hours later, it did have a layer of white foam under a bit of drifting yeast. But yeah, I was already suspecting my yeast was getting too old.
Thanks for the confirmation!
edit: I just bought a new batch, trying SAF red label this time. Since last time I kept 500g of yeast in the fridge, I was never able to finish half of that with the amount of baking I do, even over the course of 8 months. So I wanted to check, can I store half of the pack in an airtight container in the freezer? If I can, how long does it usually preserve in the freezer before it loses effectiveness?
I have just checked the use-by date of two old jars I pulled out , one from the of the fridge , one out if the freezer .One is 2 1/2 years past , one 1 1/2 years past .
Two cups ,about 1/4 inch of room temp, water , a big pinch of yeast , and a big pinch of sugar in each , and a loose lid cover , 20 mins later they were foaming , so both seem to be ok .