Is my instant yeast still good?
Hello,
I'm a new baker, just started 2 weeks ago. I have 2 different brand of instant yeast:
Yeast A: bought in sealed pack of 7gr, the remaining is kept in freezer. It has light sourish/pungent smell, almost fruity. Expiry date is May 2022.
Yeast B: bought from a wholesale store. In the store, the yeast is kept on a large, clear airtight glass jar. I got a small amount in a small clear jar, stored at room temperature (range 25-29 deg C). Smells bready, not as sourish as Yeast A.
I used Yeast A on the early bakes. I like the smell of Yeast B, so I've been baking with it for 6 batches or so. Both yeasts gave good rise during bulk fermentation and proofing, but it has poor oven spring and usually less texture. It might be due to multiple factors (kneading, room temperature, oven temperature), but I also had suspicion on the yeast.
I tested both yeasts using the same measurement: 50ml watear at 40 deg C, 5gr sugar, 1gr yeast.
Yeast B has very, very minimum bubble despite of good rise during proofing.
Yeast A, both from the newly opened sachet or the leftover from freezer, yield similar froth. It's far different from what I saw on the internet where the instant yeast can double in volume.
Is the result from the yeast test normal, given the quantity of water/sugar/yeast? Can different brand of instant yeast contribute to different result, e.g. due to different quality of the yeast?