Sorry, I thought this was a general propagation forum, but I just realized it is rose specific after I posted my question! Sorry if this is not the right place to ask it.

I don't think that I used your compound but certain rooting hormones like the gel do age. I bought one bottle that had to be old because the color was different form the previous, fresh one and I could not root any rose with it while the fresh gel (bluish purple color) rooted me 95% of the cuttings or more.
I used another liquid type rooting hormone with a high failure rate so I assume that again that product was sitting too long on the vendor's shelf prior to my purchasing it.

The last time I purchased a rooting gel from UK where they emphasized that the gel was fresh and it is fresh indeed. Interestingly enough it cost me half of the price that any US vendor would have charged me for the same product or smaller bottle with over seas delivery included.

I keep it in the fridge.