Hello, my name is Allen, I cook professionally, and I don't change out my seasonings as often as I should....
I know my pepper, thyme, tarragon, Old Bay, ground mustard, ground sage (homemade), and Chili powder are reasonably "new", as I go through them pretty fast. I have some large containers of spices and herbs that I bought from Sam's Club about 10 years ago. I also have some smaller jars of spices and herbs that I just don't use very often at all. So far, none of them have degraded that I can tell. I keep them covered, and in a cupboard away from light and heat.
I did pitch a small container of zest, either orange or lemon, a couple weeks ago. I just didn't like the looks of it. I need to go through my herbs and spices and decide what's worth keeping, and what needs to be pitched.
Now, my MIL had some jars of herbs and spices that had been on a spice rack, over her stove, for who knows how long. Most of the dried herbs no longer had any color. I'm guessing they were at least 20 years old, or older. She didn't use them, but refused to get rid of them. I think they probably belonged to my MIL's mother, and my MIL was holding on to them for the emotional tie. I think I made them dissappear when I moved my MIL's stuff into my home :)
Peace, Love, and Vegetable Rights!
Eat Meat and Save the Plants!