best ways to store tinctures?

I love making tinctures and rarely need to use them.  I like knowing they are there though just in case.

At the moment I have mugwort, usnea and quite a lot of echinacea tincture set back.
Would they keep longer refrigerated?
They are in a cool dark cupboard but summers here are very hot and so is my house where 'cool' is relative.

thank you so much Dr. Tilgner for being here and sharing so much information!

When I owned an herbal company we had to heat the place and cool the place most of the time to keep the herbs in good shape, including the tinctures. We did not let them get above 75 F. In my home, I simply keep them in the coolest part of my house, but my house is never over 75 usually either in the summer. I am not sure how hot your cupboard gets.

Sharol Tilgner wrote:When I owned an herbal company we had to heat the place and cool the place most of the time to keep the herbs in good shape, including the tinctures. We did not let them get above 75 F. In my home, I simply keep them in the coolest part of my house, but my house is never over 75 usually either in the summer. I am not sure how hot your cupboard gets.

We don't have air conditioning so I think after several hot days the cupboard is no longer cooler than the house, so low to mid eighties is likely.
...and in the winter the room with my herbs does not freeze but is often in the forties.

Would storing in the refrigerator be better year round and avoid the temperature swings?

They usually are fine in the cold if it does not freeze. The heat can alter them. Look for changes in sediment. Is there sediment in the bottom that was not there before? Note any changes in thickness or changes in smell. They will probably be fine at 80 degrees. I have never noticed the exact point at which they start reacting from heat exposure. Sorry, I did not pay closer attention.  Tinctures are pretty long lived. I found about 40 bottles of tincture from the 1950s in an old pharmacy shelf when I took over the National University Of Natural Medicines clinic pharmacy back in the late 80s. We went through them and found many of them were still useful. We were really surprised.