My mom got a box of thread from a neighbor moving into a retirement home. She would like to give some to me but I'm not sure how old it is. Is there a test you can do to see if the thread is still usable? The lady did some quilting and some of the labels look fairly recent, but I would hate to sew something only to have it fall apart after washing because the thread all broke! Have you any suggestions to test its strength?

The first thing I would try would simply be to pull on it hard and see how easily it breaks. If it is old and brittle it will probably snap very easily.

That is how I test thread too :D:D:D

It also a good idea to keep you threads in a drawer and out of the dust as this will make it weak. I spray my threads with water now and then or silicone....

I was told at a quilting class that if it is on a wooden spool it is too old to use.

Some of that old thread on wooden spools is still good. I do the snap test. If it breaks easily then I unwind a full layer and try again. If that one breaks easily throw it away or if it's on a wooden spool I glue the end of the thread down and use it in a glass bowl for decoration.

I would be particularly suspious of wooden spools. I once made a lined Blazer with a spool of thread given to me from my grandmother.... and the thread shrunk! I had never heard of thread shrinking but this spool did .
I was broken hearted as it was a difficult pattern and the hardest thing I had attempted , at that time.

I just do the snap test or maybe sew a sample block and throw it in the wash a couple of times.

Nancy Zeiman says that old thread dries out and you can rejuvenate it by putting it in your freezer. Usually the black thread breaks the easiest and I tried this and yes it works. Try it what do you have to lose.

My quilter cousin told me that you can use that old thread for basting. It sure would save your expensive quilting thread for the real thing (quilting).