There used to be a wonderful plastics store, since closed, on Canal St.
in New York, that had glass jars from one ounce to one gallon.

Now there are always Mason jars. You can get them in capacities from
one half pint to a gallon or so. The search engines should let you find
where you can buy an inexpensive dozen or so.

The next time Gregor goes to Home Depot I'm also having him look for
screw top jars of the sort that he uses to store things like nuts and
bolts.

Maria