These are similar to the containers I use to rehydrate dry yeast (see tip 1 on the tips page).
Made of polypropylene. Autoclave safe container and lid. At $18.46 these are marked down 62%.
Nalgene 2118-0016 Polypropylene 500mL Wide-Mouth Straight-Sided Jar (Pack of 6) - $18.46 + Free Shipping with a $25 order