I got natural yeast from my local bakery. People buy less bread and such so they still have a lot of yeast they won't use and the shelf life is only 20-30 days

I got natural yeast from my local bakery. People buy less bread and such so they still have a lot of yeast they won't use and the shelf life is only 20-30 days so they started selling the yeast they buy wholesale. Huge 2kg brick. Used a bit but put the rest in the freezer.