I bought a 500g S-05 package and i'm planning to use it only 20 g per week. Any advices on how to store it? it will last around 4-5 months
Your 500g pack will have a best before date, usually about two years after purchase date. Once you open the pack, transfer the contents to a similar sized plastic food container with a sealed lid, and store in your refrigerator. Mark the container lid with the expiry date. My experience is that your yeast will last at least one year beyond that expiry date.