Poppers are at their best when kept in the freezer - unopened. That´s how we keep them in our store.
Expiration - you can keep them unopened in the freezer up to a year, quality won´t change.
But we advise you to use it ASAP as some leaking may occure later on.
Once opened, keep them in the fridge, possibly in some glass jar to prevent odour in the fridge.
Again - use it ASAP to prevent leaking or effect reducing.