When making your preparedness plan, if you don’t know how long something will last, it’s difficult to know how much to store.
What I’ve found that works well for me is to take a marker and write the date on the package when I open it. Then, when that item is used up, I can look at the date and know how long it lasted me. I write these durations in a log and refer to it when I’m trying to plan on how much to store for a certain period of time.
Recheck these dates periodically to keep on top of any changes in the rate of consumption.
You should also get into the habit of writing the date on anything consumable that doesn’t have an expiration date on it. This way you’ll be able to keep track of how old it is.