It’s time to have a talk about when your milk actually goes bad (and no, the machine with the date stamp doesn’t actually know for sure).

And since 90% of Americans throw out food that’s still good based on the stamp, this is a really important conversation, you guys – and it honestly depends on how your state handles things.

Some states require a sell-by date, which indicates when the milk should be sold by and is intended to give people time to enjoy the product at home. Other states use a date that’s meant to indicate when the milk is believed to be at peak flavor, and even that is up for debate – Montana labels theirs with a sell-by date that’s 12 days post-pasteurization while Washington requires a use-by date 21 days after pasteurization takes place.

Pasteurization is the process that mills most harmful bacteria, and if consumers keep the milk refrigerated and out of direct sunlight, keep the carton closed and stored on a shelf in your fridge (the temperatures in the door compartments fluctuates more), the bacteria shouldn’t creep back in for a certain number of days.

The rule of thumb for whole milk is to drink it within 5 days of the “sell-by” date. Skim and reduced-fat milk go bitter a bit quicker, and your ultra-filtered milk will last a bit longer, so you’ll be okay using a sniff test with those.

If you’re immunocompromised or otherwise in poor health, you will always want to err on the side of caution.

If you’re young and healthy, even drinking spoiled milk won’t kill you, so there’s that.