[removed]

They don’t really know, thats why some food spoils faster than the date. They just know how long the food has until its freshness or “perfect flavor” is left until its not in a sellable quality

The "best before" date is actualy a "tastes optimal if opened before". It's a guestimate, based on experiments. It has nothing to do with food spoiling, so they can afford to approximate.

Usually, there are some tests before launching some new product line with different sealed containers sitting there for different amounts of time at room temperature or fridges. For dates a year or more away, they guess using science. Petri dish cultures, for example, can help them extrapolate future dates just by watching the bacteria growth rate.

A relative of mine used to work in the field of frozen food. They conducted a "crash test": If you defrost and re-freeze food several times, this mimics "decay" in a quicker way. From those results, they could figure out shelf life (without actually having to wait e.g. 27 months).

Aha, I was wondering if there was a way they could imitate decay!

I can imagine it would be much more risky from a liability standpoint to have a spoilage-based date on foods.

It is completely unregulated except for infant food and formula. That said, companies tend to err on the side of caution as it’s better for business for customers to throw out products that might still be edible as opposed to facing lawsuits over spoiled food.

Interesting! Didn't know there was no regulation around it.

On the flip side, there's heated chambers that do the same thing. There are some companies that will legit evaluate their product every week/month during development until is no longer meets quality or safety specs.

Cool! Still wonder how they've worked that out!

That's half the reason. The other reason is for marketing purposes. This way, you guarantee taste, not edibility. You get less complaints that your stuff doesn't taste good, as people know they're past the "best before" date.