Cellars are a kind of storage which has the ability to make the food stored in it last longer. Building a cellar is highly recommended, because it can nearly double how long food can last. To build a cellar you need:

Building a cellar takes 3 hours. To store something in the cellar, just drop the item on top of it. Always build cellars outside, as building them on a floor/ceiling tile will destroy the floor and ceiling. A cellar tile is actually considered to be "outside", as you can see the raindrop when it's raining, and it is noticeably colder than "indoor" tiles. You can freeze to death when standing on a cellar, even though the fireplace is right next to you.

Since the food can be stored past their 'expiration date', only take food out to eat. A roasted meat cut might rot in the time you take from your cellar to the nearest village just because you left it too long in cellars.

Raw meat and fish will stay fresh for 3 days without being cooked. All raw and cooked food will last longer if kept in a cellar

Roasted - Stays fresh for 6 days. Roasted meat takes less than an hour to be ready.

Smoked - Stays fresh for 40 days. Smoked meat takes 16 days to be ready, smoked fish takes 20.

Salted - Stays fresh for ~40 days. Salted meat takes 3 days to be ready, salted fish takes 5.

Dried - Stays fresh for 120 days. Dried meat takes 24 days to be ready, dried fish takes 20.

Maintain different cellars so you could differ this year's food and last year's food. Besides, it's gratifying to see several cellars full of food, right?