A fridge is where food goes to be forgotten. Half a bunch of cilantro liquefying in the drawer, a container of something from a week and a half ago that nobody will open, three jars of the same mustard. None of that is a failure of willpower. It is mostly a failure of placement, because things stored where you cannot see them are things you will not eat.
The cold end of a kitchen has two jobs. It has to keep food out of the temperature range where bacteria multiply quickly, which is the part with actual rules attached. And it has to keep food in usable condition long enough for you to get around to it, which is the part that decides how much money goes into the bin. They are different problems and they want different habits.
Set the temperature, then verify it
A refrigerator should hold at or below 40°F, which is 4°C. A freezer should hold at or below 0°F, or -18°C. The dial inside most fridges is numbered one through five and tells you nothing about either. An appliance thermometer costs less than a bag of coffee, sits on a middle shelf, and is the only way to know whether the setting you inherited from the previous tenant is doing anything.
The range between roughly 40°F and 140°F is where bacteria grow fastest. Almost every storage rule below is a way of describing how long a given food is allowed to spend in that band.
The fridge has zones, and they differ by several degrees
Cold air sinks and the door swings open into a warm kitchen several times a day, so the shelf on the door is the warmest real estate in the appliance and the back of the bottom shelf is the coldest. That is worth knowing because most fridges come with a molded egg holder in the door, which is precisely the wrong place for eggs and for milk.
| Door | Condiments, pickles, anything acidic and shelf-stable in spirit. Not milk, not eggs. |
|---|---|
| Top shelf | Leftovers and anything ready to eat, up where you will see it. |
| Middle shelf | Dairy and eggs, which want steady cold rather than the door's swings. |
| Bottom shelf | Raw meat, poultry, and fish, in a tray or a bag, below everything else so nothing drips down onto food that will not be cooked. |
| Crisper drawers | Produce, sorted by whether it needs humidity or resents it. |
The crisper drawers are not just drawers
The slider on the front of each drawer opens or closes a vent. Closed keeps humidity in, which is what leafy greens, herbs, carrots, and broccoli want. Open lets moisture and ethylene gas escape, which is what most fruit wants. Ethylene is the ripening signal a lot of fruit gives off, and it will happily ripen the vegetables sitting next to it into softness.
- Heavy ethylene producers: apples, pears, stone fruit, avocados, bananas, tomatoes, melons.
- Notably sensitive to it: leafy greens, broccoli, cucumbers, carrots, asparagus, herbs.
- The practical version: keep the fruit drawer vented and away from the greens drawer, and do not store apples on top of the salad.
Things that get worse in the cold
- Tomatoes, which lose aroma and turn mealy below about 55°F. Counter, stem side down.
- Potatoes, where cold converts starch to sugar and gives them a sweet, oddly dark fry. Cool, dark, ventilated, away from onions.
- Onions and garlic, which want dry air and go soft in a humid drawer.
- Whole winter squash, which keeps for months on a shelf and rots faster cold.
- Bread, which goes stale fastest at refrigerator temperatures. Keep two days out, freeze the rest.
- Basil, which blackens in the cold. Treat it like a cut flower in a glass of water on the counter.
The clock that actually matters
Perishable food should not sit at room temperature for more than two hours in total, and not more than one hour if the room is above 90°F. That total is cumulative across the day: the hour it spent on the counter while cooling counts against the hour it spends out at the table later.
Which means the instinct to let a pot cool fully before it goes in the fridge is backwards. Divide it into shallow containers so it loses heat quickly and refrigerate it while it is still warm. A stockpot cooling on the stove holds its heat in the middle for hours, and that middle is sitting in the danger band the whole time. Modern refrigerators handle the warm container without trouble.
Cooked leftovers keep three to four days in the fridge. Reheat them all the way through to 165°F, not merely to warm, and bring soups and sauces to a rolling boil. Write the date on the lid with a marker, because the entire failure mode here is the container nobody can date by looking at it.
The freezer is the anti-waste appliance
Food held at 0°F stays safe indefinitely. Quality is a different matter, and it degrades through dehydration at the surface, which is what freezer burn is: not dangerous, just dry and dull. Pressing air out of the bag and freezing things flat solves most of it, and a flat package also thaws in a fraction of the time.
- Herbs about to turn, chopped into an ice cube tray with oil or water.
- The last third of a can of tomato paste, in tablespoon dollops on a sheet pan.
- Bread, sliced first so you can take what you want.
- Stock, in the portion size you actually use rather than one enormous block.
- Bananas going brown, peeled, for baking or for smoothies.
Thaw in the refrigerator, in a sealed bag under cold running or frequently changed water, or in the microwave if you are cooking it immediately. Not on the counter, where the outside spends hours in the warm band while the center is still ice. Anything thawed in the fridge and still cold can be refrozen, at some cost to texture.
Two things people get wrong about dates
Best-by and sell-by dates are manufacturer estimates of peak quality, not safety deadlines, and in the United States infant formula is the only product whose date is federally regulated. Yogurt a week past its date is a judgment call you can make with your nose. Use-by on a package of ground meat is worth taking more seriously.
And if the power goes out, keep the doors shut. An unopened refrigerator holds food safely for about four hours. A full freezer holds for roughly two days, a half-full one for about a day. Every time someone opens the door to check, that clock gets shorter.