Some foods, like milk and eggs, belong in the fridge. But beyond the standard perishable items, there are several packaged foods and produce that benefit from storing under cooler temps. We get that fridge real estate is precious, but to reap the benefits (and flavour) from some of your go-to staples, create some chilling space for these essentials.

10 Foods To Refrigerate After Opening

1. Nuts and Seeds

Mixed nuts and seeds in a bowl

Photo, Erik Putz.

Nuts, nut flours and seeds are high in unsaturated fatty acids that grow rancid with exposure to warm temperatures over time. To maintain flavour keep items like almonds, flax seeds or cashews in a well-sealed plastic or glass container in the fridge for up to six months. Out of fridge space? Store nuts and seeds in the freezer to keep them fresh for up to a year.

2. Maple Syrup

Maple syrup can

Photo, Erik putz.

Unlike corn syrup-based substitutes, natural maple syrup does not contain any preservatives, and can spoil very quickly once you’ve opened it. (Unopened, it can last two to four years, depending on if it’s in plastic or glass packaging.) Don’t waste any of that liquid gold—refrigerate maple syrup right after opening, and it will keep for several months (and your Saturday pancake stack will thank you for it).

3. Whole Grain Flour

measuring out flour - perfect baking. Image, Roberto Caruso.

White flour can last in the pantry much longer than whole wheat flour—up to two years. Photo, Roberto Caruso.

Whole wheat flour contains wheat bran and germ, which are rich in nutrients and oils. This makes it more appealing to pests and prone to spoiling. While white flour will last in the pantry for up to two years, whole-grain flours will go rancid after about three months. Storing whole grain flours like whole wheat, spelt and rye, in the fridge or freezer will extend their shelf life and protect them from pest infestation.

4. Natural Peanut Butter

Natural peanut butter in a bowl

Photo, Roberto Caruso.

A life hack for never having to stir your natural nut butters again: Place the jar upside down in your fridge immediately after unpacking your groceries. This brings up the solid pieces from the bottom and helps emulsify them with the oil, so you won’t end up with weird chunks towards the bottom of the jar. Plus, the cool temperature prevents it from becoming rancid and makes the nut butter less fluid, helping avoid over-the-jar oil spills.

5. Soy Sauce

Kikkoman soy sauce

Kikkoman Soy Sauce.

Soy sauce’s high sodium content will keep it from spoiling at room temperature, but it loses freshness as it ages, and the flavour will eventually lose its strength. Once opened, refrigerate to preserve optimal freshness.

6. Fresh Corn

Cobs of fresh corn in husks

Photo, Sian Richards

To maintain the beautiful flavour of sweet, seasonal corn on the cob, immediately refrigerate what you aren’t planning to cook right away. An ear of corn can lose up to 50 percent of its sugar content within one day of being harvested, so be sure to store it (husk-on) in the fridge for up to two days after purchasing. The cool temperature will keep the sugars from turning to starch, preserving its delicious and sweet flavour.

7. Ketchup

Homemade Ketchup it tall glass bottle

Photo, Erik Putz.

Ketchup’s high acidity and salt content will keep bacterial growth at bay at room temperature, but every time the bottle is opened it’s exposed to bacteria and mold in the air, and it may start to separate and turn brown. For this reason, Heinz suggests keeping opened bottles in the fridge.

8. Tortillas

Roasted cauliflower tacos

Photo, Sian Richards.

Soft corn or flour tortillas, especially those made without added preservatives, can get moldy quickly when left out on the countertop. The accelerated moisture loss that occurs at fridge temperatures prevents the growth of mold, so tortillas are less likely to spoil before the package is finished.

9. Citrus Fruits

Sliced citrus fruit

Photo, Erik Putz.

Oranges, lemons and limes can be left out on the counter, but keeping citrus in the fridge will save them from drying out for up to one month. Clear out room in that crisper, ASAP.

10. Red Wine

overly full red wine glass with wine spilling out

Photo, Roberto Caruso.

Didn’t make it through the whole bottle of cabernet? Stick your red wine in the fridge after opening. By limiting the wine’s exposure to light, oxygen and heat, you will slow down the chemical reactions that make multiple-days-old wines taste lousy. Just make sure to remove the wine from the fridge about an hour before drinking.