Refrigeration Tips: Keeping Vegetables Fresh
If you're like most people, you unpack your groceries and plunk your vegetables into the refrigerator without a second thought. Did you ever wonder why your lettuce turns brown, your carrots go limp, and your tomatoes taste like cardboard? Learn how to use your refrigerator more efficiently - and which vegetables shouldn't be refrigerated at all - to keep your vegetables at their peak of flavour.
Vegetables like storage conditions that range from cold and moist to warm and dry. Factors to consider in storing vegetables include:
- What's the optimal temperature?
- How much humidity is best?
- Which vegetables absorb or release odours?
- Which vegetables absorb or release ethylene?
Get to Know Your RefrigeratorThe temperature in your refrigerator should be 34°- 40°F (1°-4°C). Pathogenic (disease-carrying) bacteria thrive above 40°F. Below 40°F, spoilage bacteria can still grow on foods - affecting their taste and smell - but they're not generally harmful. If the temperature is too low, vegetables can freeze.
Most refrigerators have special compartments or "crisper drawers" to store fruits and vegetables, often with slide mechanisms to control the humidity in the drawer. An open setting lets out moist air - good for vegetables that like it drier such as onions, garlic, and winter squash. A closed setting keeps moist air in - good for vegetables that like high humidity such as leafy greens, non-leafy brassicas, cucumbers, root vegetables, celery, collards, kohlrabi, leeks, summer squash, and peppers.
With more than one crisper drawer, you can group vegetables by their temperature and humidity needs. Crisper drawers are most effective when they're at least two-thirds full.
One tip: a combination thermometer/humidity gauge is useful to check temperature and humidity in different parts of the refrigerator. It's especially useful in case of a power outage. If the temperature stays below 40°F (4°C), food is safe to eat; if it goes above 40°F for over two hours, food should be discarded.
Sensitivity to EthyleneMany vegetables are sensitive to ethylene, a chemical emitted by many fruits and some vegetables.
Foods that emit ethylene include: apples, avocados, bananas, pears, peaches, plums, cantaloupes, honey dew melons, mushrooms, and tomatoes.
Vegetables that absorb ethylene include: brassicas, leafy greens, beans, carrots, cucumbers, eggplant, peas, peppers, and potatoes.
Some effects of ethylene exposure are:
- Pitting and "russeting" (brown spots) on string beans and lettuce
- Yellowing of broccoli buds, cucumbers, and Brussels sprouts
- Bitterness in carrots
Odour AbsorptionSome fruits and vegetables emit odours that can affect the taste of other foods. A box of baking soda in the fridge absorbs both odours and moisture. Remove the top layer of soda periodically to maintain its effectiveness.
Some Interactions Include:
- Apples produce odours absorbed by cabbage, carrots, and onions.
- Pears produce odours absorbed by cabbage, celery, carrots, onions, and potatoes.
- Onions and scallions produce odours absorbed by apples, celery, corn, grapes, leafy greens, mushrooms, pears, and rhubarb.
Bag ItSome vegetables lose moisture quickly and should be stored in plastic bags, containers, or wrap (or paper bags). Perforated plastic or paper bags are best. Vegetables that should be bagged include: beans, broccoli, cabbage, carrots, cauliflower, cucumbers, kohlrabi, lettuce, leafy greens, radishes, scallions, and turnips.
General Storage Tips
- Don't wash vegetables before refrigerating - wash before eating. Too much moisture is detrimental and can cause lettuce to turn brown, for example.
- Remove tops on beets, carrots, parsnips, and radishes before storing
- Keep ethylene-emitting and odour-emitting foods bagged.
- Tomatoes or any vegetable picked to ripen after harvest shouldn't be refrigerated.
How Long Will They Keep?General rules for how long vegetables will keep in the refrigerator:
- 2-3 Days: asparagus, corn (unhusked)
- 3-5 Days: broccoli, Brussels sprouts, lima beans, peas, scallions
- One Week: beans, cauliflower, cucumbers, leafy greens, leeks, lettuce, peppers, scallions, summer squash
- One to Two Weeks: celery
- Two Weeks: beets, carrots, parsnips, radishes, turnips
- Three Weeks: parsnips and rutabagas
Tips by VegetableAubergine: Refrigerator temperatures are too low for aubergine, which prefers 50°-60°F (4°-10°C) with high humidity. Storing in a paper bag in the crisper drawer is the best compromise. Aubergine absorbs odours from ginger roots, so don't store them together. Aubergine will only stay fresh about ten days.
Onions - Cut onions will keep refrigerated for up to three days if tightly wrapped.
Potatoes and Winter Squash: Potatoes are best not stored in the refrigerator. See "Vegetable Drying and Cold Storage" for advice on storing potatoes and winter squash.
Tomatoes: Tomatoes keep best at about 60°F (16°C) and lose flavour if refrigerated. Store on the counter out of sunlight. See "Vegetable Drying and Cold Storage" for other tomato storage tips.
Turnip Greens: Turnip greens don't store well; use promptly. Store in a plastic bag to contain their strong odour.