By Dr. Mercola
Whether or not thawed, if previously frozen foods can be refrozen is one of the most popular questions posed to the US Department of Agriculture's (USDA) Food Safety and Inspection Service (FSIS) food-safety hotline.
It's also one of the most widely circulated myths that refreezing food is dangerous.
While putting a thawed piece of steak or brick of cheese back into the freezer might lead to some changes in taste or texture, it's perfectly safe and poses no risks to your health. There are a few caveats to consider, however.
It's Safe to Refreeze Thawed Food
Thawed food can be safely returned to your freezer provided it was thawed safely in the first place. The worst way to thaw frozen food is to let it sit out on your kitchen counter. Tina Hanes, a registered dietitian with the USDA's FSIS, told The New York Times:1
"… [B]acteria like it warm, like we do, and multiply rapidly at room temperature. Thawing on the counter is not safe, period. You should never do that."
In fact, it's said the greatest factor impacting whether your food is "safe" isn't whether it's been previously frozen but rather is related to how much time it spends in the temperature "danger zone" (between 40 to 120 degrees F).2
In addition to thawing on the counter, thawing frozen meat, poultry, or seafood by running warm water over it is also risky from a food-safety standpoint. If you need to thaw meat or poultry quickly, it can be run with cold water over it, or submersed in cold water, changing the water every 30 minutes until it's thawed.3
If you use this latter method for thawing, it should be cooked immediately – not refrozen or put back in the fridge. The USDA further advises:4
"Once food is thawed in the refrigerator, it is safe to refreeze it without cooking, although there may be a loss of quality due to the moisture lost through thawing. After cooking raw foods which were previously frozen, it is safe to freeze the cooked foods.
If previously cooked foods are thawed in the refrigerator, you may refreeze the unused portion. Freeze leftovers within 3 to 4 days. Do not refreeze any foods left outside the refrigerator longer than 2 hours; 1 hour in temperatures above 90 °F.
If you purchase previously frozen meat, poultry or fish at a retail store, you can refreeze if it has been handled properly."
Do Frozen Foods Retain Their Nutrients?
It's generally best to consume foods fresh, as soon after harvest as possible. However, frozen foods aren't a bad alternative when this isn't possible. In some ways, frozen foods may even be "fresher" than foods at your supermarket.
This is because produce is typically frozen soon after harvest, whereas fresh produce may be shipped thousands of miles before it actually reaches your local store (with nutrients degrading the entire way).
Research suggests fresh vegetables may lose up to 45 percent of their nutrients from the time they're harvested to the time they're purchased at a grocery store.5 On the other hand, research suggests frozen foods may contain comparable nutrients as fresh foods, and at times be even more nutritious. For instance:6
- Frozen broccoli had more vitamin C, lutein, and beta-carotene but lower levels of polyphenols (some frozen broccoli has also been found to lack the ability to produce cancer-fighting sulforaphane7)
- Frozen carrots had three times more lutein and twice as much beta-carotene, as well as more vitamin C and polyphenols
- Frozen sprouts had higher levels of all measured nutrients
- Frozen blueberries, green beans, raspberries, and pears also had higher levels of vitamin C and polyphenols
Separate research on frozen versus fresh carrots, broccoli, spinach, strawberries, and more concluded "overall, the vitamin content of the frozen commodities was comparable to and occasionally higher than that of their fresh counterparts."8
The exception in this case was beta-carotene, which declined significantly in some of the frozen produce.
There's still no question that the most nutrient-rich food will be fresh, provided you can eat in within a short time from harvest (i.e. produce you either grow yourself or purchase from a local farm or farmer's market). However, frozen foods are still fairly nutritious and worthy of consumption if locally grown fresh foods are not available.
Freezing Your Food Can Help Cut Down on Food Waste
The other benefit to freezing your food (or re-freezing it) is cutting down on food waste. Organic waste, such as that from spoiled food, is actually the second highest component of landfills in the US. Organic landfill waste has increased by 50 percent per capita since 1974.9
A report from the National Resources Defense Council (NRDC) revealed that 40 percent of food in the US goes uneaten, which amounts to a waste of more than 20 pounds of food per person, every month. This amounts to upwards of $2,275 in annual losses for the average US household of four.10 This isn't simply a matter of the food itself, as with this waste comes:
- $165 billion that is essentially "thrown out"
- 25 percent of freshwater usage, wasted
- Huge amounts of unnecessary chemicals, energy, and land use, also wasted
- Rotting food in landfills, which accounts for nearly 25 percent of US methane emissions
The NRDC report also estimates:11
"… [F]ood saved by reducing losses by just 15 percent could feed more than 25 million Americans every year at a time when one in six Americans lack a secure supply of food to their tables."
In all, it's estimated US families throw out about 25 percent of the food and beverages they buy. In the UK, about two-thirds of household food waste is due to food spoiling before it is used. And shockingly, more fruits and vegetables are wasted in the US food system than are actually consumed (52 percent are wasted versus 48 percent consumed)!12
So if you find you've brought home more perishable food than you can consume, wrap it up tight and put it in your freezer (with the exception of the foods that follow… ).
Certain Foods Do Not Freeze Well
Most foods can be frozen successfully, provide you store them correctly in your freezer. However, freezing does alter or degrade the quality of some items. Spices and seasonings are particularly vulnerable.
Foods Usual Use Condition After Thawing Cabbage,* celery, cress, cucumbers,* endive, lettuce, parsley, and radishes As raw salad Limp, water-logged, quickly develops oxidized color, aroma, and flavor Irish potatoes, baked or boiled In soups, salads, sauces, or with butter Soft, crumbly, water-logged, and mealy Cooked macaroni, spaghetti, or rice When frozen alone for later use Mushy, tastes warmed over Egg whites, cooked In salads, creamed foods, sandwiches, sauces, gravy, or desserts Soft, tough, rubbery, and spongy Meringue In desserts Soft, tough, rubbery, and spongy Icings made from egg whites Cakes, cookies Frothy, weeps Cream or custard fillings Pies, baked goods Separates, watery, and lumpy Milk sauces For casseroles or gravies May curdle or separate Sour cream As topping, in salads Separates, watery Cheese or crumb toppings On casseroles Soggy Mayonnaise or salad dressing On sandwiches (not in salads) Separates Gelatin In salads or desserts Weeps Fruit jelly Sandwiches May soak bread Fried foods All except French fried potatoes and onion rings Lose crispness, become soggy *Cucumbers and cabbage can be frozen as marinated products such as "freezer slaw" or "freezer pickles." These do not have the same texture as regular slaw or pickles.
According to the National Center for Home Food Preservation, some herbs, such as onion and paprika, change flavor when frozen, while others tend to get stronger (this applies to pepper, cloves, garlic, and green pepper).
Frozen curry may develop a "musty off-flavor," while salt may lose its flavor and even increase rancidity of foods containing fat. If you know a food will be going in the freezer (such as a big batch of tomato sauce), your best bet is to season it lightly prior to freezing and then add your finishing touches after it's been thawed and re-heated.13 The National Center for Home Food Preservation has also posted this useful chart of foods that generally do not freeze well:14
How to Best Freeze 5 Common Foods
By taking a few moments to properly wrap and prepare your food for the freezer, you can extend its freezer shelf life and ensure a higher-quality product once thawed. The National Center for Home Food Preservation has a comprehensive guide on how to best freeze common foods.15 Examples are as follows:16
- Butter: Mold into the shape of your choice (squares, patties, etc.), wrap tightly in aluminum foil or freezer paper, and then seal in moisture-vapor resistant containers. Recommended freezer storage time is six to nine months.
- Cheese: Hard or semi-hard cheese should be cut into 1.5 to one-pound sizes the packaged in moisture-vapor resistant material. It may be crumbly and mealy when thawed but will still be flavorful. Cream cheese, cottage cheese, and ricotta cheese generally do not freeze well.
- Blueberries: Do not wash blueberries. Pack them dry into containers, leaving headspace; this allows the food to expand without breaking the packaging. You can also freeze them flat on a tray then pack them into containers once frozen.
- Meat (beef, lamp, and pork): Package the meat in freezer paper or wrap. Store-bought meats should be over-wrapped with freezer paper (unless it is wrapped in a newer heavy-duty film, which needs no overwrap).
- Tomatoes: Wash the tomatoes and dip them in boiling water for 30 seconds to loosen skins. Peel and core the tomatoes, then pack into containers, using one-inch headspace (the tomatoes can be frozen whole or in pieces). Once thawed, the tomatoes will no longer be solid so plan to use them in cooking.
More Freezer Pointers
If you're wondering how long food will keep in your freezer, it's not forever. Fruits and vegetables will last longest, about eight to 12 months, while ground meat maintains its quality for about three or four months. Fish ranges from three to six months while poultry will keep for six to nine months.
Keep in mind that food will still be safe to consume after these storage times, but it may not be as high in quality (i.e. its texture or flavor may change). Additional pointers to help you successfully store food in the freezer include the following from The National Center for Home Food Preservation:17
- Freeze foods at 0°F or lower. To facilitate more rapid freezing, set the temperature control at -10°F or lower about 24 hours in advance.
- Freeze foods as soon as they are packed and sealed.
- Do not overload your freezer with unfrozen food. Add only the amount that will freeze within 24 hours, which is usually 2 to 3 pounds of food per cubic foot of storage space. Overloading slows down the freezing rate, and foods that freeze too slowly may lose quality.
- Place packages in contact with refrigerated surfaces in the coldest part of the freezer.
- Leave a little space between packages so air can circulate freely. Then, when the food is frozen, store the packages close together.