To Freeze or Not to Freeze and Related Questions

Your freezer is a staunch ally in the fight against food spoilage and waste. But to get the most shelf life out of the products you freeze and to avoid spoiling products that don’t react well to the freeze/defrost process, you need some know-how.  The following FAQs, answered by our Advisory Board scientists and other reliable sources, will give you a lot of the info you may need.

Q. Some people say that anything but lettuce can be frozen.  Is that true?

A. You can freeze anything.  No freezer policeman is guarding the door.  The question is this: how will it taste or look when defrosted (and perhaps reheated)? The list of items for which freezing is not recommended is rather long.  Food scientist Dr. Catherine Cutter got us started by mentioning lettuce, sour cream, and some other cream sauces.  If you do freeze sour cream or cream sauces, when defrosted, they may be usable for cooking but not for company.

Food process engineer Dr. Tim Bowser has a longer list.  Here goes: “Many fruits turn mushy when frozen, but that can be considered an advantage for making certain recipes, like smoothies. Cooked pasta tends to get soft after thawing. Potatoes may turn grainy. Vegetables with high water content (like lettuce) become very limp and unpalatable for most uses. Fried foods become unpalatable because of oil separation. Soft cheeses and yogurt (which have a high moisture content) separate. Glazes and some frostings with high moisture content can become separated and result in soggy products. I have heard reports that the flavor of many spices and seasonings change as a result of freezing, but issues in this category should be considered on a case-by-case basis. Mayonnaise may break down when it’s been frozen.”  

Consumer Reports on Health adds a few more we haven’t mentioned so far: cooked rice, fresh tomatoes, shelled eggs, mushrooms, and whole potatoes. The publication also suggests that, to avoid mushiness, whole berries should be puréed before freezing. 

Q. What’s the best time to freeze foods?

A. Consumer Reports on Health advises the following:

   - Freeze foods at their freshest rather than when they’re well on the road toward becoming spoiled.

   - Fish, meat, seafood, and poultry freeze better raw than after they’re cooked.

Q. How can I get food to freeze quickly?

A. Do not stack one item on top of another until each one is frozen solid.  Refrigerate before freezing.  Divide large portions into smaller ones since smaller portions freeze faster, and put the unfrozen packages in different areas of the freezer if possible.

Q. Is there an advantage to freezing foods quickly?  If so, is it a good idea to divide foods into small portions for freezing?

A. The more slowly food is frozen, the larger the ice crystals.  Large ice crystals cause more cells to rupture and lose fluid when defrosted, and the result is less tasty food. However, home freezers are not cold enough to allow consumers to freeze foods extremely quickly. Therefore, cutting meat or cake into small pieces to speed up the freezing process is probably not going to accomplish much, says Dr. Cutter.  “A whole roast has less surface area than a roast cut into steaks, and that means the steaks will have more ice crystals and more moisture will be pulled out of the food.” 

According to Dr. Cutter, “The food industry uses IQF (instant quick freeze) systems to freeze products VERY quickly and maintain food integrity.” 

Q. Is it safe to defrost and eat food that’s been frozen for a year or more?

A. Safe?  Yes.  Enjoyable? Maybe not.  Pathogens cannot grow in frozen food because it’s too cold.  Therefore, if the food was safe to eat when you put it into the freezer, it will be safe when defrosted and consumed, assuming proper handling and cooking. (But if the food was unsafe to eat before freezing, the freezer may not kill the harmful organisms.) What we’re talking about here is not safety but palatability and appeal.  How will it taste and look?  Will the ingredients separate?  Will the texture be retained, or will once-firm foods have turned to mush? 

How long frozen food will last depends mostly upon the nature of the food and the protective quality of the wrapping.  To find out how long a particular product will retain high quality in the freezer, check the charts on this site by putting the product name and the words “shelf life” into the “search” box on the home page.  Wrap it well, and there’s a good chance you’ll enjoy eating your wedding cake on your first anniversary. 

Q. How should food be wrapped for freezing? 

A. Here’s the usual one-word answer: tightly. That’s important to keep out oxygen that can cause food to become rancid and lose moisture. The result would be freezer burn, which creates dried-out, poor-quality food. However, there is an exception to this general advice about wrapping tightly:  moist foods and liquids need a little empty space to allow for the expansion of the liquid when it’s frozen. (Ice takes up more room than the same amount of water.)

Food scientist Dr. Joe Regenstein recommends wrapping in freezer plastics rather than aluminum foil because aluminum foil degenerates over time and allows air to reach the food. “Foil is not perfectly air-tight from the beginning as it may have some pinholes. Also, using it to wrap tightly around many foods may lead to tears in foil.”

For this site’s detailed suggestions on the best ways to wrap different kinds of foods for freezing, click here: http://shelflifeadvice.com/tips/how-wrap-foods-freezer 

This link will get you to info on wrapping for both refrigeration and freezing: http://shelflifeadvice.com/content/how-should-food-be-handled-and-wrapped-freezing .

Q. After serving raw veggies and dip, I usually have a lot of leftovers.  What’s the best way to freeze raw veggies?

A. Forget about saving them for your next raw veggie ‘n dip tray.  Blanche (partially cook) them before freezing, and later use them as a cooked side dish.

Q. I’m leaving town on vacation.  Do I have to toss a bunch of bananas, or can I freeze them and use them when I get back?

A. Food process engineer Dr. Tim Bowser recommends peeling, wrapping tightly, and freezing. When you defrost the bananas, you’ll have mush—perfect for making smoothies.

Q.  Is storing food in the freezer door as effective as storing in the freezer compartment?

A.  No. An article from Eating Well Magazine gives this explanation and advice:  “The temperature near and on the door fluctuates every time the door is opened.  Although the food may remain frozen, the freezing process could be slowed, opening up the possibility for larger ice crystals to form inside the food and destroy its integrity.”

It’s a good idea to put frozen foods you plan to use soon near the front and those you want to leave in the freezer for longer in the back, where the temperature will remain constant.

Personal experience has taught me that a loaf of bread is an especially bad item to put in the freezer door.  It gets dried out and stale quickly there.

In general, says Dr. Regenstein, avoid opening and closing the freezer often.  Even small fluctuations in temperature will accelerate the formation of larger, more damaging, ice crystals.

Q. Can I freeze egg yolks left over after using the whites for baking?

A. It can be done.   What’s Cooking America has  all the info on how to do it.  One of the tricks is to add salt and stir gently. However, if you’re going to use the yolk(s) within 3 days, you don’t need to freeze them; refrigeration is adequate. 

Q. Can I freeze croutons, breadcrumbs, grated cheese, and fresh herbs to have them ready to use when I’m in a hurry and not going to the store?

A. Yes, says a Reader’s Digest article.  It has tips on exactly how to freeze these items.  Click here to reach this article: http://www.rd.com/slideshows/8-foods-to-store-in-the-freezer-for-quick-meals/8/   But don’t be surprised if you have some quality issues with the defrosted product.

Q. Any tips on what and how to cook for parties by freezing and cooking or reheating later? 

A.  Consumer Reports on Health recommends the following book: Cook and Freeze: 150 Delicious Dishes to Serve Now and Later by Dana Jacobi (Rodale, 2010).

Q. What are the best ways to defrost frozen items?

A. There are three ways: in the fridge, in cold water, or in the microwave (on the defrost setting.  For details on the best way to use each method, click here: http://shelflifeadvice.com/tips/how-defrost-frozen-foods  Never leave foods at room temperature on the counter.   The surfaces may become warm enough for spoilage or pathogenic bacteria to grow.

Q. Can I refreeze food that’s been defrosted?

A. Yes.  It’s safe to do so if it has been defrosted in the refrigerator.  However, the additional freezing step may lead to further deterioration of quality.

Dr. Regenstein makes this point about American freezers: “It is important to note that the home freezer is misnamed. It is meant for keeping already frozen products frozen.  It is not meant to take products that are not frozen and give you a high-quality frozen product.  In some countries, the freezer would be called a cold storage and a real freezer would be much colder and have fast-moving air to actually freeze a product.”

Sources (in addition to links within the article):

Timothy J. Bowser, Ph.D.  Oklahoma State University, Dept. of Biosystems and Agricultural Engineering

Catherine N. Cutter, Ph.D., Pennsylvania State University, Dept. of Food Science

Joe Regenstein, Ph.D., Cornell University, Dept. of Food Science

eatingwell.com “6 myths about freezing food”

http://www.eatingwell.com/blogs/healthy_cooking_blog/6_myths_about_freezing_food

Consumer Reports on Health November 2011.