Winter Food Storage—Can I leave It in the Car or in the Garage?

Summer heat is riskier than winter chill in terms of food contamination, but  winter presents its own challenges for food spoilage or pathogen growth.  Let’s consider some typical winter situations involving food storage.

Q. Let’s suppose…I’m on my way to a pot luck dinner, and I’m bringing the beverages.  Can I leave them in the car for a few hours while I have lunch with a friend and tour a museum? 

A. That depends upon 2 factors: how cold is it, and what kinds of beverages are you packing?  Let’s assume you don’t want your beverages to freeze (and perhaps explode).  Here’s some information (thank you, Answers.com) that might provide you with some guidance:

• Water and diet soda freeze at 32°F.  Regular sodas (with sugar) freeze at about 30°F.

About.com provides this useful information on alcoholic beverages:  The exact freezing point of alcoholic beverages is dependent on its proof (amount of alcohol per volume).  The lower the proof, the warmer the freezing point and vice-versa.  Here are the examples the site gives:

24 proof liquor freezes at 20°F (-6.7°C)

64 proof liquor freezes at -10°F  (-23.33°C)

84 proof liquor freezes at -30°F  (-34.44°C)

Keep in mind that the temperature inside the car will be slightly warmer than the outdoor temperature (due to insulation).  For example, if the outdoor temperature is 30°F, the interior may be around 40°F. The trunk will be cooler than the inside of the car. 

Lower proof alcoholic beverages, if left in a very cold car (or a freezer) for hours could get slushy, eventually freeze, and even explode, leaving you with a big mess.

Q. Let’s suppose…I’m attending the same potluck dinner and am bringing tuna salad and egg salad sandwiches dressed up with lettuce.  Can I leave them in the trunk of my car for several hours?

A. Better check the temperature of your trunk as well as the weather forecast for the day.  These foods should be kept at about 35 - 40°F.  If the temperature is likely to go down a lot below that, your food may freeze.  Eggs, lettuce, and mayonnaise don’t freeze well. Defrosted food won’t make the diners sick, but it won’t taste great.  (Who likes wilted lettuce?). 

On the other hand, if the temperature is above 40°F, the food will be in the “danger zone,” the temperature range in which bacteria grow quickly.  If your car doesn’t feel like a refrigerator, don’t expect it to function as one.  Borrow or buy an insulated cooler and add some cold packs along with the food.

Q.  Let’s suppose…I’ve been out to dinner and  have taken delicious leftovers with me for lunch tomorrow.  But now we’re going to a movie and won’t get home for at least another 3 hours. If I leave my leftover dinner in the car or trunk, will it be safe to eat tomorrow?

A.  Perishable food should not be at room temperature for more than 2 hours. After that period, pathogens grow rapidly.   Is the interior of your car 40°F or below?  If not, there’s a risk of food-borne illness. Keep in mind that the restaurant food will probably be warm when you put it into the car, and your car will be warmed by the heater until you get to your second destination. Also, a temperature that may feel chilly to you could actually be above 40°F and in the “danger zone.”  If you put your dinner in the trunk, it will stay a little cooler.

In some communities, drivers actually leave their leftover dinners on top of the car for maximum cooling, but do that and you might wind up unintentionally providing an evening snack for a homeless person or animal). 

Q. Let’s suppose…The party is at my house, and I’ve run out of refrigerator space.  Can I move my raw veggies to the garage overnight?

A. What veggies are you thinking of banishing to the garage?  Carrots can tolerate cold weather well, but onions and potatoes will be ruined if the temperature gets below 32°F.   However, the good news is that onions, potatoes, and squash will be happy at around 50°F, so if winters are mild in your neck of the woods, you can leave them in the garage.  But here’s another thought:  raw potatoes can also be left hanging in the kitchen at room temperature. If they’re in a wire basket and exposed to a lot of air circulation, they’ll survive for weeks. 

Before storing food in a garage, you can take a thermometer out there and see how cold it actually is and where the hot spots and cold spots are.  The garage temperature is affected by the exposure (north, south, etc.) and the amount of insulation.  Your garage may be warmer (or colder) than you realize.

Source(s):

Karin E. Allen, Ph.D., Utah State University, Dept. of Nutrition, Dietetics, and Food Sciences

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

About.com “Will Liquor Freeze?”

http://cocktails.about.com/od/mixology/f/alcohol_freeze.htm

Answers.com “What is the freezing temperature of soda pop?”

http://wiki.answers.com/Q/What_is_the_freezing_temperature_of_soda_pop