As a millennial kid growing up before eco-friendly-everything was commonly available and sought-after, I remember a big roll of Saran wrap always hanging out in the kitchen cabinet. Leftovers of all kinds, from raw steaks to casseroles to pudding to brownies, were stored in their cooking or serving vessels, but with a tight layer of plastic wrap stretched over the top. That just seemed like the obvious way to protect food from oxygen, insects or weird fridge odors.
But as I’ve grown up and started to pay more attention to my plastic usage, I now wonder whether my mom’s supposed failsafe method really keeps cooked dishes and raw ingredients fresh.
I turned to a food scientist, an attorney who specializes in foodborne illnesses, and a number of academic sources to dig into these questions, and here’s what I learned.
Plastic wrap is an effective storage solution because it protects food from air and particle exposure.
Simply put, plastic wrap — which is usually made of food-safe low-density polyethylene, or LDPE — “is actually quite effective because it’s able to produce a very stable and tight seal at the edges of a container,” said Bryan Quoc Le, founder and principal food Consultant at Mendocino Food Consulting.
This wrap is designed to cling, so “by reducing the ability of particles and air to come in contact with the food, food can stay fresher for a few more days, so long as contamination has been limited between when the food was cooked and when it was stored,” Le continued.
Most plastic wraps are designed to work in the fridge and freezer, and they often work better at colder temperatures.
Plastic wrap can certainly be used to store items at room temperature (like pastries and breads), but Le told us that it truly comes into its own when it’s exposed to cold temperatures. “Plastic wrap can increase its stickiness when used in the freezer, and is actually quite effective at colder temperatures,” he said. Essentially, when it comes to plastic wrap’s fresh-sealing power, the colder, the better.
As far as specific timing goes, Le explained that “plastic wrap can extend the freshness of food by about a day or two at room temperature, by three to four days in the fridge, and for several months in the freezer so long as there is as little air as possible between the food and the plastic wrap.”
In fact, he generally recommends reserving plastic wrap for freezer and fridge storage. “It’s best to use plastic wrap for foods that you want to store for long periods of time [in the freezer] because of its ability to limit moisture and air transfer from and to the food. That is where plastic wrap is most effective,” Le said. This long storage idea also applies to the use of plastic wrap in the refrigerator: “In some cases, like [with] cheeses or preserved meats, plastic wrap does truly shine in its ability to keep these foods fresh even in the refrigerator because these foods last quite a while. Most foods with a long shelf life in the refrigerator can become rancid if exposed to oxygen, so using plastic wrap in this case to protect these foods is beneficial.”
For shorter-term storage (like a dish that will be eaten soon after placing it in the fridge or a fresh-baked pastry that will be stored on the countertop until it’s eaten within a couple of days), Le recommended using “a plastic or glass container” instead of plastic wrap.
Plastic wrap shouldn’t be microwaved unless it has a microwave-safe symbol on the packaging.
Since Saran Wrap switched from the stronger PVC plastic to the reliably food-safe LDPE in the early 2000s, plastic wrap as a general category has been considered very safe by food professionals and the medical community. The one exception to this principle involves plastic wrap that’s exposed to heat.
The American Osteopathic Association — a medical organization representing osteopathic physicians — explains that not all types of plastic wrap are microwave-safe, and that if a non-heat-safe plastic is exposed to that type of heat while in contact with food, the plastic itself can melt or leach chemicals into the food item.
For that reason, it’s crucial to check the packaging of your plastic wrap to make sure that it’s specifically designated as microwave-safe. Also, when putting plastic wrap on food before microwaving, follow the AOA’s advice and “leave at least one inch between plastic wrap and food before heating.”
While plastic wrap generally can’t be recycled using curbside pickup, many grocery stores and retailers have drop-off bins.
If you, like me, have concerns about plastic wrap’s effect on the environment, you may be relieved to learn that, contrary to popular belief, it is often possible to recycle plastic wrap after use. The only catch is that this type of plastic can’t currently be recycled through curbside pickup.
But according to America’s Plastic Makers (a nonprofit group of scientists, engineers, designers and technicians dedicated to finding a most sustainable future for the plastics industry), “there are thousands of retail stores and drop-off centers that accept plastic film packaging for recycling. You likely have seen the recycling bins outside/inside many large retailers. These retailers collect plastic film packaging from consumers like you and from back-of-the-store packaging, [and] they haul this plastic film to multiple businesses that recycle it into new products.”
Eco-friendly alternatives to plastic wrap include reusable silicone covers and beeswax wrap.
Plastic wrap can be part of sustainable kitchen storage practices (which is very good news for my mom and other folks who feel attached to this convenient stretchy stuff), but other alternatives exist that further improve on the eco-friendly idea. “Reusable food storage bags made from food-grade silicone may be a safer alternative to disposable, single-use plastic bags or even plastic wraps,” said Jason Reese, co-founder and partner attorney at Wagner Reese, a firm specializing in personal injury and foodborne illnesses.
Sealable silicone containers and silicone covers (which can be snugly fitted over a bowl or serving dish) are easy to clean and durable options; Iowa State University researchers said that “per the FDA, food-grade silicone is safe and will not react with other materials or release hazardous compounds or fumes when heated. Food-grade silicone is safe to store food, put in the microwave, freezer, oven and dishwasher without hardening, cracking, peeling or becoming brittle as it is resistant to extreme temperatures; It will not leak, break down, or degrade over time.”
Another popular swap-in for plastic are food wraps coated in beeswax. The University of California Agriculture and Natural Resources praised beeswax wrap by saying that it “presents a sustainable and eco-friendly alternative to plastic film wraps. In contrast to plastic wraps that contribute to pollution and have a slow decomposition process lasting years, beeswax wraps naturally break down, mitigating their environmental impact.”
However, they do acknowledge that “beeswax wraps are not recommended for use with raw meat or hot items, as the heat can melt the wax coating. This limitation may affect their practicality in certain cooking and food storage scenarios.”