In this report
March 2010 Ratings

Plastic bags that protect food best

Last reviewed: March 2010
Strawberries in a plastic bag
In the bag
In addition to testing bags for leaks and breakage, we checked to see whether any kept strawberries or peppers especially fresh in the refrigerator.

To find out which bags are least likely to spill the beans, cookies, or leftover sauce by ripping or dripping, we tested 20. Some had press-to-seal tops, others used zipping sliders. Most hold 1 gallon. (Hefty OneZip Fresh Extend, whose packaging states "helps keep a variety of fruits & veggies fresh," holds 1.25 gallons.)

How we tested

We used a machine to test strength. To test leakage, we took three of every bag, poured 4 cups of water into each, sealed it, turned it sideways and upside down, and dropped it. We also stuffed bags to the brim with foam, tested moisture permeation, and checked whether any bags were especially good at keeping strawberries and green peppers fresh in the fridge. To check for freezer burn, we packaged steaks in all of the bags, squeezing out the air inside, and froze them for more than six weeks. And three panelists assessed convenience.

What we found

In a nutshell:

  • Freezer bags often cost more than regular storage bags but tend to be thicker and less apt to be damaged by pointy foods.
  • Press-to-seal bags were less likely than slider bags to pop open or tear when stuffed. Usually, any leaks emerged from the slider. No water-filled bags opened when dropped.
  • We found no discernible difference in how long bags kept peppers and strawberries fresh. In our limited tests, Hefty Fresh Extend didn't stand out.
  • No bag protected steak from ice buildup. A wrapping method that creates a tight seal should work better.
  • Some bags have open/close cues including arrows, labels, or a clicking sound on slider bags, or easy-to-grip tabs on press-to-seal bags. Some also have a place for you to write a date or other note.

Bottom line

For storage bags, try the Glad or Up & Up press-to-seal or the Great Value or Up & Up slider. Best freezer bags include two of the Up & Up brand and the Glad press-to-seal.

For a bag that sits upright, consider a Zip­loc expandable-bottom bag. Another option is Ziploc Evolve, which is claimed to use 25 percent less plastic than comparable Zip­locs and to be made using wind power. It was indeed thinner than other storage bags, but it's pricey and of average strength.

Whatever the bag, check unit prices. The number of bags per box differs widely and affects the cost per bag.