A shopper with a baby in a carrier checking to see if produce is really organic.

Yes, if a packaged item carries the Department of Agriculture organic seal, it must meet the USDA's standards. Among other things, these require that crops be grown without most synthetic pesticides or fertilizers, or genetically engineered seed.

Farms must be certified by a USDA-accredited certifier and include an annual inspection to make sure they are complying with the standards, says Charlotte Vallaeys, M.S., CR's senior food and nutrition policy analyst.

More on Food Shopping

But you often won't see the USDA seal on loose, unpackaged produce, such as apples. In that case, look for a sticker or band that has a price look-up (PLU) code. Conventional produce PLUs have four digits and organics have five—and the first number will always be 9 if the produce is organic.

For example, apricots' PLU is 3422 for conventional and 93422 for organic. (Note that genetically engineered produce used to have PLUs that started with 8, but that isn't true anymore; PLUs no longer indicate this.)

Although PLUs aren't mandatory or regulated by the government, these numbers are used widely around the globe for pricing and inventory control, so they're generally reliable—and good for astute shoppers to know.

For related food shopping tips and tricks, read "Health Claims on Food Labels: What's True, What Isn't" and our recent article on the "Grocery Stores With the Best Fresh Produce."

Editor's Note: This article also appeared in the June 2019 issue of Consumer Reports magazine.