Cows are “grass fed” for most of their lives. After about 10 months, “grass finished” cows will continue on a grass or pasture diet, while conventionally raised cows will be fed grain for the next four months or so. (Justin Sullivan/Getty Images)

Grass-fed beef sounds like a lovely idea. Customers envision happy cattle grazing on green pastures, producing meat that is better for our health and the environment. It turns out that none of this is a given. The jury is still out on whether grass fed beef is better for the environment (it’s only slightly better nutritionally), and, “grass-fed” doesn’t mean a cow was never served grain. Other aspects about grass-fed beef that may surprise many consumers include that it tastes different from grain-fed beef, and can be trickier to cook.

Still, people are buying it. According to Nielsen data, retail sales of labeled grass-fed beef are booming, increasing from $17 million in 2012 to $272 million in 2016, although it only makes up an estimated 3 percent of U.S. beef.

Because grass-fed beef is more expensive than conventional beef, customers should know how to decipher the different beef labels to determine what you’re getting, and how to prepare it for the best results.

How to decipher the labels

Grass fed, grass finished, pasture raised and organic: What does all the terminology mean? It’s more complicated than you’d think.

Let’s start with grass fed. Cows are “grass fed” for most of their lives. After about 10 months, “grass finished” cows will continue on a grass or pasture diet, while conventionally raised cows will be fed grain for the next four months or so. You may also see labels such as “more than 80 percent grass-fed diet” on beef packaging to reflect that the animal’s diet was switched to grain or included some grain. And keep in mind that “grass fed” or “grass finished” only tells you what the animal was fed. It doesn’t tell you anything about whether the animal roamed outside or whether antibiotics or hormones were added to its feed.

The Agricultural Marketing Service (AMS) of the Agriculture Department used to have a standard for Grass (Forage) Fed meat but withdrew it in 2016. Beef producers still need to apply to the USDA’s Food Safety Inspection Service (FSIS), however, if they want to put “grass fed” on their labels. The required documentation includes written and signed descriptions of how the facility ensures that the claim is accurate. These claims are verified by independent AMS auditors before they can be used on packaging. The same process applies if producers want to put claims about the use of antibiotics or hormones on their labels.

Animal welfare and environmental claims such as “humanely raised” and “sustainably farmed” can also appear on labels with FSIS approval, although FSIS doesn’t define what these terms mean. It’s up to the producer to put an asterisk next to the term and define it somewhere on the label. Bring your glasses and get ready to do lots of reading and comparing when shopping for beef.

There are also independent third-party verification services for grass-fed beef such as the American Grassfed Association and the Food Alliance Certified Grassfed program. Both certification programs include unscheduled visits and inspections of facilities. They also go beyond grass fed to include standards around animal welfare and environmental practices and require that no antibiotics or hormones have been added. The documentation from these inspections can be sent to FSIS so that claims such as “grass fed,” “grass finished,” “pasture raised,” “raised without antibiotics” and “raised without the use of hormones” can be put on the label. One of the merits of these certifications is that their stamp of approval encompasses multiple concepts so they don’t all need to be written out on the label. The problem is that the average consumer doesn’t know that “grass fed” written out and the “American Grassfed” symbol have such different meanings.

“Pasture raised” means the cows spent some time outside, but it doesn’t necessarily mean they were grass finished. And their diets could include some grains, so they aren’t necessarily 100 percent grass fed.

To further add to the confusion, grass feedlots have recently emerged, where cows are fed grass or grass pellets indoors, so a cow might indeed be grass finished but not, as one would imagine, pasture raised.

“Natural” is one of the most meaningless claims you’ll see on labels. Beef can be labeled as “natural” if no artificial ingredients or colors have been added. This label doesn’t reveal anything about what the cow was fed or how it was raised.

And grass finished doesn’t necessarily mean organic. The addition of hormones or antibiotics isn’t permitted in organic beef, but can be in grass-fed beef. Conversely, organic beef isn’t necessarily grass fed; the cows could have been finished on organic grain.

It’s no wonder consumers are confused by all the claims on labels.

If you want more information about how your beef was produced, ask plenty of questions. When possible, go visit the farm yourself. Other options include choosing beef from trustworthy farms or brands with transparent practices and clear labeling. You can always call them and ask if you’re unsure about something.

How to cook the beef

Grass-fed beef is a whole new flavor experience. It’s often described as having a richer, meatier and more complex flavor, while grain-finished beef tends to have a milder, sweeter flavor.

Grass-finished beef also cooks differently than conventional beef. Sarah Russo, the chef at Pre Brands, a company that sells only grass-fed beef, recommends preparing grass-fed steaks by patting them dry and then rubbing both sides with kosher sea salt and high-heat oil such as avocado oil.

“Grass-fed beef cooks up much faster than conventional beef,” Russo explains. “The reason for that is there’s less fat in grass-fed beef, so the moisture inside can flow more freely and comes to a boil much faster than in conventional beef.”

The first couple of minutes of cooking a grass finished or grain-finished steak are similar, but as soon as the moisture reaches the boiling point, the grass-fed steak can go from medium-rare to medium well very quickly.

To check for doneness, Russo suggests using a digital meat thermometer and employing the “triple check” method. Take the temperature of the steak three times, in different parts of it. Your lowest temperature should be about 105 degrees Fahrenheit to get a medium-rare steak. When cooking is done, don’t forget to let your steak rest a full six minutes to let the temperature and juices redistribute.

Christy Brissette is a registered dietitian, nutrition writer, TV contributor and president of 80TwentyNutrition.com. Follow her on Twitter @80twentyrule.