One in five Americans has access to legal weed, which means they can drop in at their local dispensary, browse a menu of marijuana varieties, and buy without a doctor's note.

While the days of buying marijuana in a back alley from your college roommate's cousin's friend may be nearing an end, there's often still confusion on what kind potency various strains have and where it comes from. These specs aren't always clearly labeled.

Jessica Catalano, a chef and author of "The Ganja Kitchen Revolution," knows good weed. She is a pioneer of cannabis cuisine, which infuses or pairs food with specific marijuana strains based on their flavor profile. The "pot sommelier" has smoked ganja for roughly 20 years.

When Catalano, who uses cannabis to treat her migraines, is making edibles or preparing pairing dinners, she looks for several characteristics in her bud. A stalk of weed should be dense with flower — the fluffy, green stuff you smoke.

"You want it to look healthy and covered in crystals [as] if someone took really fine particles of diamonds or snow and sprinkled it all over the cannabis," Catalano said.

A healthy nug has a light frosting of crystals. Shutterstock

There are several signs of stress that users can look for: brown or orange spots might mean the plant grew in an environment that was too hot, while a sparse bud might indicate the plant was exposed to excessive wind.

After marijuana is harvested but before it ends up on shelves, the plant undergoes a process called curing, in order to remove moisture from the flower and preserve its flavor and quality. A stalk of weed should not be bone dry. Instead, it should be springy when you pinch the bud between your fingers. If it retains the shape it's been squeezed into, it probably wasn't cured properly, according to Catalano.

Usually, dispensaries leave samples of different strains in jars on the counter. You can ask a dispensary employee, called a "budtender," to examine the buds more closely and find out which (if any) strains were organically grown. Most employees receive extensive training to understand the plant and learn the nuances between different strains.

In Jessica Catalano's kitchen, a mixed berry compote is made with marijuana kush. Tyler Kittock

When it comes to smell, it's buyer's choice. Different strains can smell like citrus, pepper, or even baking spices. Catalano warns that you might make some poor choices along the way.

"I thought it was a great idea to infuse a strain called Kong into chocolate chip cookies. Kong is a very robust strain that tastes like fuel when you vaporize it — fuel and skunk," Catalano said.

The result was "catastrophic." Eventually, she figured out the winning combination.