Check the looks before you start squeezing the produce
You’ve seen shoppers get handsy with the produce, squeezing avocados and groping onions. It’s really not necessary.
“For most produce, the freshest vegetables should be easy to see,” says Crannell. “Check for bright colors. For peas, beans, green garlic, and springtime veggies, it should be the color that inspires you first.”
Certain foods will darken as they ripen, but brighter colors tend to be a good indicator of how long it took them to get to market. Check for vine-ripened tomatoes, which means they were picked right as they started changing color to arrive fresh at the market and not soft or soggy (and the vine should still be attached). Asparagus and artichokes should have no brown at their tips, and fruits should have smooth rinds (fine, you can touch the fruit but don't be weird about it).
Pay attention to the leaves
Like a psychic with tea, you’ll want to learn how to read the leaves to find the freshest produce. A good vendor won’t remove the leaves from their stock, allowing you to get a sense of how recently it was picked -- look for green, full, healthy growth as a sign of freshness. This is especially true for root veggies like carrots and beets, where the leaves will show signs of age before the rest of the plant.
And beware the herbs at farmers markets. “You’ll see herbs that are wilted, because they waited a few days and didn’t want to refrigerate them,” says Cervantes. You might as well be buying already-stale bread.
Talk to the farmers
Both chefs stressed that talking to farmers was the best way to get the most out of shopping at a farmers market. After all, it’s not like the people working at the supermarket are also the ones growing the food. You need to groom your chosen farmer-friend like you’re planning on asking him or her to the prom. So don’t be shy; ask about when produce was harvested, what conditions are like for animals, and even for recipe advice.
Build connections to get the freshest seafood
Getting the freshest seafood can be tough if you’re not near the coasts, especially since many farmers markets don’t run every day. Vendors at smaller markets sometimes have no choice but to serve up catches that have been sitting on ice for a day, which you’ll want to avoid. Talk to fishermen who bring their catches to market, and get info on when they were caught.
“When they pull into the harbor, fishers will text me a whole sheet of what they’ve brought in, so I can select what I’m looking for,” says Crannell. You’re probably not trying to get those fish-pics on your phone (unless that’s what you’re into), but asking can still help you get the best of the catch.
To test if a fish is fresh, ditch the no-touching rule (if you’re allowed). Firmness is key -- the fish should bounce back when you poke it, not sag like a memory-foam mattress. And as strange as this sounds, it shouldn’t smell too fish-y -- really fresh seafood smells like the sea it came out of.
Buy your basics at the market
Farmers markets have a reputation for offering gourmet, specialty foods, but the basics are where they really excel. In any complex dish, it’s the standard ingredients like eggs, milk, and flour that will have the biggest effect on the flavor. For that reason, it’s best to get these from a farmers market, where you can be certain of the quality and freshness. Think of it as though you’re building a skyscraper: don’t worry about the observation deck until you’re certain the foundation is solid and you've gotten the necessary building permits and union labor... OK maybe it's not entirely like building a skyscraper.
Try out different varieties of vegetables
Farmers love to grow small-batch vegetables, like multi-colored carrots and potatoes with a much wider range of flavors than supermarkets carry -- sorry, Red Delicious. Some are even breeding their own varietals with their own cooking characteristics -- not something you can identify on-sight.
So what are you supposed to do with these unknown veggies? Farmers have seen their crop from a seedling to a full blown potato, so you best believe they know which spud is better for boiling and which is better for roasting, just ask.
Don’t buy out of season
When you’re buying from a farmers market, you're assuming the goods are in season and produced by sylvan elves and fertilized by whimsy... but some farmers might take shortcuts, like growing produce in greenhouses to imitate a natural growing season. A quick search for "local harvest calendar" and "your geographic region" should reveal what is and isn't in season, hopefully protecting your from farmer bamboozlement.
Improvise your menu, rather than sticking to one plan
If professional chefs can ditch lists and menu plans based on what looks the best at the market that day, so can you.
Cervantes says you must be open to changing your specials and choosing what’s there, instead of trying to source ingredients that fit your recipe. “It’s not me telling the vegetables to be ready,” he says. “The vegetables are telling me when they’re ready.” Warning: no matter how fresh, vegetables should not be talking to you. That said, yeah, just go with the freshest flow, man.