14Inside Somerville’s Union Square Donuts, the mood is fun, like its gigantic crave-worthy maple bacon doughnuts. 6Carrots get rinsed before being boxed for that day’s farmers’ market. 16Sarah Willis (from left) and Hillary Brown roll pastry dough inside the kitchen. Their work typically starts around 4 a.m. 3On a harvest morning, Dave Purpura directs workers Ron Aakjar (left) and Tim Birnstiel. 1Farmer Dave Purpura named his Middleboro, Mass., farm Plato’s Harvest after his beloved pet goat. 10Anyone can take a tour of Taza’s Somerville factory. Here, tour leader Krysia Villon explains the three-day production process, which includes grinding cacao beans and wrapping the chocolate. 5Dave Purpura steps in the pen to feed — and pet — his pigs. If there’s anything more delicious than a newly picked, vine-ripened tomato or fresh golden corn, it surely must be chocolate or a sticky, carb-laden confection. All are available at the Harvard Farmers’ Market, held weekly at the Science Center Plaza and in Allston. But their origins may surprise you.Knowing where food comes from has never been more important in an age of global commerce and public debates over factory farming and genetically modified foods. This ethos is part of the farm-to-table movement, which emphasizes local foods such as those sold by the farms and vendors that serve the Harvard Farmers’ Market.Taza Chocolate is one such vendor. Producing circles of stoneground chocolate in nearby Somerville, Taza is committed to sustainability, even as it sources cocoa beans from Bolivia, Belize, and the Dominican Republic. By dealing in direct trade with certified organic farms in these countries without a middleman, Taza can pay cocoa farmers well above market wage. The beans head straight to Somerville, where they’re turned into chocolate.Right down the road at Union Square Donuts, production workers arrive at the break of dawn, ready to hand-roll, cut, fry, and glaze fresh doughnuts before most people have even hit the snooze button. They work mostly in silence, save for the noise from a radio and the phone, which rarely stops ringing. A good doughnut is hard to find.Farther off, in Middleboro, Mass., roosters signal another day on the farm for Dave Purpura, who rents his acreage for Plato’s Harvest Organic Farm. The former software engineer has been farming for nearly a decade. He and a few farmhands transport the day’s harvest to Purpura’s home, where it’s rinsed and boxed before it’s sent to farmers markets.The tableau of animals, cornstalks, and countrymen makes for a cinematic, even romantic, view. “Everyone thinks that until they get out here for a few hours, and it’s 90 degrees, and the romance goes out the window,” said Purpura. It’s hard work that makes a farm work.Additional reporting by Crystal Chandler. 19Fresh-cut doughnuts, ready for the sputtering oil. 4Ron Aakjar plucks squashes for the day’s farmers’ markets. 2Chickens graze between the rows of produce at Plato’s Harvest. 11Taza’s chocolate is an organic, vegan, dairy- and gluten-free treat. 7Tim Birnstiel shakes off some greens. 18Production manager Kristen Rummel counts and boxes doughnuts intended for afternoon’s farmers markets. 17Paige Degeorge (from left) and Dominic Dellaquila work on a batch of doughnuts. 15Union Square Donuts co-owner and pastry chef Heather Schmidt tapes up the week’s farmers’ market schedule. 20Sarah Willis strikes an artful balance carrying doughnuts to the walk-in fridge to chill. 8Founded in 2006, Taza specializes in Mexican-style chocolate. 9Taza participates in direct trade with organic cocoa farmers in Bolivia, Belize, and the Dominican Republic. Although not used in chocolate production, shells from the beans can be used for tea, mulch, and as a natural termite repellant. 13Taza employees prepare the final product for wrapping. 12Using stone mills instead of steel mills like most chocolate on the market gives Taza products a unique, grainy texture.