Open-air food markets are not terribly common in Buenos Aires. Most flea markets and fairs in the city will have street vendors who sell some food, like churros, coffee, freshly squeezed orange juice, empanadas, and pan relleno (bread stuffed with meat and cheese), which are designed to keep your energy up for the hours of perusal ahead, but the majority of the stalls are dedicated to the artisans.
In the San Telmo neighborhood, however, there are two markets that sell food. One is a covered market, the Mercado San Telmo, entrance at the corner of Carlos Calvo and Bolívar streets. You can find clothes, antiques, and flowers, but the main staple of the market is the produce section. The Mercado is open all week long (3-7pm Mon-Fri, and 9am-8pm Sat-Sun).
A smaller market that is dedicated to just food is also located in San Telmo, on the corner of Mexico and Balcarce. Only on the weekends, the vendors park their carts and open up shop for people looking for meat, eggs, fruits, veggies, and fresh herbs. Be careful buying any meats or eggs during the summer months, as the carts are not safely cooled. However, the produce is fresh and very inexpensive all year long. A bag of six oranges might cost you AR$4, or less than US$1. A kilogram of ground beef will cost around AR$9. This market is small and its schedule is unreliable. Bargaining is acceptable, but be sure to take cash in small denominations with you, as the vendors may be reluctant to make change and won’t accept credit cards.
The Belgrano neighborhood has a large covered food market, called the Feria Modelo de Belgrano. It’s located at Juramento 2527, where Ciudad de la Paz intersects (Mon-Sat 8-1pm and 5-8:30pm). Here you can find highly specialized gourmet food from Argentina, like meats and fish from Patagonia, and cheese from throughout the interior of the country.
The Feria de Mataderos (Av. Lisandro de la Torre &Av. de los Corrales, hours vary) also has an assortment of foods from the interior, including cheeses, cured meats, olive oil, and sweets filled with dulce de leche (the Argentine relative of caramel). It’s located in the southwest of the city in a blue-collar neighborhood unknown to most expats, but if you’re up for making the trip for the fair’s folkloric experience (see the ‘Flea Markets’ section for more), the food is worth it.