A pasta-filata cheese, made far from Italy
Quesillo is a fresh pasta-filata cheese: a curd from cow’s milk is acidified, then heated in hot water and kneaded and stretched until it becomes elastic and forms long ribbons (the hebra, “thread”), which are then wound into a ball like a skein of yarn. Cut into a wedge, the ball reveals concentric layers that pull apart into strands — hence the alternate name queso de hebra. The technique is the same family as Italian mozzarella, provolone, and string cheese, but its emergence in Oaxaca is independent of post-conquest Italian immigration.
Origin: Reyes Etla, attributed to 1885
The widely-circulated origin story credits Leobarda Castellanos García of Villa de Reyes Etla (in the Etla valley north of Oaxaca city) with the invention around 1885, said to have happened by accident when a 14-year-old Leobarda left curd too long, and tried to rescue it by pouring hot water over the failed batch — the curd stretched, and quesillo was born (Lopez 2019; Gob. Oaxaca 2021). The 1885 date and Castellanos attribution are repeated in state government materials backing the denominación de origen filing, but a hard primary document (parish record, 19th-c. local press) is not commonly cited; treat the date as the conventional attribution rather than a verified historical fact. Reyes Etla still hosts an annual Feria del Quesillo.
Why it strings
The pasta-filata step works because curd held at the right pH (~5.2) and temperature (~65–70°C) realigns its casein proteins into parallel fibers when stretched. The resulting cheese is mild, salty, melts cleanly, and pulls into long strings when warm — properties exploited in quesadillas, empanadas de amarillo, molletes, tlayudas (the white snowfall on top), chiles rellenos, and memelas.
“Oaxaca cheese” in US supermarkets — and the denominación de origen pursuit
What US supermarkets sell as “Oaxaca cheese” or “queso Oaxaca” is almost always industrially produced in the United States or in non-Oaxacan Mexican states, and frequently lacks the moisture, milkfat, and hand-stretched layering of artisanal Reyes Etla quesillo. Since the early 2010s the Oaxaca state government and a producers’ consortium have pursued a Denominación de Origen (DO) for Quesillo de Oaxaca to restrict the name to product made within designated municipalities of the Etla valley using cow’s-milk pasta-filata methods (Gob. Oaxaca 2021). As of this writing the DO has not been finalized at the federal IMPI level — Oaxacan producers continue to lobby.
Where to buy in LA
Guelaguetza (3014 W Olympic Blvd) sells artisanal-style quesillo by the ball, often imported through Oaxacan-owned distributors. La Mascota Bakery and Vallarta Supermarkets stock domestic “queso Oaxaca” — usable but distinct from Reyes Etla product. Mercado Olympic vendors carry hand-wound quesillo on weekends. Sabores Oaxaqueños uses quesillo on its tlayudas and quesadillas.