Insider notes
Things to know before you book
The Devour Tours question
Two tours on this list are run by Devour Tours (numbers 2 and 4). They're the most expensive options but consistently the best-reviewed operator in Madrid. If your budget allows one of them, take it. If you'd rather save €30 per person, the Gourmet Madrid tour (number 1) is a fine substitute.
La Latina vs Centro
Both are central Madrid neighborhoods and both have great food, but they're stylistically different. Centro (around Plaza Mayor) is more polished, more historic, more tourist-mixed. La Latina, immediately south, is grittier, louder, more locally-oriented, especially on Sunday afternoons. Tours in both are worth doing. If forced to pick one, La Latina rewards repeat visitors while Centro is more first-timer friendly.
Vermouth hour
Madrid takes vermouth (vermut) more seriously than any other Spanish city. Between noon and 2pm on weekends, locals gather at neighborhood bodegas for a glass of vermouth on ice with a slice of orange, plus a small tapa, an olive, a piece of anchovy on bread. It's a ritual, not just a drink. Several of the tours above include vermouth hour. If you can only add one Madrid food experience beyond a meal, make it a proper Sunday vermouth at Casa Alberto, Casa Labra, or La Ardosa.
When to book
Madrid tours generally have more availability than Barcelona, but the top-rated ones (Devour, Gourmet Madrid) sell out 4-7 days ahead in peak season (May-June, September-October). Weekends fill first. Book at least a week ahead for weekend tours. Weekday tours can often be booked 2-3 days in advance.
Timing
Most Madrid dinner tours start at 7-7:30pm. This is 2-3 hours before Madrid residents typically eat dinner, which is intentional, tours run early to hit the bars during their setup phase when guides can talk to the owners. If you want the loud, full-of-locals Madrid nightlife experience, plan a separate late meal after your tour ends around 10pm.
For related reading: how to order tapas in Spanish, how tapas actually work in Spain, and what to eat in Barcelona if you're combining trips.