Philippines (Tagalog region; pan-archipelago variations with different souring agents)
Sinigang na baboy is the Philippines' most beloved sour soup — pork ribs or belly in a tamarind-based broth with kangkong (water spinach), long green beans, radish, eggplant, tomato, and onion, seasoned with fish sauce and seasoned with the characteristic souring agents that vary by region: tamarind (sampalok) in Tagalog regions, guava in Bicol, kamias (bilimbi) in Visayas. The sour broth is not a background note — it is the dominant flavour profile, and the sinigang should be bracingly, unapologetically sour. The pork provides richness against the acid; the kangkong and vegetables soften in the hot broth but must retain slight colour; the fish sauce provides depth without fishiness. Sinigang is comfort food of the highest order in the Philippines.
White rice is mandatory: the sour broth is eaten with rice, with each spoonful alternating between the rice and the soup; patis (fish sauce) at the table allows additional seasoning.
{"Sourness must be assertive: timid sourcing produces a weak sinigang — the acidity should tighten the jaw.","Tamarind cooked with the pork from the start provides the best flavour integration: tamarind powder or paste added at the end produces a less rounded acidity.","The pork must be blanched before the final broth is built: the scum from the initial blanch would cloud the broth.","Vegetables are added in descending order of density: radish, then eggplant, then green beans, then kangkong last.","Fish sauce is the salt: regular salt cannot replicate the umami depth of fish sauce in a Filipino broth."}
Use fresh tamarind pods (not powder or paste) and simmer them in the broth until fully dissolved before straining — fresh tamarind has a complex combination of tartaric acid, malic acid, and natural fruit sugars that powder cannot replicate, producing a more rounded, nuanced sourness.
{"Insufficient sourness: adding too little tamarind produces a pork broth that happens to be slightly sour rather than a sinigang.","Adding all vegetables at once: firm vegetables become soft while leafy vegetables become mushy.","Skipping the blanch: unblanched pork produces a grey, scummy broth.","Using tamarind concentrate in excessive quantities: tamarind concentrate is more concentrated than fresh tamarind — measure carefully."}