Ma-Nao Dong — Preserved Limes / มะนาวดอง

Northern and Central Thai — less common in Southern and Isaan cooking; the technique reflects Indian and Persian culinary influence on the Thai court tradition

Salt-preserved limes (ma-nao dong) are made by packing whole or quartered fresh Thai limes in coarse salt for 3–4 weeks until the skin softens, the pith mellows its bitterness, and the salt-fermentation develops a complexity that fresh lime lacks entirely. The preserved lime skin and rind are the used portions — the interior is discarded. Used in Thai cooking primarily as an accent in certain Northern and Southern preparations, in drinks, and as a cleaning compound for certain earthenware vessels. The North African preserved lemon technique is the closest parallel, though Thai preserved limes tend to be packed with less salt and fermented for shorter periods.

Preserved lime's complex, mellow bitterness provides a note that no fresh citrus can — it is the difference between 'citrus' and 'preserved citrus', which are as different as fresh tomato and sun-dried tomato in their flavour contribution.