Kaffir Lime

Kaffir Lime, also known as Makrut Lime, is Citrus hystrix. Its strongly aromatic leaves and rind are used in Southeast Asian cooking, including soups and curries.^{⁠[1]⁠[7]⁠[8]}

The 1967 botanical treatment reproduced by UCR places Citrus hystrix in the traditional Papeda subgenus. This is a taxonomic classification. Its native habitat is described there as uncertain; UCR's Ceylon provenance and 1930 live-plant receipt concern accession CRC 2454.^⁠[1]

The fruit has an irregularly bumpy rind and can be oval to gently pear-shaped. UCR describes a small, shrubby plant with a broadly winged leaf stalk that can approach the blade in size. In Riverside, the collection notes year-round leaf use and fruit turning yellow and dropping at full maturity in late winter to early spring.^{⁠[1]⁠[11]}

Fruit reports differ. In a Bangkok market tasting, Weird Explorer rated a green fruit 10/10 for sourness and tentatively 3/10 for sweetness; a yellow fruit he considered ripe was rated 9/10 for sourness and had a harsh, vinegary flavor. Those fruits produced juice, whereas a Melbourne grower described his fruit as having none. These unidentified samples do not establish a general ripeness or juiciness rule.^⁠[5]⁠[4]

General growing descriptions call it frost-sensitive, but individual grower outcomes need their own context. A Melbourne grower reported vigorous growth after roughly ten years in the ground without giving a minimum temperature. A forum grower described a selected seedling and a nominal −3°C tolerance claim, separately from a −1°C to 5°C greenhouse range. Exposure details are incomplete, so these reports do not establish a cultivar-wide cold limit.^{⁠[3]⁠[4]⁠[10]}

UCR traces the historical name Kaffir to Arabic kafara and proposes a route into English through Indian usage associated with imported fruit. That route is explicitly tentative in the source. The catalog also retains Makrut Lime and Kafir Lime as aliases.^⁠[1]

A 2024 literature review surveys essential-oil, pectin and food-use research and notes that phytochemical composition varies with plant part and extraction method. Its cross-study findings do not define a single chemical profile for every tree or accession.^⁠[7]