Relish and chutney are very similar condiments and the terms are often used interchangeably, but some general differences do exist. Chutneys are cooked longer than most relishes are. As a result, the texture and consistency of the two condiments tends to vary. Most chutneys are also sweeter than most relishes, but the taste of a chutney can be spicy or sour, as well. The biggest difference between relish and chutney, however, is where the two condiments originated.
In some senses, chutney is simply a type of relish with roots and flavors based in Indian cuisine. Both relish and chutney are condiments made from small pieces of fruits or vegetables mixed with spices and other flavors. Relish is a general term for all such condiments and appears throughout various western cuisines, but chutney, a derivative of the Hindi word chatni, dates back to 15th century Eastern India. Chutney only came to western cuisine in the 17th century when it was first shipped to Britain and France.
Relishes are cooked for a brief amount of time. Chutneys, on the other hand, can either be served fresh or slow-cooked. Traditional Indian chutneys are more likely to be served fresh, while western versions are generally cooked over low heat for an extended period of time. Most commercially-sold chutneys are also made using the slow-cook method, since traditional Indian chutneys are usually prepared without preservatives and are meant for immediate consumption.
Both relish and chutney contain small pieces of fruits or vegetables in an acidic, sour liquid, but the texture of these pieces often varies, as does the consistency of the liquid. Most homemade and commercial relishes have crisp, crunchy pieces. If a homemade chutney is fresh, it may also consist of crunchy pieces, but slow-cooked chutneys are softer. Relishes also have a more fluid, liquid consistency, while most chutneys are as chunky and spreadable as a jam or other preserve.
Taste is a relatively inconsistent way to tell the two condiments apart. Relish and chutney both have an undertone of sourness, primarily because most recipes for both condiments include some type of tangy liquid, such as lemon juice or vinegar. Most chutneys include more sugar than relishes, and as a result, many automatically assume that any chutney will be sweeter than any relish. Some relishes are actually sweet, however, just as some chutneys can be spicy or savory.
Traditional chutneys were actually very tangy, but after Britain and other western cultures brought chutney into their own cuisines, the condiment took on a notably sweeter taste. Even westernized, modern day versions of chutney still include traces of Indian flavors, however. Individuals making chutney typically include spices native to India, including but not limited to ginger, cinnamon, coriander, turmeric, chili pepper, tamarind, nutmeg, and allspice. The combination of these spices determines whether a chutney will taste savory, sour, sweet, or spicy. Relishes, by contrast, contain far fewer spices and are generally either tangy or mildly sweet.