In general, relishes are very similar to chutneys except they are usually more finely textured and may resemble a chunky sauce. Ketchups and sauces are often sieved to obtain a creamy, lump-free consistency. The difference between ketchups and sauces is that ketchups have one predominant flavor like tomato or mushroom or anything you like while sauces have a larger number of ingredients.
All of these methods involve a certain amount of vinegar in their preparation, so avoid using iron and copper utensils. All should be stored in sterilized jars or bottles with airtight lids. Somme of them require a period in a water bath similar to the bottling process. The finish products will store for several months and once opened should be kept in a fridge.
The basic method is similar to the one used for chutneys. Make sure you use young, unblemished vegetables. Clean and chop them using a mincer or food processor. Place them in a large pan with salt, sugar, vinegar and spices and simmer until tender then sieve them if you are making ketchups or sauces. Put them in sterilized jars or bottles while hot, put lids on tightly and store in a cool, dark place.
