The pods of the tamarind tree contain large seeds surrounded by a fleshy pulp. It is this pulp that used in cooking as a souring agent.
Another souring agent commonly used is kokam, which is confusingly called fish tamarind in some places. They are not related, and are not really interchangeable.
The taste of tamarind is best described as fruity, sweet and sour. The fruit is high in B-group vitamins and calcium.
To use it, you crack open the pods, which can be hard, and discard the seeds and the hard fibres. You will be left with the dark fleshy pulp, which is what is used to cook with.
Whilst fresh tamarind pods are very difficult to source, certainly in Sydney, the pulp is readily available as compressed blocks from Indian grocers. This is called tamarind paste and must not be confused with tamarind concentrate, which is a processed form of the pulp, ready for dilution.
Tamarind paste in the most common way to buy and use tamarind.
When buying tamarind paste we usually select the seedless variety as it is slightly easier to work with. Most of these preparations discard the hard fibres as well as the seeds.
Depending on the use, the pulp is processed in one of several ways. The most common form in this cookbook is to steep the pulp in water to make tamarind water.
Tamarind concentrate is another way to buy tamarind. It is readily available, often in supermarkets. It is a concentrated form of tamarind water and is a good substitute , if all you need is tamarind water. Typically you dilute one teaspoon of concentrate in one cup of water to make tamarind water. This tamarind water is used extensively as an ingredient throughout this book.
Once opened, a block of tamarind paste will keep for about a month, if sealed and kept in the refrigerator. Fresh seeds and pods only have a shelf life of a week or so.