Tamarind paste is the processed pulp of the tamarind fruit. It is a souring agent popular in Indian cuisine for its ability to provide a tangy acidity to dishes along with mildly sweet notes. You can buy pre-made tamarind paste or a block of tamarind pulp that you can reconstitute to make your own paste. If neither option is available to you, consider one of the many tamarind paste substitutes.
Your best bet: Pomegranate molasses
Pomegranate molasses is a reduction of pomegranate juice. The juice has been reduced to the point where it becomes thick and syrupy but without being overly sweet. In fact, pomegranate molasses is typically used to provide acidity rather than overt sweetness.
The consistency of pomegranate molasses is a big part of what makes it an excellent substitute for tamarind paste as both of them bring moisture to a dish. It also provides dishes with a darker color, which is one of the effects of tamarind paste.
When using pomegranate molasses as a substitute for tamarind paste, use the same amount that your recipe requires for tamarind paste.
A decent second choice: Citrus juice
Lemon and lime juice are two of the most readily available souring agents and are popular for providing tartness in western cuisine. Tamarind fulfills that same role in Indian cuisine while also providing a fruity sweetness that you will not get from lemon or lime juice. Even so, tart citrus fruit can still do an effective job of standing in for tamarind paste. In fact, Indian cooks often use lemon or lime to replace tamarind when they need a substitute. If you are making a Thai dish and absolutely need the sweetness, consider adding sugar to slightly sweeten the juice and your dish.
When using lemon or lime juice as a tamarind paste alternative, add the same amount of juice that your recipe requires for tamarind paste. If you decide to add sugar, add equal parts sugar and citrus juice. Use the same amount of the mixture that your recipe requires for tamarind paste.
In a pinch: Mango powder
Mango powder or amchur is made from dried and powdered unripe mangos. While tamarind paste is more popular in southern India, mango powder is the preferred souring agent in the northern part of the country. The fruitiness and tartness that mango powder provides are similar that to that offered by tamarind paste.
The big difference is the consistency since mango powder is dry. You can increase mango powder’s similarity to tamarind paste by making a paste with it. Use equal parts mango powder and water. Add the same amount of the mango powder paste to your dish that the recipe indicates for tamarind paste.
Kokum is a fruit that has many of the same souring qualities as tamarind. Native to southern India, it is rarely used anywhere else. To use kokum, you will need to soak it in water and add it whole to the dish. As with fresh tamarind or unprocessed tamarind pulp, you will need to check for seeds.
Kachri powder is another local Indian seasoning that is almost unknown outside of India and rarely used outside of the Indian state of Rajasthan. The kachri is a relative of the cucumber and has a tart taste when dried and powdered.