Any good substitutes for tamarind in Beef Rendang? I have seen recipes for Indonesian Beef Rendang that call for tamarind (here is one), but tamarind is a little difficult to find here in Japan. So I have two questions:


What could serve as a substitute for tamarind in a Rendang recipe?
And what does tamarind do for Rendang, exactly?
Tamarind gives a sour and slightly molasses note to food, including rendang. To replicate it, you thus need something sour, like lemon juice, and a dark sugar flavour, like black treacle, molasses, or dark brown sugar.

For your recipe I would add 2 tablespoons of lemon juice and 1 tablespoon of dark brown sugar.