How do you stop banana flower soup from tasting astringent?
If the banana flower was astringent it is because of the flower, not the cooking method.

When the flowers are large and young they taste a lot better. If you wait until the bananas are formed and the stem to the flower is long then it will be astringent. The best time to pick the flower is when the stem is 10cm or less from the banana bunch. If the flower is old it will not be as good. 

The variety of banana will also influence the taste of the flower. Sugar bananas often have the best flowers. You can eat the pink section but it is not as pleasant as the white section. If you eat the small individual flowers you need to take out the sepal in the centre which is incredibly time consuming.

Putting the banana flower in lime water is simply to stop it from going brown before you cook it. It does not significantly change the flavour.

There are many ways to cook banana flower. Here is my preferred method:


Peel the flower until you come to the white centre.
Discard the red outer section and the individual flowers hidden within this. 
I like to quarter the centre and then I place in boiling water and simmer for 15 minutes with some salt.


For me it is delicious just like this with some lime, but from here you can put it in a cooked curry, salad, etc.