Dal: soft first, sour last
Lentils soften as heat loosens the pectin in their cell walls. Acid fights that. Tomato, tamarind or lemon added too early keeps the walls firm, and the lentils stay stubborn. Cook them soft first, then add the acid.
Skim the foam
A gray foam rises when dal first comes to a simmer. It's lentil protein and starch trapped in bubbles. Skim it early and leave headroom in the pot so it doesn't boil over. Rinsing first removes dust and surface starch.
Test yourself
Questions from the interactive lesson, with the answer and the why.
When should tamarind or lemon juice go into dal?
Once the lentils are fully soft. Acid then adds sourness without slowing the cooking.
True or false: Acid in the pot makes lentils soften faster.
False. Acid keeps legume cell walls firm and slows softening.
What went wrong? You simmer toor dal with tomatoes and lemon juice from the start. An hour later, the lentils are still firm.
The acid went in early and slowed softening. Acid keeps the cell walls firm, so softening stalls.
Fill the blank: Acid strengthens the cell walls of legumes, so adding it early slows their ___.
Acid strengthens the cell walls of legumes, so adding it early slows their softening. Firmer cell walls resist heat, so lentils cook more slowly.
Foam rises when dal first simmers. What is it mostly made of?
Lentil protein and starch trapped in bubbles. Water carries these out of the lentils, and bubbles trap them.
True or false: Adding salt early will not stop lentils from softening.
True. Salt doesn't firm cell walls the way acid does, so seasoning the pot early is fine.
