Cabbage is massaged with salt for coleslaw because salt draws water out of the cabbage cells; the cabbage softens, shrinks in volume, loses some of its raw sharpness, and does not release water into the bowl later. In coleslaw made without massaging, the cabbage stays firm, the dressing does not cling, and a watery pool collects at the bottom of the bowl within an hour. Drain and squeeze the salted cabbage, then dress it.
Salt works through osmosis. Cabbage cells are full of water; when salt touches the surface, the environment outside becomes more concentrated, and water is drawn out of the cells. Massaging by hand speeds up this process because pressure from your fingers breaks some cell walls and helps the salt penetrate. Within fifteen minutes, a visible amount of water collects beneath the cabbage. The cabbage softens as water comes out but does not lose all its crispness; that is exactly the texture you want in a salad.
First, shred the cabbage finely; thin strips take up salt faster and mix better with the dressing. 5–7 grams of salt is enough for half a kilogram of cabbage. Sprinkle the salt over the cabbage and massage it with 2 hands, squeezing handfuls, for 1 to 2 minutes. Then put the cabbage in a colander and let it sit for 15–30 minutes. During this time, it loses a noticeable part of its volume; a pile that looked large in the bowl becomes much smaller by the end of the wait.
When the wait is over, squeeze the cabbage by hand to remove the water. Taste a small pinch; if it is too salty, rinse the cabbage once with cold water and squeeze it again. If you skip squeezing, the salty water mixes into the salad and dilutes the dressing. Before adding any more salt to the salad at this point, always taste it, because salt remains in the cabbage and the dressed salad is often salted just right. If the salad tastes too salty, the only way to balance it is to add more freshly shredded, unsalted cabbage.
Add the dressing to the squeezed cabbage: lemon juice or apple cider vinegar, olive oil, and grated carrot if desired. Salted cabbage absorbs the dressing much better, and the dressing spreads evenly over every strip. Use the same method for red cabbage; acid turns it a brighter red. Do not salt the carrot; add it directly to the dressing, because salted carrot also releases water and runs its color over the cabbage. After adding the dressing, let the salad sit for at least ten minutes so it penetrates the cabbage and the flavor settles.
Coleslaw made with massaged cabbage does not deteriorate as it sits; instead, it settles in. It keeps the same texture in a sealed container in the refrigerator for 1 to 2 days and does not get watery, while coleslaw made without massaging softens and releases water within a few hours. That is why you can prepare salad for a large gathering 1 day ahead. Add fresh ingredients such as herbs and pomegranate seeds when serving. Stir the salad and taste it once more before serving. Chilled salad tastes a little less salty and sour; a few drops of lemon before serving will freshen it up.