How much potato salad for 20 people
Short answer
4 kg (9 lb) of potatoes for 20 people, which makes about 5 kg of finished salad once dressed — 200 g a head. Use a waxy potato, and make it the day before.
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Potatoes
4.0 kg (8.8 lb)
Medium potatoes (about 170 g each)
24
Butter and cream, if mashing
400 g + 480 ml
Salt for the water
40 g
Two hundred grams a head is the right number for a side dish sitting alongside three or four others, and people eat less potato salad than they expect to. Where it goes wrong is in the other direction: a bowl made for twenty at 300 g a head is a bowl you are eating for three days.
Buy a waxy potato, not a floury one. New potatoes, fingerlings or red-skinned varieties hold their shape through boiling, cooling and stirring. A russet or a Yukon Gold falls apart at the second stir and gives you mashed potato with a dressing on it — which is a fine thing, but it is not what anyone came for.
Dress them warm. A warm potato absorbs vinegar and oil; a cold one lets the dressing sit on the outside and slide off. Toss the drained potatoes with the vinegar first, let them sit five minutes, then add the mayonnaise once they have cooled — mayonnaise splits on hot potatoes.
Make it a day ahead and it improves; make it three hours ahead and it does not. Potato salad needs a night for the seasoning to move through, and it also frees your fridge and your hands on the day. What it does not tolerate is sitting out — keep it cold until it goes on the table, and take back what has been out over two hours.
Related questions
How many potatoes is 4 kg?
About 24 medium potatoes at 170 g each, or a standard 5 kg bag minus a few. Buy the bag; a spare potato is not a problem.
How much dressing for 4 kg of potatoes?
About 700 ml total — roughly 500 ml of mayonnaise, 100 ml of vinegar or pickle brine, and 100 ml of mustard and seasonings. Add half at first and judge the rest cold.
How long can potato salad sit out?
Two hours, one if it is above 32°C (90°F). Serve it from a bowl set in ice and refill from the fridge rather than putting the whole batch out at once.