Old-Fashioned Potato Soup
Every American grandmother had a potato soup, and it never came out of a cookbook. It was what the back of the stove did on a snowy afternoon: potatoes, an onion and a couple of sticks of celery simmered soft in stock, then made rich with whole milk thickened the old way, with a spoonful of flour cooked in butter. No cream, no leeks, nothing fancy — just the quiet, filling sort of bowl that carried families through long winters and lean weeks alike.
Two things separate the real thing from a thin, watery imitation. First, use floury potatoes — Maris Piper, King Edward or russets — because their edges dissolve into the broth as they simmer and do half the thickening for you. Second, part-mash with a masher, never a blender: three or four presses straight into the pot, so about a third of the potatoes melt into creaminess while the rest stay in soft, spoonable chunks. A blender overworks the starch and turns the whole pot gluey.
The last kindness is gentleness: once the milk goes in, never let it boil, or it can catch on the bottom and curdle. Ladle it up plain, the way granny mostly served it, or scatter over crisp bacon and a handful of grated cheddar and watch it disappear.
Old-Fashioned Potato Soup
Creamy but still chunky — floury potatoes in a gentle milk broth, part-mashed the old way. Bacon & cheddar optional.
Ingredients
- 1 kg floury potatoes (Maris Piper or russet), peeled, in 2 cm chunks
- 1 onion and 2 sticks celery, finely chopped
- 750 ml chicken or vegetable stock
- 45 g butter and 25 g (3 tbsp) plain flour
- 500 ml whole milk, warmed
- salt and white pepper
- to finish, optional: 4 rashers crisp bacon, 60 g mature cheddar, chives
Method
- Simmer. Potatoes, onion and celery into a large pot with the stock and ½ tsp salt. Boil, then simmer 12–15 minutes until the potatoes are quite tender.
- Roux. Meanwhile melt the butter in a small saucepan, stir in the flour and cook 1–2 minutes without colouring. Whisk in the warm milk a splash at a time until smooth.
- Marry. Stir the milk sauce into the pot. Gentle heat from here — never let it boil once the milk is in, or it can catch and curdle.
- Part-mash. Three or four presses of a masher straight into the pot — about a third of the potatoes. Creamy, still chunky. Simmer very gently 5 minutes to thicken.
- Season and serve. Salt and white pepper — more than you think. Ladle up and finish with crisp bacon, cheddar and chives, if you like.
It thickens as it stands — loosen tomorrow's bowl with a splash of milk, never water, and reheat it gently. Plenty in this house swear it's better on day two.
Tips for the creamiest pot
Floury potatoes only
Maris Piper, King Edward or russets collapse at the edges and thicken the soup themselves. Waxy salad potatoes stay glassy and it never turns creamy.
Mash, don't blend
Three or four presses of a masher gives body and keeps the chunks. A blender ruptures the starch and turns the pot gluey.
Gentle once milk is in
Keep it below a boil after the milk goes in — hard boiling makes it catch on the bottom and can curdle it.
Questions, answered
What are the best potatoes for old fashioned potato soup?
Floury (starchy) potatoes — Maris Piper, King Edward or russets. Their edges break down as they simmer and thicken the soup naturally, which is exactly what makes it creamy. Waxy salad potatoes such as Charlotte hold their shape too well and leave the soup thin, with firm, glassy chunks.
Why is my potato soup gluey?
Overworked starch, almost always from a blender or food processor — blitzing ruptures the potato starch cells and turns the soup to wallpaper paste. Use a hand masher instead and crush only about a third of the potatoes, stopping as soon as the soup looks creamy. Choosing floury potatoes and mashing gently gives body without the glue.
Why has my potato soup curdled?
It boiled after the milk went in. Milk-based soups split when they boil hard, especially with salty stock or bacon in the pot. Keep the soup at a bare simmer once the milk is added and stir now and then so it does not catch on the bottom. Whole milk is far more stable than semi-skimmed, and the flour in the roux helps protect it too — do not skip it.
Can I freeze potato soup or make it ahead?
It keeps in the fridge for 3 days and reheats gently with a splash of milk. Freezing the finished soup is not ideal — the milk can split and the potatoes turn grainy once thawed. If you want to freeze, stop before the milk stage: freeze the potato and stock base for up to 3 months, then thaw and finish with a fresh roux and milk.