Why is my soup gritty?
Grit in a soup is either actual grit from the vegetables, fibre that the blender could not break down, or curdled dairy — and each one has a different answer.
- Difficulty
- beginner
- Time
- 12 min
- Read
- 4 min
Short answer
Fine sandy grit is soil from leeks, spinach or mushrooms that was not washed out. A fibrous graininess is under-blending or fibrous vegetables such as celery, asparagus or old parsnip. A milky graininess is split dairy. Only the first is preventable after the fact — the second needs a sieve.
Three quite different textures get described as gritty, and it is worth deciding which one you have before doing anything. One is a washing problem, one is a blending problem, and one is a dairy problem. The fix for each is straightforward once identified, and a fine sieve solves two of the three.
Step by step
- Taste and feel it against the roof of your mouth.Hard, sandy, slightly crunching: soil. Soft but stringy or fibrous, catching on the tongue: vegetable fibre. Fine and slightly curdled with a milky look: split dairy.
- For soil, pass the soup through a fine sieve and let it settle.Grit sinks. Ladle the soup through a fine sieve into a clean pan and leave the last inch behind. Some will still be suspended, so let the pan stand for a few minutes and pour off the top.
- Wash the culprits properly next time.Leeks hold soil between the layers — split them lengthways and fan them under running water. Spinach and chard need two or three changes of water in a bowl, lifting the leaves out rather than draining. Mushrooms should be brushed or wiped. Loose-soil vegetables such as celeriac and beetroot need scrubbing.
- For fibre, blend for longer and then sieve.Most home blenders need a full minute, not fifteen seconds, and a jug blender gets smoother than a stick. After blending, pushing the soup through a fine sieve with the back of a ladle removes what remains and makes an enormous difference to a celeriac, asparagus or parsnip soup.
- Cook fibrous vegetables until genuinely soft before blending.Under-cooked vegetables do not blend smooth however long the machine runs. Celery strings, asparagus stalks, old parsnip cores and squash skin all stay as fibres. Peel where necessary and give them the extra ten minutes.
- For curdled dairy, blend and stabilise.A stick blender disperses the grains. A teaspoon of cornflour slurry warmed through helps hold it together. Next time, use double cream rather than single, and add it off the heat.
- Add fat at the end to improve the mouthfeel either way.A knob of butter, a swirl of cream or a spoonful of olive oil blitzed in coats the palate and makes a slightly imperfect texture read as smooth. It is the standard restaurant finish and it works.
Tips
- A fine chinois or a conical strainer is the single most effective piece of kit for smooth soup, but an ordinary fine sieve and the back of a ladle gets most of the way.
- Blend hot soup in small batches with the lid vented and a cloth over the top, or use a stick blender in the pan. A sealed blender of hot liquid can blow its lid off.
- Peel parsnips and celeriac generously and cut out the woody core of an old parsnip. Both are common sources of fibre in an otherwise smooth soup.
- Squash and pumpkin skins do not blend. Roast and scoop, or peel before cooking.
- A potato in a fibrous soup adds body that masks minor texture faults — but do not over-blend it, or the soup goes gluey instead.
If it doesn't work
Sandy grit that crunches
Cause: Soil from leeks, spinach, mushrooms or root vegetables — Fix: Sieve and settle the soup. Wash the vegetables properly next time — leeks split lengthways, leaves in a bowl of water lifted out rather than poured off.
Fibrous and stringy after blending
Cause: Fibrous vegetables, or under-blending — Fix: Blend for a full minute in a jug blender, then push through a fine sieve.
Fine milky graininess
Cause: Dairy curdled from boiling or acidity — Fix: Blitz with a stick blender and warm in a teaspoon of cornflour slurry. Use double cream off the heat next time.
Slightly gritty tomato or pepper soup
Cause: Skins and seeds broken into fragments rather than pulverised — Fix: Sieve it. For a truly smooth result, skin and deseed peppers and tomatoes before cooking.
Grainy after adding pulses
Cause: Lentils or chickpeas under-cooked, so their skins and centres do not break down — Fix: Simmer for longer until they collapse, then blend. Under-cooked pulses never blend smooth.
Questions people ask
Will a more powerful blender fix a gritty soup?
It will fix the fibre kind, largely — a high-powered jug blender pulverises celery strings and squash fibre that a stick blender cannot. It will not fix soil, because grit is mineral and simply becomes finer grit. And it makes potato-based soups worse, because over-blending potato bursts the starch cells and turns the soup gluey.
How do I get leeks properly clean?
Trim the root, split the leek lengthways from about halfway down, and fan the layers apart under a running tap, working from the base upwards. Soil sits between the layers, particularly near the green end, and rinsing a whole leek does nothing at all. If they are already sliced, swirl them in a bowl of water and lift them out with your hands, leaving the grit behind.