To make vegetable stock, simmer a mirepoix base of onion, carrot and celery in cold water for 45 to 60 minutes, then strain. Keep the simmer gentle, season lightly or not at all, and never boil hard or cook it longer, as that turns the vegetables bitter. Skip brassicas like cabbage and broccoli, which turn a stock sulphurous.
There is nothing to buy in a carton here. Vegetable stock is just water, a few honest vegetables, and a bit of patience on the hob. Your granny made it from the peelings and ends she would otherwise have binned, and it is the quiet backbone of half the soups and stews you love. Get the base right, keep the simmer gentle, and mind the couple of things you must never put in the pot. That is the whole job.
| Stock | Broth | |
|---|---|---|
| Made from | Bones (simmered long) | Meat, sometimes with bones |
| Body | Richer in gelatin, sets to a wobble when cold | Lighter in body, does not gel |
| Seasoning | Usually unseasoned | Often lightly seasoned to sip |
| Vegetable version | No bones, so never gels; simmer only 45-60 min | Same as vegetable stock in everyday use |
The mirepoix base (and what to add)
Every good vegetable stock starts with a mirepoix: the classic trio of onion, carrot and celery. A rough rule is two parts onion to one part carrot to one part celery by weight, but do not fuss over it. Chop everything into big chunks. Small pieces give you nothing extra and make straining a chore.
From there, build flavour with aromatics: a couple of garlic cloves (skins on is fine), a bay leaf, a few peppercorns, a handful of parsley stalks, and a sprig of thyme. Leek tops, mushroom stalks, tomato and fennel trimmings all pull their weight. Softer, sweeter vegetables like a little squash or a wedge of tomato deepen the colour and body. Start it all in COLD water, bring it up slowly, then hold it at a bare simmer.
What to NEVER add
This is where most homemade stock goes wrong, so learn the short blacklist.
Brassicas: no cabbage, no broccoli, no cauliflower, no Brussels sprouts. They turn a stock sulphurous and eggy, and there is no fixing it once it happens.
Too much starch: go easy on potato and other starchy veg. A little is fine, but too much clouds the stock and turns it gluey rather than clean.
Anything past its best: mouldy or slimy scraps make a bitter, off-tasting stock. Wilted and slightly tired is grand; rotten is not.
And a note on time and heat, because they matter as much as ingredients. Never simmer vegetable stock longer than about an hour. Unlike a bone stock, there is no gelatin to draw out, and long boiling only turns the vegetables bitter. Keep it at a gentle simmer, never a hard rolling boil, which makes any stock cloudy and greasy.
Method: step by step
1. Roughly chop your mirepoix (onion, carrot, celery) into big chunks. No need to peel the onion, a bit of skin adds colour.
2. Put everything in a large pot: mirepoix, aromatics, and any clean scraps. Cover with COLD water by a couple of centimetres.
3. Bring up slowly to a gentle simmer. As it heats, skim off any scum and froth that rises to the top.
4. Simmer gently, uncovered or part-covered, for 45 to 60 minutes. Do not let it boil hard, and do not go over the hour.
5. Strain through a sieve into a clean bowl or jug. Press the vegetables lightly to get the last of the liquid, then discard the spent veg.
6. Cool it quickly, then keep in the fridge for up to 4 to 5 days, or freeze for months. Leaving it unseasoned keeps it flexible for whatever you cook next.
The scrap-bag freezer tip
Here is the thrifty trick that makes stock nearly free. Keep a zip-lock bag or tub in the freezer and, as you cook through the week, toss in the clean off-cuts: onion ends and skins, carrot peelings, celery tops and bottoms, leek tops, herb stalks, mushroom stems, the odd tomato end.
When the bag is full, tip the lot straight into a pot from frozen, cover with cold water, add a bay leaf and a few peppercorns, and simmer 45 to 60 minutes. That is a whole batch of stock from what most people throw away.
Just keep the blacklist in mind even for the scrap bag: no brassica trimmings (cabbage cores, broccoli stalks), go light on potato peelings, and nothing rotten. A tired carrot is welcome. A slimy one is not.
Is soup stock the same as vegetable stock?
Yes. "Soup stock" is just the everyday name for the same thing: the strained, savoury liquid you build a soup or stew on. When a recipe calls for soup stock, you can make vegetable stock exactly as above and use it cup for cup.
The method is identical whether you call it soup stock, vegetable stock or vegetable broth (more on that naming below). Mirepoix base, cold-water start, gentle 45 to 60 minute simmer, strain. The only real choice is whether to season it. For a stock you will cook with later, leave it unseasoned so you stay in control of the salt. For something you want to sip on its own, season it lightly at the end.
Questions we get asked
What is the difference between vegetable stock and vegetable broth?
In shops the two words are used interchangeably. The traditional difference is that stock is simmered from bones (so it is richer in gelatin, sets to a wobble when cold, and is usually unseasoned), while broth is simmered from meat, is lighter in body, and is often lightly seasoned to sip. Vegetable stock has no bones at all, so it never gels, whichever name is on the label.
How long should you simmer vegetable stock?
Just 45 to 60 minutes at a gentle simmer. Unlike a bone stock, there is no gelatin to draw out, so there is nothing to gain from longer cooking. Boil it hard or go past the hour and the vegetables turn the stock bitter.
What vegetables should you never put in stock?
Never use brassicas, that is cabbage, broccoli, cauliflower and Brussels sprouts, because they turn the stock sulphurous and eggy. Go easy on starchy veg like potato too, as too much clouds the stock. And never use anything rotten or mouldy, which makes it bitter.
Do you need to peel the vegetables for stock?
No. Peels and skins are welcome, in fact onion skins add colour and clean carrot peelings are perfect for the scrap bag. Just give everything a good wash first, and chop into big chunks so the stock strains easily.
Should you start stock in cold or hot water?
Always start with COLD water and bring it up slowly. This draws out more flavour and keeps the stock clear. Skim off any scum as it heats, and hold it at a gentle simmer rather than a hard boil, which would make it cloudy and greasy.
How do you store homemade vegetable stock?
Cool it quickly, then keep it in the fridge for 4 to 5 days or freeze it for months. Leave it unseasoned so it stays flexible for whatever you cook next. Freezing it in an ice-cube tray gives you handy small portions for gravies and pan sauces.