Cookery Know-how · Boiling
Methods of Boiling
Boiling looks simple, but good results depend on preparation, timing and control of the heat. Choose the right starting temperature, then watch the food as well as the clock.
What is boiling?
Boiling is cooking food in a liquid at boiling point. Water boils at about 100°C at sea level, with rapid bubbles and vigorous movement. Simmering is gentler: the liquid is just below boiling point, with small bubbles and gentle surface movement.
Many dishes traditionally called “boiled” are actually simmered for much of their cooking. Soups, sauces, meat dishes such as boiled ham and vegetables all depend on choosing the right heat. Eggs need careful timing, whether you want a lightly cooked breakfast egg, an œuf mollet with a soft yolk, or a cold hard-boiled egg, as in Welsh nutty eggs.
The cooking liquid may be water, stock, a blanc (water with lemon and flour), court bouillon or milk.
Cold or hot start?
1. Start in cold liquid
Place the food in cold liquid, then bring it up to the heat required by the recipe. Stock is a familiar example (see brown stock); potatoes also benefit from a cold start for more even cooking.
Putting food into a cold pan avoids lowering it into boiling water, although the pan still needs careful handling as it heats. Slow moist cooking helps tenderise fibrous foods and extract flavour. Gentle simmering, rather than the cold start alone, helps food keep its shape and avoids churning impurities into a stock.
2. Start in boiling liquid
Bring the liquid to the boil before adding the food carefully. Pasta and leafy green vegetables such as cabbage are familiar examples.
Quick cooking helps retain the colour of green vegetables. Blanching also inactivates enzymes; avoid prolonged cooking if you want a good texture.
Try it: sort stock, potatoes, leafy vegetables and pasta into the two methods above, then identify six more foods and explain your choice.
Keywords
- Simmering
- Cooking just below boiling point, with gentle bubbling rather than a rolling boil.
- Blanching
- Briefly cooking food in boiling water, for example green vegetables such as French beans, often as a preparation for a later cooking stage.
- Refreshing
- Cooling food after blanching or boiling by plunging it into cold or iced water, or running it under cold water. This stops further cooking; drain it once cool.
- Blanc
- A cooking liquid containing water, lemon juice and flour, used for pale, delicate ingredients to help prevent discolouration. Control the heat separately to avoid breaking up the food.
- Al dente
- Italian for “to the tooth”: tender but still firm to the bite, usually used of pasta, as in cacio e pepe.
Procedures of boiling
- Choose and check the equipment
Use a clean, undamaged pan of the right size and type. Leave room for stirring and prevent boiling over. Avoid unnecessary water when cooking vegetables, while using enough for the chosen method.
- Prepare the ingredients
Collect the correct quantities and prepare them before cooking.
- Check the heat source
Have the hob ready and use the heat setting appropriate to the pan and recipe.
- Measure the liquid
Use sufficient liquid for the food and method. Pasta needs room to move; rice can be cooked in excess water or by absorption with a measured amount. Follow the recipe for eggs rather than assuming every food needs a large pan of water.
- Choose the starting temperature and time
Decide whether to start in cold or hot liquid. Follow the recipe’s timing, including time per kilogram where appropriate; size and the food itself matter too.
- Season and thicken where needed
For a roux, melt the fat and add the flour before adding the liquid. Add a bouquet garni, salt and pepper, or a suitable thickening agent as the dish requires.
- Control the temperature
Reduce to a simmer where required and do not let the pan dry out.
- Skim as appropriate
Remove impurities and excess fat from the surface when the recipe calls for it.
- Cook evenly
Watch for sticking or burning and stir where appropriate. Avoid rough stirring of delicate foods.
- Finish promptly
Remove the food when cooked or blanched. Refresh where appropriate, then drain. Serve, or hold at the appropriate safe temperature for service.
Equipment, cleaning and maintenance
Choose the equipment to suit the quantity and the food:
- Stockpots and saucepans
- Boiling pans, directly or indirectly heated
- Bratt pans
- Induction-compatible pans on an induction hob
- Steam-jacketed kettles or boilers
Cleaning: wash saucepans and rinse thoroughly. Switch off steam-jacketed kettles, bratt pans and free-standing stockpots and allow them to cool before cleaning with a suitable mild detergent solution. Follow the equipment manufacturer’s cleaning instructions.
Maintenance: check regularly for cracks and arrange lubrication of tilting mechanisms and counterbalanced lids as specified by the manufacturer.
Test your knowledge
Define each term and give four examples of foods or dishes for which it is appropriate:
- Soaking
- Blanching
- Skimming
- Refreshing
- Draining
- Holding for service
- Batch cooking
Why turn down to a simmer?
Where the recipe calls for it, simmering after bringing to the boil reduces evaporation, limits shrinkage, gives gentler, more even cooking and helps prevent food breaking up. A rolling boil is not the right finishing heat for every dish.
Thickening agents
These belong to the wider work of making soups, sauces and puddings. Not every thickener should be boiled: use the method appropriate to the ingredient.
- Cornflour
- Made from maize. Mix with a little cold water before adding to a hot liquid or sauce, then cook out to remove the raw taste.
- Arrowroot
- A thickener with little flavour, used in preparations such as jus lié. Follow the recipe rather than substituting spoon for spoon for cornflour.
- Tapioca
- Available in forms including pearls, used to thicken sweet puddings.
- Wheat flour
- Plain flour forms a roux with fat, the base of béchamel and velouté. Add the liquid gradually and cook out the floury taste. Dispersing the flour in fat helps prevent lumps.
- Semolina
- A coarse milled grain, commonly wheat, used in sweet dishes; rice and maize preparations are also found.
- Vegetable or fruit purée
- Can give body to a soup or sauce.
- Egg yolks
- Used in warm sauces such as hollandaise and béarnaise, cold sauces such as mayonnaise, and custard sauces. These are not all boiled sauces: egg proteins can curdle when overheated.
- Beurre manié
- Equal quantities of butter and flour kneaded into a smooth paste and added to a hot liquid to thicken it, including fish sauces.
- Blood
- A traditional thickener in dishes such as jugged hare; follow a suitable recipe.
Related recipes
Vegetables and potatoes
- Boiled potatoes
- New potatoes with mint
- Mashed potatoes
- Cabbage
- French beans with pine nuts
- Mushy peas
- Petits pois à la flamande
- Brussels sprouts with bacon
Pasta and rice
- Fresh egg pasta
- Spaghetti carbonara
- Cacio e pepe
- Orecchiette with broccoli
- Potato gnocchi
- Pilaff rice
- Basmati rice pilaf
Meat
Eggs
Sauces
Guides
Sources and further reading
- Professional Cooking: basic principles of cooking and food science — boiling, simmering, moist heat and thickening.
- The Culinary Pro: vegetable cooking methods — potatoes, green vegetables, blanching, refreshing and al dente.
- Good Food: how to cook perfect rice — absorption and excess-water methods.
- Top Chef University: boiling and steaming root vegetables — cold-start potatoes and gentle simmering.
- Chef Simon: les blancs de cuisson — the purpose of a blanc.
See also
The eight methods of cookery, on the Know How index: