Cooking Efficiently With Lids, Batches and Right-Sized Pans

Where cooking energy goes

Cooking is usually a modest part of a household’s energy use compared with heating, hot water and, in many homes, laundry. That is useful context: efficient cooking is worth doing, especially because you do it every day and it often saves money, but it rarely changes a home’s overall footprint as much as other choices. The exact balance depends on your appliances, your local energy supply and how much you cook from scratch.

Most savings come from the same idea: put heat into the food, not into the room or the air. The habits below are ordered roughly by how much difference they tend to make, though the exact amounts vary from kitchen to kitchen.

Use a lid

A lid keeps heat and steam in the pan. Water comes to the boil sooner, and once it is boiling, a lid helps it stay there at a lower setting. For anything you are simmering, boiling, steaming or reheating, a lid is probably the simplest habit and one of the most effective. It also reduces condensation in the kitchen.

Once a pot reaches a boil, turn the heat down. A rolling boil is not hotter than a gentle one, since water at normal pressure cannot get hotter than its boiling point; extra heat mainly turns more water to steam. A steady simmer cooks pasta, potatoes and pulses just as well, and uses less fuel.

Match the pan to the food and the ring

A pan that is much smaller than the ring lets heat spill around the sides, and a pan that is much larger than the food takes longer to heat. A good rule is to pick a pan close to the amount of food you are cooking, and a ring or burner about the same size as the base of the pan. Flat-bottomed pans that sit fully on an electric or induction hob transfer heat more effectively than warped ones.

Using less water also helps. Vegetables usually need only enough water to just cover them, or even a small amount for steaming, and less water heats faster. Do not go too far, though: pasta and rice need enough water to cook properly, and a dry pan can burn.

Pick the right method for the job

Different appliances suit different tasks:

• A kettle is generally an efficient way to heat water. Boil only what you need, while staying above the kettle’s minimum fill level. Pouring boiled water into a pan can be quicker than heating it from cold on the hob.
• Microwaves are often efficient for small portions, because they heat the food directly. They are less useful for browning or large dishes.
• Pressure cookers shorten cooking times for foods such as stews and dried pulses, which generally reduces the energy used. Follow the manufacturer’s instructions for safety.
• Slow cookers use a low power for a long time, so they are not always lower in total energy than other methods, but they are generally economical for what they do.
• Induction hobs heat the pan directly and tend to waste less heat than many gas or older electric hobs, but this is no reason to replace a working hob. Buying new appliances has its own manufacturing impact, so replacing an item that still works is rarely the greenest choice.

If you are choosing a new oven or hob anyway, learning to read energy labels helps compare models, and the broader question of household appliances covers how to weigh replacement against repair.

Make the most of the oven

Ovens use a lot of energy to reach temperature and lose heat whenever the door opens. A few habits help:

• Cook several items at once if the dishes need similar temperatures, rather than heating the oven for a single tray.
• Avoid preheating for longer than needed. Many recipes, such as casseroles and roast vegetables, do not need a fully heated oven.
• Check through the glass instead of opening the door.
• Use a smaller appliance, such as a toaster oven, air fryer or microwave, for small portions, if you already have one. This is often more economical than heating a full-sized oven, though results vary with the model.
• Turn the oven off a little before the end of cooking for dishes that tolerate residual heat. Take care with food safety, as meat must still reach a safe temperature.

Cooking in batches

Batch cooking means making a larger quantity once and eating it across several meals. It tends to save fuel because you heat the pan or oven once instead of several times. It also saves time and can make healthy meals easier on busy days.

Some points to keep in mind:

• Batches only help if the food gets eaten. A large pot that is thrown out is a net loss in both energy and food.
• Cool leftovers quickly and put them in the fridge within about two hours, or freeze portions promptly. Follow your local food safety guidance on how long cooked food keeps, which is typically a few days in the fridge.
• Reheat until piping hot all the way through. Reheating rice needs particular care, so it should be cooled fast and stored cold.
• A very full freezer is efficient, but a crammed fridge may not circulate air well; see the basics of fridge efficiency.

Batching also fits well with meal planning, since you can decide in advance which meals will share a cooking session.

Which tips matter more

It is tempting to treat every tip as equally important. A rough ranking might look like this:

1. Cooking food that will be eaten rather than wasted. The energy and resources behind the food usually outweigh the fuel used to cook it, so food waste is often the bigger issue.
2. Using lids, simmering instead of boiling hard, and heating only the water you need.
3. Choosing the right appliance and size for the portion.
4. Batching and combining oven use.
5. Smaller refinements such as turning the hob off slightly early.

Hob and oven habits can reduce your energy use, but they rarely amount to a large reduction on their own. If lowering your bills or footprint is the priority, it is also worth looking at home energy use as a whole. Do not sacrifice safe, properly cooked food to save a little energy. Undercooked poultry, pulses or reheated leftovers are far more costly in other ways.