Before and during cooking

Stop preparing oversize portions

If you are regularly throwing food away, avoid buying, preparing and serving food in volumes that make over size portions which no-one can finish.

Defrost food before cooking

​Defrost your food (either in the microwave or just by taking out of the freezer the day before use) prior to cooking and you can halve the cooking time, saving money on your energy bills.

Defrost food before cooking and halve cooking time.

Wash vegetables in a bowl rather than under a running tap

Use a bowl when preparing your vegetables instead of washing them under a running tap and you can save about 5 litres of water each time. And after washing the veggies why not recycle the water by watering plants around your home or in the garden?

Par boil potatoes before roasting

Partly cook potatoes by boiling them before roasting. By doing so you’ll reduce the amount of time they take to roast in the oven.

Try to cook only what is needed for a meal

It is so easy to overestimate portion size. Count out each part of the meal e.g. how many potatoes does each person need, a 6’8” rugby player probably needs more than your nan! If you are not happy to trust yourself take out the guesswork with the portion tool at

Bulk cooking

Alternatively, bulk cooking is a more efficient use of appliance energy and your time, so cook up a nice big meal and then freeze or refrigerate extra portions for eating at a later date.

Cook food in bulk, then freeze or refrigerate for later use.

Turn oven off before end of cooking time

​Reduce energy costs when cooking by turning your oven off before the end of the cooking time. Provided you don’t open the door, it will stay at the same temperature for 10 minutes.  You could save 5p every time you use your oven, about £10 per year, equivalent to 35kg of CO₂.

Use a slow cooker

​Cooking a stew in a 2kWh oven for 1 hour costs around 28p. Cooking the same stew in a slow cooker for 8 hours will use 0.7kWh, costing around 10p. Based on using a slow cooker twice a week – the savings per year would be about £19, equivalent to 64kg of CO₂.

Using a slow cooker can save around 65% in electricity cost compared to an oven.

Choose the right size of ring or burner for the pan

On an electric stove, a 15cm pot used on a 20cm ring wastes more than 40% of the rings heat. This costs you an extra 13p per hour, which if you cooked on the wrong sized ring for 2 hours per week, adds up to £14 per year, equivalent to 47kg of CO₂.

Keep the oven closed while you’re cooking

If you open the door when cooking, the oven loses up to 20% of its heat and requires more energy to return to its original cooking temperature. Also, try to keep the oven door clean so you can look in to check your food rather than having to open it.

Use the fan assisted cooking option

Most electric cookers are fan-assisted which helps them to evenly spread heat round the oven. This means that cooking temperatures are reduced and cooking times are speeded up.

Use the fan assisted option whenever possible to reduce cooking time and save energy.

If buying new, buy an A+ rated oven

​Cookers are becoming more efficient. We recommend ovens that have an ‘A’ energy rating as they are the most efficient of all; hobs that carry the logo are highly energy-efficient too. A new A+ rated electric oven will consume 40 per cent less energy than a B rated oven.

Put lids on pans

Always use the correct size pan for the ring or burner you are cooking on to save energy. Put lids on pans to keep the heat in, and make sure the lids are close fitting.

Simmer food rather than boiling it

Turn down the ring or burner once cooking temperature or state is reached, then simmer until food is cooked.

Cut food into smaller pieces before cooking

That way it will cook more quickly and save energy.

Cut food into smaller pieces so it will cook more quickly and save energy.