No gas mark ¼ or ½?

If you want to follow a recipe that calls for gas marks ¼ or ½ and do not have these settings on your gas oven, please buy an oven thermometer and test your oven before you start cooking. Oven thermometers are inexpensive and stocked by most cookware shops.

Here are the Fahrenheit and Centigrade equivalents of the old slow or cool oven gas marks.
Gas mark ¼ = approximately 225°F (110°C)
Gas mark ½ = approximately 250°F (120°C)
Gas mark 1 = approximately 275°F (140°C)

To obtain the lowest temperatures you need to be prepared to experiment with moving the oven temperature dial to different positions between the point where the gas comes on and the mark 1 indicator. Try halfway, then use the thermometer to see what temperature your oven gives.

If your oven comes with an S (meaning slow) or E (for economy) mark on the dial, this setting may give you a temperature in the region of the old gas mark ¼, but we have found annoying variations between manufacturers and models and therefore again recommend buying an oven thermometer and checking that this setting really does give a reading in the region of 225°F (110°C). If you have an S or E mark equivalent to gas mark ¼, moving the oven dial half way between S or E and gas mark 1 should bring you close to the gas mark ½ temperature. (One fine day gas oven manufacturers will work out that a built-in thermometer would be very helpful.)

It's also important to remember that the heat within a gas oven will vary from the top (hottest) to the bottom (the coolest part), so place the thermometer on the shelf position Delia states in the recipe you are going to cook, or on the middle shelf if no particular position is specified.

Conversion tables

Cooking at gas mark 1

we've had some worrying reports of under-cooking at gas mark 1. Our investigations suggest that in some ovens – modern ovens, particularly – gas mark 1 is nto what it used to be, ie 275°F (140°C).

Before you start a recipe requiring gas mark 1, please buy an oven thermometer and check the temperature your oven gives on gas mark 1. This is especially important when you are going to the trouble and expense of making Christmas cakes and similar rich fruit cakes! An oven thermometer is an inexpensive piece of equipment stocked by most cookware shops that will ensure you are cooking recipes at the temperature they were tested at.

If you find that your gas mark 1 setting is a bit too cool, move the dial halfway to gas mark 2 and test the oven again. If the oven is too hot, adjust the dial a couple of degrees in the other (cooler) direction.

It's also important to remember that the heat within a gas oven will vary from the top (hottest) to the bottom (the coolest part) so place the thermometer on the shelf position Delia says in the recipe you're going to cook, or on the middle shelf if no particular position is specified.