Sinking sponge

[siblingrevelry]

I'm a cake maker/decorator by profession, so would class myself as relatively experienced, but have recently had a continued problem I'd like to pick folks' brains about!

When baking a sponge in the oven, the middle doesn;t cook very well, the cake sinks whilst the outside gets darker and crispier. The mixture is the same as always has been (equal quantities of stork/caster sugar/eggs/flour plus 2oz extra for density - creamed method, eggs gradually added and flour folded gently in).

The cakes are usually cooked on low for a long time (gas 2), and until recently have been perfect. As this is a new phenomenon (but happening repeatedly), I can rule out a dodgy batch of something, and as it's a low oven I'd be surprised if it's a temp issue.

Any thoughts?

Thanks in advance

I wonder if your flour supplier has changed something, does sound odd. I'd second an oven problem, try checking oven temperature with thermometer, I've seen very odd fluctuations when an oven thermostat goes wrong. Even more fun, it can be intermittent which is a right bugger to track down! that was my old, not at all missed gas oven . dodgy thermostat on an electric required a conversion chart on wall next to it, and a recheck with a thermometer every year or so.

PS what happens at gas mark 4? do they bake ok (although quicker) at that temperature?

Thanks for the replies.

I'll give gas 4 a try - I bake cupcakes etc at gas 4, and usually don't have an issue (although, interestingly, I have recently experienced the cake case peeling away from the cakes at times, so wonder if the two are connected and it's a temp issue?)

Gas ovens can often be inaccurate at low temperatures. Please see the following which we put on our website:
Oven temperatures Autumn 2007

Baking a Rich Fruit cake (particularly the larger sizes) is a significant investment in both time and ingredients. Concern has recently been raised about the accuracy of some modern ovens when cooking at low temperatures, particularly gas mark 1. Reports suggest that in some cases, a setting of gas mark 1 produces temperatures significantly lower than the correct level of 275°F (140°C). More than one customer has contacted us with tales of large iced cakes being sliced open to reveal uncooked centres!

We recommend that before baking at gas mark 1, you should invest in a good oven thermometer. These typically cost under £5.00 and are available from most cookshops. Though inexpensive, the readings produced are generally more accurate than built-in thermometers. If you do find your oven is inaccurate, simply adjust the temperature using the thermometer as a guide. Remember to allow the temperature to settle before taking a reading.

It's important to remember that the temperature within a gas oven will vary from the top (hottest) to the bottom (the coolest part). Please be sure to temperature test and bake in the same shelf position, or on the middle shelf if no particular position is specified.

Sib, i had the same happen to me on the weekend, did the same mix, same quantities, snae temp, etc etc, the bloody thing sank in front of me while still cooking, i make cake for birthdays, a local cafe, so annoying, heavy greasy, threw it out and had to start again, grrrr.