Why does a cake sink

[Astrid]

Just wondering about the addition of vinegar. You have two lots of raising agents there, one in the flour and the other with the bicarb and vinegar. Be very careful with measurements, weighing is better if you can do so for thing like flour.

[jaspen]

thanks for everyones advise - the flour was relatively new (doesn't mean it hadn't been sitting on the shelf at the shops for while given we are in the bush).

MD - this is the first time I can definitely say the oven was well preheated (so often I don't do this when cooking but in this particular instance I did for a change) and didn't open the door.

The house is a rental and we haven't been here too long so maybe it is the oven as this is the second time here with the cake - both times have flopped but the first time I thought it was cause I opened the oven door

It is a very moist mix and I just mixed with a spatula not an electric mixer but because the recipe has said beat for 2 mins at each stage I gave it a good going over with the spatula - maybe too much.

There are a few things there I need to check so plenty of choc cake coming up I think while I test to see what works.

Good tip with the foil thanks Rouge (especially when I'm trying to make a bigger cake cause I've done that before and had the edges over cook while waiting for the centre)

Bath - look forward to reading if you find it Bath cause I've googled and not found too much - they generally focus on the its not cooked and you've taken it out too early scenario.

Anyway thanks again everyone - will update the thread as I go through the testing process.

[Rouge]

Check the seals on the oven because loose seals can cause cakes to sink too.

I know it sounds silly, but test with a few different cheap packet mixes (like the 99c no brand cake mixes) and see how it goes...

[jaspen]

thanks for the tip rouge - will do - i've been making plenty of vanilla cupcakes with no problem - although they probably aren't as suspect to sinking as this bigger denser chocolate cake or even a big cake in general

[Bathsheba]

Ok Delia emphasises using the correct size tin. She says "the wrong size tin can account for %99 of failed cakes" (presumedly due to sinking). She said that it can be hard to get a good tin these days due to lots of dodgy quality ones out there in non-standard sizes. Apparently they try to undercut each other by making their tins fractionally too small. So maybe check that your tin is the right size for the recipe. I got this info from Delia's white "How To Cook (series one)" book. ETA: most of my tins are from my mother... hand-me-downs that she got over 40 years ago whe she was setting up house. I also buy tins from op Shops... so maybe this means I have standard size tins. The only tin i have bought new was an expensive-at-the-time_but-well-worth-it spring-form tin made in Germany by Kaiser... a standard 20cm round one.