At the weekend, I made millionaire shortbread according to the recipe in Nigella Lawson's "How To Be a Domestic Goddess" (the full recipe is below for completeness). For the caramel part, Nigella uses a microwave and the instructions are as follows:
397g sweetened condensed milk
4 tbps (100g) golden syrup
Melt 200g of butter in the microwave (in a large microwavable bowl) for 2-3 minutes, then add the condensed milk and golden syrup. Whisk the mixture well until the butter is thoroughly incorporated. Heat for 6-7 minutes until it is boiling, stirring thoroughly every minute. [...] It's ready when it's thickened and turned a light golden-brown.
Now the result of this is delicious, but it is far too soft for millionaire's shortbread, and it squishes out the sides when trying to eat or cut. My partner has also made this recipe with the same results.
I don't really understand the science of caramel, so I'm not sure what to change to get the results I want. So I have a few questions:
- What can I change? Is there something in the above recipe I can do more of, do less of, add more of, etc.?
- The answer to this question suggests that the above ingredients are more reliable (than standard caramel) for getting the right texture, but the linked recipe does not use the microwave. Might I get better results without the microwave?
- In Nigella's foreword, she advocates the use of the microwave as "what would normally take a good couple of hours takes only a few minutes". Caramel does not take a couple of hours, does it? What is she talking about?