- 397g tin of sweetened condensed milk. Don't confuse this with evaporated milk.
- 200ml milk
- 1kg sugar
- A piece of butter around the size of a walnut
Put sugar in pot and pour in condensed milk, milk and stir well. Drop in the butter. Cook over low heat until bubbling up. This may take up to 10 minutes or more, depending on the heat.
When it's bubbling, the level of the mixture will rise by at least 1/3, so make sure you are using a reasonably deep pot. Try and keep the level of the bubbles consistent, and stir occasionally to prevent sugar building at the bottom. Keep an eye on it because you do not want it to bubble over. That leaves a horrible mess and may destroy your hob...
Cook for approximately 40 minutes, but test by dropping a wee spoonful into a plate of cold water. When ready it will form into small firm-ish balls. If it is not ready it runs throughout the water not sticking together. The colour of the mixture in the pot should change from pallid white to brown as well.
While it's cooking, prepare a tray for it to set in. I used a baking tray which was about 2cm deep, 20cm wide and 30cm long, and this seemed just the right size for this quantity. The tray can either be greased with a little butter, or line it with parchment paper.
When it's ready, take it off the heat and whisk (using an electric whisk) in the pot until it is thick and the ripples stay up rather than disappear. You will find some of the tablet sticking to the side of the pot as it gets closer to being ready. Pour into your prepared tray and leave it to set at room temperature.
When partially set, take a sharp knife and score the top of the tablet into a grid of the size of pieces you want to break it into.