As a material begins to freeze ice crystals start to grow. If we imagine that these crystals grow at the same rate, the longer they grow for the bigger they become.
Apply this principle to ice cream and we find that to have smooth creamy ice cream we need to freeze the mixture quickly. There is no better, or quicker way to rapidly make ice cream than with liquid nitrogen! In fact the world record for making the quickest ice cream is now less than 10 seconds.
Simply mix 1 pint of double cream and 1 (397g) tin of condensed milk together in a large plastic bowl (don't use a metal one as the mixture tends to end up lumpy! - polypropylene seems the most robust). Add flavouring if required. Then add some liquid nitrogen and stir thoroughly with a wooden spoon. The stiring also helps to break up any crystals which form. Serve into ice cream cones. If mixture melts, it can easily be re-frozen by adding a little more liquid nitrogen.
Take 1 litre of custard (from a carton), add 1 pint of cream, 250g of icing sugar and your flavouring. Mix and serve as above.
The ice cream can also be flavoured before adding liquid nitrogen. Here are a few I have tried which work well:
mashed fruit (raspberries, strawberries or banana are great)
cocoa powder and stilton
apple sauce and cinnamon
crunchy nut cornflakes
Click on the picture above to open a YouTube video of making raspberry flavour liquid nitrogen ice cream. Sorry no sound.
© 2016 Dr Matthew French All rights reserved.