Childish excitement aside, the prospect of ice cream is a wonderful thing. I must confess I was more of a sun lolly kid myself- ingeniously designed like a PG pyramid tea bag to prevent kids on a sugar high flipping the contents out onto the floor, that was the problem with Callippos. And as for Mr Freeze? Well, raspberry and cola all the way.
Ice cream isn’t really something I have in my freezer, but that’s because its so chock full of various parts of fish, fur and feather there simply isn’t the room. It just so happened that I had a craving for it during the summer we had a month ago. I decided to google how it was made after having a chat to a friend of mine about hand cranked Ice cream machines and the possibility of involving them down at HGC headquarters.
As I scrolled through endless useless links, the only instructions I could find were how to make it with a couple of plastic bags- nothing on putting together a traditional hand powered beast of a machine: It was time to hit the workshop and get tinkering…
The principle behind making I scream, you scream, we all scream for Ice Cream is both keen and cunning, a process evolved and developed over 100’s of years. It is not exactly clear who is credited with hitting the nail on the head. Most countries have been messing about with their own versions of frozen pud for time, however it was the Arabs that were the first to tuck into the dairy and use milk, sweeten it with sugar, flavour with rose water and fruits & nut. Before that it was all sorbets- in 62AD the Roman emperor Nero used to send slaves up to the Apenine mountains to collect snow to be mixed with honey it has even been claimed, in the Yuan dynasty, Kublai Khan enjoyed ice cream and kept it a royal secret until Marco Polo visited China, pinched the technique and high tailed it back to Italy. Well thank you Wikipedia. I like to maintain a ‘plagiarism free’ blog…
So where to start? Firstly you don’t actually even have to make a contraption, for the simple ‘bag method’ all you need is:
- 1 large ziplock plastic bag
- 1 small ziplock plastic bag
- ½ cup of whole milk
- 2 TBSP caster sugar
- 2 trays of ice cubes.
- 6 TBSP salt.
And follow this link for a video on how to do it. Not to be rude, but this isn’t amateur hour: the ice cream is far from perfect- for that you need a proper hand-cranked, Macgyver issue machine…give me two buckets, a plastic box, a piece of wood and a hand drill.
The science behind making ice cream is the same for both the ‘bag’ method and the ‘pot freezer’ method. This involves mixing salt with ice. In simple terms…bear with me sciences were never my strong point:
Lets say you have a glass of water with crushed ice in, ok? For ice to melt, energy must be drawn in from the surrounding water to break the hydrogen bonds that keep the ice frozen. The energy that's taken is in the form of heat, which is why ice makes the water cold, since it's taking the heat to melt. Salt upsets the balance and makes the melting rate slower, because the ice requires more energy to melt. This draws more heat from the solution, which results in a larger temperature drop.
That took me a long time to understand too. For more info on why check out this link. So a combination of ice and salt will lower the temperature allowing your mixture to become ice cream, water isn’t needed. It took me a couple of failed attempts before I had perfected the machine.