It's quite easy. A physicist can probably explain better- are there any?- but essentially you need to break up the freezing process by regular mixings, to disrupt the big ice crystals. So you end up with smoove ice cream rather than crunchy old ice.
I made this because I was desperate for a hot fudge sundae like I had on my US holiday. I wish I could tell you it was from some swanky SF ice cream boutique, but it wasn't, it was from Fisherman's Wharf.
Regardless, you can now recreate the experience of reconstituted touristy goo in your own freezer!
(I made blueberry cheesecake flavour. You don't have to.)
Basically this is a frozen custard with added flavouring. You make the custard, add the flavouring, freeze it and every so often take it out and give it a good spoon-bashing.
3 bashings separated by 1-2 hours seems to be sufficient.
1 pint or so of double cream
1 tablespoon of cornflour
16 floz milk
12 floz sugar (I use my floz measuring jug or a cup-measure jug. Quantities don't need to be exact, and you can vary the amount of sugar to taste.)
As I was adding a box of soft cheese, I imagined that was equal to another pint of cream. That probably means, for cheeseless ice cream you should use two pints of cream. You decide whether you want that much cream.
This was mashed up from a couple of separate recipes, so I do not think it matters that much. It'll be less creamy and there will be less of it, but the process should be unaffected.
Dissolve sugar in 'scalded' milk (slightly boiled is what I did.)
Simmer the milk over a low hob, adding cornflour and egg yolks, for about
10 minutes. It will be a thin custard.
Cool until cool.
Add the egg whites and the cream.
Add desired flavouring (could be anything- fruit bits, juice, leaves, who knows.)
If you have an empty ice-cream box, that is just the thing for freezing this in. It will be exactly the right size.
Pour in the custard (with your desired flavouring mixed/swirled in) and freeze it. Set your freezer to 'Extreme Cold' or equivalent.
Check on it every hour or so.
Once it shows signs of freezing at the edges, mix (but not so it melts.)
Repeat a couple more times, or until bedtime.
I left it overnight to freeze after a couple of beatings. It turned out quite smooth, but is not quite soft-scoop... it requires determined chiselling and a bit of leaving out in the sun. More beating may improve this.
Still, it has an ice-free texture, and is certainly ice-cream and not ice.
Blueberry Cheesecake flavouring:
1/2 jar Blueberry jam
Blueberries (these are bloody expensive, so you can substitute all jam)
Sugar to taste
Couple of tbsps of water
Lemon juice, to taste (sets off the blueberries. Not strictly necessary)
I also added coriander and mixed spice powder.
Some digestive biscuits
-Blend all the above in blender or similar, or mash it up in a bowl.
Does not need to be particularly smooth.
You can blend and add the biscuits separately if you wish. It tastes odd to have them all together when it's liquid, but when frozen does not make much difference.
Or you can omit them altogether, and just eat them as biscuits.
1 boxworth of soft cheese
-Add this to the custard once it is cool.
Once both components are ready, swirl them together by layering them in the ice cream box and stirring it a bit. They shouldn't be completely mixed. (Same procedure for Raspberry Ripple.)
You could also use this in a milkshake, by blending it with milk.
Hot Fudge Sauce
3 tbsp. cocoa
Roughly equal amounts of butter and sugar (about 2-4 oz I'd say. This was extrapolated from a US recipe; I don't know how much 'a stick' is.)
3 floz milk
Mix in a jug, then microwave. Mix again. That's all. This is wonderfully sticky and can be refrigerated for repated use.
Should be served hot on your ice cream.
Enjoy the DIY nature of this ice cream, and impress non-Sydtrough goers with tales of how you can easily make it yourself.