Overview
First of all it's necessary to distinguish between the two.- Sorbet: this is a frozen preparation made with sugar syrup, and usually fruit purée (or juice).
- Ice cream: this is a frozen preparation made with egg yolks, cream and milk, cooked and flavoured (basically a custard or crème anglaise with added cream).
Classic examples:
 Pear sorbet |  Vanilla ice-cream |
After preparation both are churned in an ice-cream maker.
Sorbets
Sorbet recipes are very simple: you need 50% sugar syrup and 50% fruit purée (this may vary according to type of fruit).Simple to prepare because all the quality comes from the quality of fruit used: the better the fruit is, the better your sorbet will be. In others words, if you use tasteless fruits, you will have a tasteless sorbet. But if you use quality full-flavoured fruit (organic if possible) you will produce a delicious sorbet. An example: if you make a strawberry sorbet using well-flavoured strawberries in season (like "garriguettes" or "Mara des bois") your sorbet will be far better than if you use strawberries bought in February or March in a supermarket.
To make this famous strawberry sorbet, quickly clean strawberries, remove stalk and blend until reduced to a purée, add the same volume of sugar syrup. It's ready to go into the ice-cream maker.
It's also possible to make savoury sorbets, like tomato sorbet for example. The trick is to add an egg white to replace the syrup.
Ice cream
Not quite as easy because there are more ingredients and the mixture needs to be cooked. See mint ice-cream recipe and others in the desserts list.Churning
This is the process of freezing in an ice-cream machine which churns the mixture to make sorbet or ice-cream. Usually there is nothing special to do, but here are some tips:The choice of ice-cream machine is of vital importance
- If you have an old-style machine that has to be put in the freezer with the electric lead passing around the freezer door, drop it, it's too old and inefficient.
- You need as a minimum requirement, a "cold-accumulator" kind, which has a part that is kept in the freezer for 36 hours to "stock up" enough cold to make your ice-cream. This cold container is then filled with the mixture, and a motor turns two plastic blades which scrape all around the edge where it freezes. Here is the model we have at home, making a vanilla ice-cream:
The very best: cold-producing
This kind of machine has its own refrigeration unit, there's no need to put it in the freezer before use, it freezes evenly and can be used whenever required. Of course this doesn't come at the same price, see more in the best adresses pages.
The same, making a kiwi sorbet (the lid is off for the photo).
As you can see, it's quite expensive, but bearing in mind all the great ice-creams you can make with it, it's a good investment.
How to make ice-creams
- It's most important that your mixture is already very cold before going into the machine. So, when you've just finished preparing it, put it in a sealed bottle or jar in the fridge. Tip: you can also put it in the freezer for 30-40 minutes before putting it in the machine.
- For the ice-creams, you can prepare the mixture the day before, leave overnight in the fridge, and then put in the freezer for 30 minutes.
- Don't do this for sorbets because fruit purées lose their flavour, vitamins and colour quickly in the air. If possible, make the fruit purée in your blender at the last minute, then 30 minutes in the freezer, and finally into the machine. You can also add a pinch of vitamin C to prevent browning.
How to enjoy
- If you've done as indicated above, your ice-cream or sorbet should be ready in about 30 minutes, and smooth. As soon as it reaches the right texture, stop the machine and enjoy it! Your ice-cream will never be better than at this moment.
- If you are serving a frozen dessert to guests, calculate the time necessary so that your ice-cream is just ready at dessert time.
- If you want to make your ice-cream beforehand, put it in a sealed box in the freezer when done. Then transfer to the fridge 15 minutes before serving, to allow it to soften a little.
Better than an ice-cream maker
From all that has gone before, you should hold on to the idea that the more quickly ice-creams or sorbets are made, that is churned or set, the better they are. This is because during the churning small ice crystals form, which can give a rough texture to the ice-cream. So the quicker the process, the less time the crystals have to form, and the better the result.In that case, is it possible to make ice-cream even more quickly than with an ice-cream maker? Answer: yes, but it requires special techniques.
Liquid nitrogen
Liquid nitrogen is very strange stuff: it's a boiling liquid of gaseous nitrogen (the neutral gas that makes up 3/4 of our air) liquified and at -196°C.Clearly this is not something that can be handled like water, and certain strict rules must be observed (gloves and goggles as a minimum precaution), as touching the nitrogen or getting it on the skin can lead to serious burns.
I suggest you read the following on the subject: Liquid Nitrogen Safety (Oxford University). Warning: the author of this page can in no way be held responsible for problems or injuries resulting from the use of this substance.
It is not easy for private individuals to obtain, and you will need to find local suppliers via the yellow pages or search engines. I'll take this oportunity to thank a colleague in passing (who will recognise himself), without whom these experiments would not have been possible.
Once appropriate safety precautions are in place, let's see what use this can be for making ice-cream. Well, it's simply a matter of speed, ice-cream which freezes almost instantaneously. About an equal quantity of liquid nitrogen is poured into the mixture while beating energetically, which causes the ice-cream to freeze in a few seconds in spectacular billows of fog.
How is it done?
First prepare the mixture for your ice-cream or sorbet as usual; here it's vanilla ice-cream, then transfer it to a metal bowl.
Dry ice
Alternative and other strange product, dry ice is solid CO2 at -80°C, and can be used to make ice-cream again very quickly.The dry ice is in the form of large granules.
