Ice-cream is seldom far away from the dessert menu of any restaurant, and while it's possible to buy quality ice-cream from an artisan producer, it won't have the texture and individuality of flavours of ice-cream made by chefs in the kitchen. A menu that offers interesting ice-cream flavours will also have more sales appeal than the generic flavours a commercial ice-cream producer can offer.
Equipment manufacturers have long recognised the demand for low-volume but high-quality ice-cream makers and produce machines for small restaurants as well as busy ice-cream parlours. While there's a temptation to buy a domestic ice-cream machine rather than a commercial specification machine, the quality of ice-cream produced will be noticeably coarser.
The way an ice-cream maker works is very simple. The chef pours a chilled egg custard into the machine, which churns it slowly at freezing temperature until it forms the familiar smooth ice-cream. The churning process prevents large ice crystals which would form if the custard were just put into a freezer. Flavours can be adding during the making of the custard or at the point of pouring it into the machine, which is how most fruit ice-creams are made.
The best hard ice-cream is made using fresh eggs, fresh cream, sugar, fresh milk and a flavouring to make the hot custard. With so much fresh dairy produce being heated and then cooled, it's safe kitchen practice to use a pasteuriser for cooking and cooling the custard. The machine works by mixing the custard, taking it up to 85°C for pasteurisation, then rapidly chilling it down to a safe 4°C.
For restaurants with limited equipment budgets, it's possible to avoid buying a pasteurisation unit by using a blast chiller to safely pull down the temperature of the custard.
The lasting quality of ice-cream improves if the chilled custard mix is matured for between eight and 72 hours. This allows any added emulsifiers and stabilisers to work on the mixture in addition to the natural stabilising effect of fresh eggs. Any form of stabiliser prevents the ice-cream from crumbling, which could happen if batches are to be held for more than 24 hours.
A smooth, rich product needs exact recipes. A common mistake is to think that adding lots of pulped fruit will give a better product, but too much fruit will upset the sugar balance and inhibit smooth freezing of the ice crystals. Equally, introducing too much fat in the form of eggs or cream will also cause the ice-cream to misform.
After the maturing time, the custard can be poured into the ice-cream maker for churning. Most machines have a signal system that indicates when the ice-cream is ready for decanting into storage tubs for hold and freeze.
An ice-cream maker can also be used for iced fruit desserts such as granitas and sorbets.