Anyone who has had any experience in the manufacture of ice cream or gelato knows that it is a lot more technical than you may at first realise. The importance of finding the right process, timings and ingredients for your recipes is key to the final stability, taste and texture of your frozen product. Many people spend time focusing on their ice cream/gelato ingredients but the process of manufacture is equally important. Prior to freezing there are two options for preparing the base mix of ice cream or gelato; the hot process and the cold process.
Firstly we will examine the hot process. The main difference between the two processes, from an equipment perspective, is that for the hot process you will need a pasteurising machine. So if you don’t have one of these and you are not intending to purchase one, or if you don’t have the facility to heat then cool in a pan, whilst constantly stirring and whisking, the decision is made for you - the cold process is your method.
So how does the hot process work?
The ice cream or gelato ingredients mixture is put into the pasteuriser. Take care to gradually add the stabiliser/emulsifier mix (which has already been combined with the sugar) to the warmed mixture, allowing complete dispersion of the liquid. There are some variations in the process, but generally we recommend heating with rigorous agitation to 85°C, then dropping the temperature rapidly to 5°C. Superior pasteurisers will then hold the mixture at fridge temperature with occasional stirring. A period of ageing is beneficial, typically 12 hours for a white base. Afterwards the liquid ingredients are put into a batch freezer where they are quickly frozen whilst being ‘churned’ to incorporate air in order to produce a smooth semi solid product, free from ice crystals. Some machines incorporate a pasteuriser and batch freezer ‘2 in 1’; they may require lower capital and take up less space. However, on the negative side there is no maturing of the mix and the preparation time for the base mix is significantly greater.
By putting your gelato/ice cream ingredients mixture through the hot process the bacterial count of the final product is reduced and the bacterial activity slowed down. This is particularly important if you are storing and/or distributing your product. The hot process also improves the quality of the base by thorough mixing of components; the molecules of water, protein, sugars, fats and other solids are reduced in size and attached to the water to produce a finer and creamier texture to your ice cream/gelato. This method also helps to fully activate the stabilisers, which in turn helps to create and maintain a gelato/ice cream with a good structure.
The cold process involves using sterile powders and liquid ice cream/gelato ingredients, which have already been pasteurised, so the mixture can be put into the batch freezer, immediately after the solids have been mixed and matured. Generally this process is used for making sorbets, as there are no dairy products involved; only water. However, there is a range of bases available from MEC3, which allows you to make milk based gelato without the use of a pasteuriser. Cold process bases can also be prepared using the hot process, so giving you the option of either method. It is also a popular method for those businesses with a limited space or for those who need to create their gelato at a faster rate. It should be noted that using the cold process means the mixture needs to rest for at least half an hour before use, additional time is an advantage, this enables the stabilisers to activate. For a milk/cream mix ageing should be done in a fridge.
Which Process is Best for You?
Obviously there is an element of personal preference of which process to use and some ice cream manufacturers still use traditional methods and recipes, which have been passed down through the generations. However the general conclusion about which process to use, is that a hot process gives a more refined ice cream/gelato with a finer texture and a superi
or quality, whilst a cold process works well for sorbets, or in situations where capital and space are at a premium. The cold process is a good back up if your pasteuriser is unavailable or out of action for some reason. If you are storing your frozen product for more than a few days or transporting it, most Environmental Health Officers (EHO) prefer to see the hot process in use, and when itcomes down to hygiene it is your local EHO that you need to impress.
As sole UK distributors for MEC3 flavours and ingredients, Antonelli supply a wide range of products to help balance and refine your ice cream and gelato recipes. See the ingredients section on our product pages for more details or to get advice on a particular recipe or process, speak to your Antonelli Sales Manager or contact us on 0843 515 1912 and ask for ‘Sales & Technical Services’.