How Is Gelato Made?
An overview of the materials and steps involved in creating the dessert of the Gods.
Introduction
As we saw earlier, Gelato is an incredibly complex product, composed of a variety of substances in different states interacting with each other. To complicate matters further, it is served at a temperature outside the range found on most places on earth.
If that was not enough, the above must happen within the requirements of the four cardinal virtues of Consistency, Mouthfeel, Flavour and Visuals. This may give an idea of how making this happen consistently and dependably involves a complex production chain and strict processes.
In this article we will dissect this production chain to have an overview of all that goes on when we are actually making Gelato.
Read on!
In Gradibus Exitum
They say the one thousand mile journey is taken step by step. It is the same with Gelato making — in order to come up with the dessert of the Gods, a number of steps are followed, in which different Materials are used, which must be put together and changed through certain Processes, according to specific Workflows.
It may sound complicated but is nothing to be scared about. In the following sections we will break each category down and in a snap you will understand how they get together.
Let's start with …
1. Materials
These are the physical stuff that either gets into or comes out of our Gelato-making process and can be broadly divided into Input and Output products.
Input products are those that make up the recipe and are mixed together. They can be divided into two groups:
Base Ingredients
The basic substances that provide the foundation on which we will incorporate the flavouring. These will vary according to the type of Gelato and in broad lines usually are:
- Gelato: milk, cream, sugars (sucrose, dextrose, glucose syrup, invert sugar), skimmed milk powder (SMP), stabilisers;
- Crema: same as gelato plus egg yolks;
- Sorbetto: water, sugars, fibre, stabilisers;
- Vegan Gelato: water, sugars, fibre, plant protein and fat, stabilisers.
Flavourings
The ingredients that provide the actual flavour of the Gelato. They come in all shapes and forms, some being more common and others more niche. Flavourings don't necessarily need to be sweet or dessert-related — the chef’s imagination is the limit.
- Nut pastes: Pistachio, hazelnuts, almonds, pine nuts, etc.; ground to a paste form;
- Chocolate: Chocolate (in pieces or callets), cocoa powder and/or cocoa mass (sometimes called liquor);
- Fruits: Fresh fruit pieces, pulp or juice;
- Infusions: Coffee grain, tea leaves, vanilla beans, herbs and spices, are left in a liquid mixture in order to incorporate flavour. These can be infused hot (strictly speaking infusion) or cold (usually called macerated);
- Alcoholic: Beer, wine, prosecco, whisky, Aperol.
- Others: Caramel, breads, cakes, biscuits, etc.
Worthy of mention are flavouring finishes. They are slightly different from the flavouring itself in the sense that they are not part of the mixture but are instead added to the frozen cream. They usually come in two varieties:
- Liquid: these are thick sauces or syrups that can be folded in the cream, added as a topping, or as a covering layer. Usually called variegato in Italian, with several names in English (i.e. ripple, sauce, syrup);
- Solid: these are pieces added to the cream, either on top or folded within. They can be whole or crushed nuts, fruit pieces, diced herbs, crumbled or pieced cookies, etc., and are called inclusions.
Output products on the other hand are what comes out of mixing Input Products together, and can be split into three distinct groups:
Base
Depending on the production method used, the first output product created will be the Base. It is essentially a mixture containing all the base ingredients, in a dosage that will yield the desired consistency and mouthfeel; (see Workflows below)
There will normally be a base for each type of Gelato that will be produced. These are usually called: White or Milk Base for classic Gelato; Egg Base for Crema; Vegan Base for Vegan Gelato. Few Gelatiere have a base for Sorbetto, as it is more common to use a Syrup instead.
Some Gelatiere however have specific bases for different types of flavourings (i.e. Chocolate, Nuts, Fruits). The reasoning behind is that different flavourings have different functional characteristics (i.e. Chocolate and Nuts have a lot of fat and solids, while Fruits have little) and by tuning each base to these we achieve more consistency across flavours.
Mix
This is the liquid mixture that contains the flavourings and base ingredients blended together. It contains the taste and smell of the finished product and is fine tuned to yield the desired consistency, flavour and mouthfeel.
Cream
The final product coming out of the freezing process, although not necessarily ready for serving (see Hardening below). Provided the previous steps were followed correctly, it contains all characteristics of consistency, mouthfeel, flavour and visuals.
2. Processes
These are the series of actions taken in order to transform input materials into output ones.
Recipe Development
The cornerstone to achieve the four cardinal virtues of consistency, mouthfeel, visuals and flavour is the recipe. The careful dosage of ingredients is the foundation which will allow us to achieve the results we want. For that reason, most creative Gelatiere spend a considerable amount of time developing recipes for new and classic flavours, to make sure that they are putting out the best results possible.
Achieving this right dosage between ingredients is called balancing (bilanciamento in Italian). The goal is to adjust the amount of each ingredient in the recipe according to their functionality, the ultimate goal being certain parameters acknowledged as most favourable to achieve the four cardinal virtues. Balancing is so fundamental in Gelato making that we will dedicate a whole article to balancing in a future article, so watch this space.
Balancing can be done in several ways:
- Manually: Pen and paper and a little bit of maths are all you need to balance any recipe once you know how it works. That is actually how people did it not long ago, so that is still an option today;
- Spreadsheet: All that there is to balancing are a few calculations, so any spreadsheet application such as MS Excel, Google Sheets or Apple's Numbers can be used to create a versatile balancing tool;
- Dedicated Software: This is the pinnacle of convenience, where all calculations and a considerable database of ingredient parameters are provided as a standard. There are numerous apps available on the market at the moment. I will write a full article dedicated to them, but if you are curious in the meanwhile, just google 'gelato balancing app' and having browsing through the endless options you will find.
Pasteurisation
Dairy and eggs are considered high risk foods (both being an excellent media for microbe growth) so any food containing them will be required to go through a heat process to reduce the risk of food poisoning when sold to the public.
This process is called pasteurisation and is the first process of actual production, and an integral part of any commercial Gelato production workflow.
Parameters vary from country to country depending on food safety regulations, but the most common standards are:
- Low Pasteurisation: Heat to 65° for 30 minutes;
- Mid Pasteurisation: Heat to 72º for 5 minutes;
- High Pasteurisation: Heat to 85° for 5 seconds.
An added benefit of pasteurising our bases is that they are required to activate certain stabilisers, something we will discuss later.
Pasteurisation can be done manually using a stove and a pot, but this is not very practical and dedicated equipment called pasteurisers are used in commercial production.
Lastly, if a flavour does not contain dairy or eggs (i.e. Sorbetto or Vegan) and the stabiliser used doesn’t require heat for activation, pasteurisation is not required. This is called Cold Process, while pasteurising is called Hot Process.
Mixing
This is where the Base (or base ingredients) are combined with the flavourings to produce the Mix.
The usual approach in commercial production is to use a high speed immersion blender to achieve a homogeneous and consistent mixture — the higher the blending speed, the smaller and finer the ingredients are broken up, resulting in improved texture and flavour perception.
Alternative methods include manual whisking, which produces the least optimal results, with higher risk of lumps or grainy pieces); and using cup blenders, which can achieve even higher speeds than immersion blenders but usually have a limited capacity (up to a couple of litres).
At home, either a consumer stick blender or a properly sized cup blender do the job pretty well.
Ageing
As we mentioned in the previous article, a Gelato is a highly complex product in which several physical and chemical reactions occur. Allowing mixtures some time to rest before actually freezing them into a cream will give these reactions a chance to consolidate and yield better results.
Professional labs use dedicated machines that chill and slowly stir the base or mix for optimum ageing. At home, just leaving it in an airtight container already produces great results.
Times will vary from a minimum of 1 hour, a recommended 4 hours, and an ideal of 12 hours. In any case, never more than 72 hours, after which the mixture should be discarded.
Freezing
This is the moment when all the materials and effort put in so far actually turn into what we actually want to do: make Gelato. The process involves simultaneously freezing and agitating the mix to turn it into a semi-solid pasty state.
The agitation causes air to be incorporated (called Overrun). As discussed previously, this added air (in the form of tiny bubbles surrounded by fat and protein) is responsible for the soft and fluffy structure that our palates enjoy so much.
Freezing can be done in one of three ways:
- Manually: Placing the mix in the freezer and agitating it manually at regular intervals. This is the method used by some home enthusiasts.
- In a batch freezer: This is a machine that contains a barrel and a rotating paddle. The mix is placed in the barrel which is cooled by a compressor, gradually lowering its temperature to subzero values, while the paddle agitates it continuously to incorporate air. This is the method used by all artisan Gelaterie. The process of taking the gelato out of the batch freezer is called ‘extraction’ or ‘drawing’.
The name batch freezer comes from the fact that only a certain amount (determined by the barrel’s capacity) can be produced at once — a batch. Batch freezers come in all shapes and sizes, from small portable machines for home use to humongous metal beasts for large artisan operations. - In a continuous freezer: Different to its batch cousin, a continuous freezer is able to relentlessly spew out cream as long as it is switched on and fed with mix. This is used for industrial production only, therefore is beyond the scope of our publication and, strictly speaking, no authentic Gelato (with a capital G) can be produced this way.
Hardening
Save rare exceptions, the cream coming out of a batch freezer will not be at serving consistency. To do so would require extreme freezers (to cool the mix down to very low temperatures) and would make the extraction process much more difficult, as the cream would come out considerably harder through the extraction port.
So Gelato is usually extracted between -6° and -9°C, when the structure is stable (i.e. all air has been incorporated) and it is still soft enough to be extracted and moulded in appealing shapes with ease.
To reach the serving temperature, the recently extracted cream will be placed in a blast freezer — which will cool it down to the serving temperature within 10–15 minutes (the quicker the better for quality reasons, as we will see in a future article about ice crystals).
At home however, the cream will be placed in the freezer (which is usually able to cool down 1kg of gelato at a rate of 1° every two hours). Some enthusiasts place a USB powered fan in the freezer to increase cooling speed. Although this may sound a bit over the top, it works quite well.
Serving
Finally the moment to actually enjoy the outcome of all the work we have put in so far has come. Hooray!!
And here too, in order to yield a Gelato with capital G some strict and specifc requirements are enforced. For starters, the recommended serving temperature will range between -10º and -14°C.
Which temperature to choose depends on a number of factors, ranging from recipe formulation to intended method of sale. For practical purposes we will consider a serving temperature of 12°C across our articles, unless otherwise stated.
The relatively high serving temperature (remember that the temperature in a domestic freezer usually ranges between -18° and -24°C) has two main implications. On the one hand, it results in a less cold cream, which keeps not only your sensitive teeth happy but above all your tastebuds: not being frozen to numbness, they can enjoy the flavour much more intensely! On the other, because the cream is not so hard frozen, it is possible to use a spade to serve it, allowing for shaping the scoop in eye catching creative forms.
And there you go, you have learned a way to spot authentic Gelato from copycats: if they are served with scoopers, raise your eyebrows!
3. Workflows
Finally, it is time to talk about workflows. These relate to how processes are grouped and/or linked together depending on the circumstances of the production lab and/or point of sale.
Although individual steps may vary slightly from one producer to another, workflows can be divided into two broad methods of working:
Classic Method
It consists of pasteurising large batches of Bases at once, which are then left to age. Once sufficiently aged, the Base will be blended on demand with flavourings to create Mixes.
Because the flavourings will have their own functional characteristics, the Mix will usually require some form of re-balancing (ribilanciamento in Italian).
The Mix is then batched, hardened and served/stored.
The main advantage of the classic method is workflow optimisation — a lot of time is gained by producing large quantities of Base at once — and its main disadvantage is that it is difficult to fine tune the recipe of each flavour.
It is the method used by virtually all gelaterie with a high volume of production.
Direct Method
In this method no Base is produced in advance and all ingredients (basic and flavourings) are mixed within the same process. Different ingredients may be added at different stages of the pasteurisation process (some of them benefit from higher temperatures, while others can be damaged by it), but the Mix is finished at the end of it, and only ageing is required before batch freezing.
It is a more laborious method because it requires to go through all steps (i.e. weighing, mixing, etc.) for each flavour, but it allows a highly accurate balancing. For this reason it is more commonly used in highly artisan gelaterie with a small production volume, and at home.
Implications of Workflow
Depending on the workflow/method used, the recipe will be formulated differently. A Pistachio recipe, for example, would look like this in a Classic Method environment:
Which would require a separate White Base recipe which might look something like this:
In a Direct Method environment however it would look like this:
The recipes at the top and bottom would yield a very similar Gelato. If you have an experienced eye you may have spotted a detail that might make the bottom one slightly better. And you don't need to be an expert to realise just by looking at the recipes that it is a lot quicker to prepare the one at the top — which is why the Direct Method is preferred by most high volume labs.
So far so good!
Before We Go
I know we have covered a lot of ground in this article and it might have been a lot of information to take in. To make it easier to have a complete overview of everything involved, I created the flow diagram below.
I hope it will help you get the full picture and that it will stay with you.
And this closes this article — you should now have a complete overview of all the materials, steps and machinery used in Gelato making.
Tap on the back!!
Wrapping Up
Making Gelato is a fun activity but involves a myriad of materials and processes which, depending on how they are organised, lead to certain workflows. These are:
Input Products
1. Base Ingredients: Those materials that, when mixed together, provide the foundation upon which flavourings will be added. Normally they will be neutral in flavour. Common examples are milk, cream, sugars, fibres and stabilisers;
2. Flavourings: Those which provide the flavour or flavours of the final product. Examples are fruits, chocolate, nuts (usually in paste form), etc., but include a broad variety;
3. Sauces and Inclusions: Liquid or solid ingredients which are added to the finished product to give it extra flavour or an enhanced texture. Examples are variegati di frutta; ripples, crunched nuts, chocolate pieces, etc.
Output Products
4. Base: This is the first Output Product in the Classic Method (see below) and consists of a mixture containing only Base Ingredients, carefully balanced to yield the desired consistency and mouthfeel;
5. Mix: This is the final flavoured liquid mixture, obtained by combining either a Base or a number of base ingredients with flavourings.
6. Cream: This is the output of the freezing process, in a semi-solid state, and containing all target characteristics of consistency, mouthfeel, visuals and flavour.
Processes
7. Recipe Development: The careful dosage of the ingredients according to their functional and organoleptic characteristics. The act of calculating the dosages to achieve the desired outcome is called balancing (bilanciamento in Italian) and can be done manually, using a spreadsheet, or via dedicated software;
8. Pasteurisation: The process of heating foods to a certain temperature for a certain amount of time. This is normally a requirement when handling high risk foods (i.e. dairy and eggs) to kill microbes, and is necessary to activate certain stabilisers. Parameters are usually: 65ºC for 30' (low pasteurisation); 72ºC for 5' (mid pasteurisation); 85ºC for 5" (high pasteurisation). Called Hot Process, as opposed to Cold Process when it is not required (i.e. Sorbetto or Vegan).
9. Mixing: The process of combining the Base (or base ingredients) with the flavourings to produce the Mix, using an immersion blender, cup blender, or manual whisk.
10. Ageing: Allowing the Base or Mix to rest for a few hours in order for chemical processes to consolidate. Minimum recommended ageing time is 4h, ideally 12h, but never more than 72h. It can be done in the pasteuriser tank, using dedicated ageing vats, or in a fridge in sealed containers.
11. Freezing: The aged mix is finally frozen while being agitated to incorporate air (called Overrun). The process can be done manually, using a Batch Freezer (an artisanal machine) or a Continuous Freezer (an industrial machine).
12. Hardening: The Gelato coming out of a Batch Freezer is not at serving temperature yet so needs to be further cooled before serving. Ideally this will be done using a Blast Freezer to avoid the loss of quality caused by slow changes in temperature.
13. Serving: Gelato is served at the relatively high temperature range of -10º to -14ºC. This is different from the temperature range of domestic and industrial freezers (-18º to -24ºC). The main benefits of the higher temperature is that tastebuds can enjoy more flavour and the cream is softer, being easily served using a spade instead of a scooper.
Workflows
15. Classic Method: Large batches of Base are pasteurised and aged at once, with flavourings mixed on demand with minor rebalancing to produce Mixes for batch freezing. It is the fastest workflow, for scenarios of high volume output.
16. Direct Method: Each flavour is produced from scratch by mixing Base ingredients with Flavourings in carefully balanced dosages. It yields the most accurate balancing (and therefore theoretically better results) but is time consuming. Normally used in highly artisan, small production scenarios.
A presto!!
* Note: this story is part of a series of articles comprising an introduction to Gelato-making. You can access the full series here:
