What is ice cream,
really?
Ice cream is not just “frozen cream”. It is one of the most physically complex foods there is: ice, air, fat, sugars and water living together in balance. Understanding that balance is what separates a creamy ice cream from a sweet block of ice.
Ice cream is a partially frozen foam: tiny ice crystals and air bubbles caught in a creamy syrup of fat, sugars and milk solids that never freezes solid.
The players
in the mix
Change the proportions and the ice cream changes. Open each element to see what it contributes and what happens when you overdo it or fall short.
The ingredient you do not pay for
Air is one more constituent of ice cream, and one of those that most govern how light or firm it feels when served. It is worked in during churning, taken from the air of the workshop itself.
Fat: body and richness
It comes from cream, milk or vegetable fats. It coats the air bubbles and lubricates the palate: it is the main reason for that unctuous feel, for body in the mouth and for the ice cream melting slowly and roundly. The sweet spot is at 8 %: it is the figure master ice cream makers recommend. Below it, richness is lost; above 12 %, it coats and dulls the flavour.
A rich mouthfeel, a round body and good resistance to melting.
Too little: less richness and it melts sooner. Too much: it coats and dulls the aromas.
Sugars: sweetness and antifreeze
They do two jobs at once: they bring sweetness (POD) and lower the freezing point (PAC). Each sugar — sucrose, dextrose, fructose, invert, honey, glucose… — pulls in a different direction, which is why one is almost never used on its own. Sucrose is the reference, with POD 1; dextrose sweetens less but freezes almost twice as much, and that is the trick that lets the scoop come out without a fight.
Balanced sweetness and an ice cream that is creamy and scoopable at serving temperature.
Too few: hard as a rock and dull. Too many: cloying and it never sets properly.
Milk solids: structure
These are the milk proteins and lactose, brought in above all by skimmed milk powder. They hold water, give body and help keep the ice crystals small: that is what you perceive as a fine texture. But that milk powder carries a 52 % lactose, and past 6 % of the total it crystallises and leaves an unmistakable sandiness. That is its ceiling, and it is best not to go near it if the ice cream will spend days in the freezer.
A firm body, a fine texture and good water retention, with fewer ice crystals.
Too few: weak, icy ice cream. Too many: sandy texture from too much lactose.
Stabilisers: controlling the water
In tiny doses — tenths of a percent — they bind the free water and stabilise the fat emulsion. They slow ice-crystal growth during storage, which is when ice cream really tends to go bad. They range between 0.3 and 0.6 %, and they have to be stirred dry with some of the sugar: tipped straight onto the liquid they clump and nothing will break them up.
A texture that holds over time and less crystallisation after days in the freezer.
Without them: it melts fast and crystallises early. In excess: gummy and heavy.
Water: the raw material of ice
It is the biggest component and the one that freezes. The whole job is governing how it does it: below about 40 microns the mouth reads it as cream; from about 50 it starts to notice them, and past 100 the ice cream reads as clearly coarse, icy. Coming out of the machine only half the water: the freezer handles the rest, and that is what makes it keep.
Frozen into microcrystals, it gives that creamy feel with no lumps of ice in the mouth.
Too much free water, or water poorly handled: big crystals, coarse texture and hard ice cream.
Air: the invisible player
It does not show on the scale, but without it there is no ice cream: it is worked in while churning (the overrun) and it aerates the mix. A home machine puts in between 20 and 40 % of the volume — which is why a litre of ice cream weighs far less than a litre of mix. Those bubbles measure between 50 and 80 microns, almost the same as the ice crystals around them: that is why, when the crystals grow, they burst their walls and the ice cream loses air.
Light and creamy: the scoop comes out easily and the cold does not numb the flavour.
Too little: dense, hard and very cold. Too much: foamy, with no body and little flavour.
Why good ice cream
never freezes solid
At serving temperature, between −12 and −10 °C, only part of the water is ice. The rest stays as unfrozen syrup: that is why you can scoop it.
Below that, more water freezes, the crystals grow and the ice cream turns hard as a rock.
Measures how much the recipe sweetens compared with ordinary sugar, which is the reference: sucrose = 1.
Measures how far it lowers the freezing point. The higher the PAC, the softer the ice cream stays at the same temperature.
Types of ice cream
by composition
In the UK the names come from the Food Labelling Regulations: what separates one from another is not the flavour, it is the fat and the milk protein.
Read the label, not the photo
«Dairy ice cream» needs at least 5 % fat and 2.5 % milk protein; plain «ice cream» allows vegetable fat. The legal name tells you more than the picture on the tub.
Dairy ice cream
In the UK, dairy ice cream needs at least 5 % fat and 2.5 % milk protein.
Ice cream
Plain «ice cream» needs at least 5 % fat, but that fat does not have to be dairy fat.
Reduced-fat ice cream
No separate legal name: what counts is whether it is dairy ice cream or plain ice cream.
Ice cream
At least 5 % fat, dairy or vegetable, and milk protein for dairy ice cream.
Water ice
A water-based frozen product; it cannot be called ice cream.
Sorbet
Sorbet is not a legal name in the UK: it is used by custom, for water-based fruit products.
Careful with «sherbet» in English
In the United States it is a legal name and asks for 2 to 5 % milk solids. In the UK a sherbet is a fizzy sweet, not a frozen dessert.. That is why one tub can carry two mentions at once: they are two labels that add up, not two different types.
«With strawberry» and «strawberry flavour» are not the same
In the UK there is no legal threshold for naming the fruit 15 % —a 10 % for citrus and exotic fruit, and a 7 % for nuts—. Where the law does not reach, read the ingredient list. «flavour».
In the UK there is no minimum weight per litre
Spanish law does set one: if so much air goes in that the litre drops below 430 g, it can no longer be called ice cream. That limit does not exist here. foam, mousse o whipped.
Artisan and
industrial ice cream
The law does not distinguish between artisan and industrial: the seven names above apply to both. What really separates them is not in the name, it shows on the tub and it shows on the spoon — and almost all of it comes down to a single figure: how much air it holds.
Check it yourself at the supermarket
The pack shows the volume in millilitres and the net weight in grams, though never together. Divide the weight by the volume and you will know what a litre of that tub weighs. It is the only way to see how much air you are paying for.
Air is what separates them most
Industrial ice cream can reach 100 % air: half the tub is whipped air. Artisan stays well below that. So, for the same volume, the artisan one weighs a good deal more than the industrial one.
They are made in different ways
Artisan ice cream is churned in the workshop in small batches and is sold within days. The industrial one is produced continuously and is designed to survive transport, the warehouse and weeks in the supermarket freezer.
Milk fat or vegetable fat
The artisan works with milk, cream and fruit, which is what gives flavour and body. Industrial production often turns to vegetable fats and flavourings: they cost less and give the same result in every batch of the year.
Why your
homemade ice cream goes wrong
Almost every problem at home comes down to one of these five. The good news: they all have a technical fix.
It tastes and crunches of ice
Big crystals from too few solids, too much free water or slow churning. Raise the dry extract and chill the mix well before churning.
Comes out hard as a rock
Not enough antifreeze (PAC). Swap some of the sucrose for dextrose or invert sugar: they lower the freezing point more and it stays scoopable.
It cloys or tastes of nothing
POD out of balance. Too much sugar covers the flavour and softens too much; too little leaves it bland and hard. Measure the sweetening power before correcting the formula.
Melts into a puddle
No stabiliser or no ageing. Hydrate the mix cold for a few hours before churning: it holds the water and stands up better on the plate.
Crystallises after two days
Temperature swings in the freezer. Cover it in contact, keep it at a steady −18 °C and avoid opening and closing: the swing recrystallises the water in the ice cream.
The root of nearly everything
Formulating without measuring. Start from a balanced recipe and understand what each number does. And if yours already came out odd, diagnose your ice cream.
Four words
you will always hear
Master them and you will understand almost any ice cream recipe or formula.
You will see them in all our recipes and in the calculator: they are the language of formulas.
The increase in volume from the air taken in while churning. Too little = dense and heavy; too much = foamy and bland.
Everything that is not water: fat, sugars and solids. The more total solids, the less free water and the more creaminess.
Freezing while beating at the same time. That beating breaks the ice crystals and takes in air: it is the step that gives the texture.
The cold resting of the mix before churning. It hydrates proteins and stabiliser and improves body and texture.
Now you know what it is.
Now, what it is made of
You now know what goes on inside: fat, sugars, air and cold working together. The next step is bringing it into your kitchen — the equipment you need, the ingredients you will buy and the whole process, step by step.
Frequently asked questions
What is the difference between artisan and industrial ice cream?
On how much air they carry, in the kind of fat they use and in the pace at which they are made. The law, on the other hand, does not tell them apart: the legal names apply to both. You have it set out above, in the artisan and industrial block.
What is overrun, the air in ice cream?
The air taken into the mix while churning, measured as a percentage of the starting volume. It is not a trick to sell less product: without air, ice cream cannot be eaten, it would be a compact block. What changes between a good one and a bad one is how much goes in.
Why does ice cream never freeze solid?
Because the dissolved sugars lower the freezing point of water. At tub temperature there is always part of the water left unfrozen, and it is exactly that part that lets you get the spoon in. In each of our reviews we tell you what percentage freezes at each temperature.
Is mantecado a flavour or a technique?
Both, and hence the confusion. To churn is the technique of freezing while churning. Churning, by contrast, is a legal designation with a specific egg yolk requirement, not a flavour: you have it above, with the figure. That people ask for «a mantecado» meaning the classic flavour is another story.
Are ice cream, gelato and sorbet the same thing?
No. The gelato is Italian-style ice cream: less air and less fat than the American kind, and served a little less cold. A sorbet has no dairy, it is a base of water and fruit. And «ice cream» covers everything, which is part of the confusion.
How many families of ice cream are there?
Careful, these are two different lists. The legal designations are the ones you see above and they rule the label. Separately there are the formulation families that we work with: the calculations change, not the legal name. And the rest — vegan, lactose-free, sugar-free — are variants of one base, not families of their own.
The theory,
told to suit you
We send you the technical guides and the new recipes as soon as we publish them. No spam, just ice cream done properly.