Special Ingredients

Add the ingredient as components

Recall the principle of balancing from Chapter 5: gelato is designed in components, not ingredients. Nowhere does the principle work harder than on the special ingredients of flavor.

Chocolate carries in fat and sugar; nut paste, a great deal of fat; alcohol, a strong depression of the freezing point. Treat these as "flavoring" alone and add them, and the fat runs over, or the freezing point drops until nothing sets. The craft of the special ingredient is this: know what it brings in, and take that much out of the rest.

Chocolate and cacao

Chocolate is far from this fruit. Split the pod, and beans lie buried in white pulp — seeds not yet fermented, not yet roasted, neither bitter nor brown. The road from here to fat, sugar, and bitterness is what the formulation receives as "components brought in".

Chocolate (cioccolato) and cacao are taken apart into the fat — cocoa butter — and everything else, the cocoa solids. Count the cocoa butter as fat in the formulation, and reduce the milk fat by that much. The cocoa solids and the sugar are summed in their turn, as "other solids" and as "sugar". A flavoring, then — and at the same time a material that moves the main components of the formulation.

But this applies only to the use that dissolves the cacao into the mix. Cocoa powder or cocoa paste entering at the pasteurization step is counted as above.

Bar chocolate and coating chocolate, poured in at the end of mantecazione, are another story. The literature holds this use as the standard. The handling is the same as crushed almonds or hazelnuts — that is, it does not enter the count of the balance. The reason is plain: that fat and sugar take no part in the freezing. What enters after the mix has frozen touches neither the freezing point nor the unfrozen phase.

So decide first which use is in play. Reduce the milk fat for chocolate that goes in at the end, and the base thins by that much. The total fat balances on paper, and falls short in the mix.

Cacao is comparatively rich in starches and pectin, and these give the chocolate flavors their peculiar astringency — the slight tightening felt in the mouth. They drink water, so they reach the design of the water as well.

And one problem remains that matching the total fat does not settle. Chocolate gelato turns hard easily. The causes are mainly two: cocoa butter sets hard in the cold, and the fibers just seen. Here is the awkward part. Follow Fig. 10-1, reduce the milk fat, hold the total fat on target — and the hardness is not solved. Cocoa butter and milk fat are the same "fat" on the ledger, and behave differently at freezer temperatures — cocoa butter sets the harder. What is equal on the component sheet is not always equal in the mouth.

So the countermeasure is played on the sugar side, not the fat side. For the cacao gelato, the literature advises keeping the share of sugar always on the high side. If more sweetness is unwanted, choose sugars low in sweetening power — Chapter 2's "sweetness and hardness are designed separately" works here as it stands. One note on the material itself: alkalized "Dutch" cacao dissolves more readily, opens its aroma, deepens in color, and mellows in acidity and bitterness. The choice at the shelf already moves the result.

Nuts — roasting and fat

The nuts — hazelnut (nocciola), almond, and their kin — are the ingredient in which fat is the largest component. They are used as pastes, and unless this fat is counted into the formulation, the gelato comes out heavy with fat.

But "nuts = fat" drops two things.

One: the share of fat differs considerably by kind. Walnuts and hazelnuts run near six tenths — but pistachios and almonds stop at about half. "Mostly fat" is true only of the first two; in the latter two, half is something else.

Two: what that something else is. Nuts bring in sugar and protein. Sugar, about one tenth; protein, by kind, one to two tenths. Use pistachio paste at 10 percent of the formulation, and sugar above 1 percent and protein about 2 percent come in with it. The principle of this chapter was to think in components, not ingredients. If chocolate has its sugar summed, counting only the fat of a nut does not follow.

The flavor of a nut is decided by its roasting (tostatura). In gelato above all, the cold dulls flavor, so the roast is best taken somewhat stronger. The ideal is an even roast, graded by size, controlled in temperature and time. In practice that means the semi-finished pastes of the specialist makers. Milling to 15–20 µm is beyond the workshop.

A nut paste separates its oil as it stands. Before use, warm it gently over a water bath and knead it back to uniformity. Choose unsweetened pastes, and manage the sweetness separately, on the sugar side of the design.

Fruit — ripeness moves the components

Fresh fruit, on the formulation sheet, is water and sugar. As a very rough guide, the literature takes the residual solids of fruit as sugar: one tenth sugar, nine tenths water. But the value is truly rough — it moves with variety, ripeness, climate, and the soil the tree grew in. So design with fruit begins by measuring the actual sugar in Brix (Chapter 9).

Fruit divides in two by use. The pulp fruits (frutta polposa) are used flesh and all, skin and seeds removed; the juice fruits (frutta succosa) are pressed for juice alone. Surprisingly, the amount of water differs little between the two groups (banana is the exception). The pulp feels denser because of micellar matter and cellulose fibers. But their amount is very small, and what they give is closer to an appearance of substance. Do not mistake the pulp's "density" for a higher share of solids.

And fruits divide once more: those that ripen after picking, and those that do not — whether they carry post-harvest ripening. The pulp fruits — banana, pear, apple — are often picked half-ripe, and their ripening can be hurried or held. Warmth speeds it, cold slows it. The juice fruits, like the citrus, have no such power. Off the tree, ripening stops, and only decline follows. A lemon golden in the skin but harsh in its acid was picked before its time. Citrus must be bought ripe.

An unripe fruit is hard, sour, dry, and scentless. A ripe one is soft, sweet, juicy, and fragrant. Four changes make the difference: the pectin turns soluble, fructose is synthesized, water-holding compounds are cleaved, and the aromatic esters are synthesized.

"Ripening deepens the flavor" names two of the four. Sweetness and aroma are made together, inside the fruit. Fructose, as Chapter 2 showed, is high in sweetness and strong in freezing-point depression. So ripeness works on the formulation as well as on the flavor. The aromatic esters are released as the cells that held them give way.

The pectin can be followed one step further. In the unripe fruit it is insoluble protopectin, gluing cell to cell. As ripening advances, enzymes turn it into soluble pectinic acid. And this soluble form is pectin in the narrow sense — the acid-loving thickener of Chapter 4. Ripen past the peak, and it degrades further into pectic acid, insoluble again.

So ripeness has a peak. Too firm or overripe, and the pectin sits on the insoluble side. The most soluble pectin is held in between. If a sorbetto is to lean part of its structure on the fruit's own pectin, that one point is the target.

What to look for comes down, in the end, to two things. Does this fruit ripen after picking, or not? And where on the peak does it stand now? Add that the discard — skin and stone, the yield — differs widely by item, and works on the cost side (Chapter 15). The handling of acid belongs to Chapter 9.

Alcohol — a little, and last

Alcohol is the hardest ingredient to handle. As Chapter 2 showed, ethanol's molecular weight of 46 gives it PAC 743 — more than seven times the anti-freezing power of sucrose. That value is per gram of pure alcohol, and the alcohol of an actual liqueur or wine is only a fraction of the bottle. It is still too strong. And beyond the freezing point, alcohol destabilizes the proteins, and hinders the hydration of the stabilizers and the work of the emulsifiers. The machinery that supports the structure of gelato — it interferes with all of it.

Sweet wines and aromatic liqueurs are used all the same, less for their own sake than to round the taste and lift a particular aroma. Volatile as they are, a very small amount gives depth. If used, hold to the rule:

There is a reason ② is one pair. Cut the sugar, and the freezing point comes back — but that answers nothing about the hindered hydration of the stabilizers. Of the three interferences named above, the sugar cut settles only one: the freezing point. The other two — destabilized proteins, disabled stabilizers and emulsifiers — need another hand. So the stabilizers are raised. Do one half only, and the numbers close while the texture breaks.

④ is care of the same kind. A mix carrying alcohol is weak in structure, so the time until it is frozen through must be kept short.

Like the acidifiers (Chapter 9), alcohol is an ingredient added last. Keep the mix stable to the end, and finish with the spoonful — this order is the common manner of the late-added ingredients.

Egg — components and obligations

Adding egg yolk (tuorlo) to a crema formulation is a classic of gelato. Yet when the yolk is spoken of, the word that comes out is usually one — "richness". By the principle of this chapter, that is an ingredient not yet taken apart into components. What the yolk brings is fat, solids led by protein, and water.

Broken into components, what to subtract is decided. The yolk's fat, though it comes from no cow, is fat on the formulation sheet. Add it to the fat, and reduce the cream by that much. Note that while the total fat holds, the milk-fat content itself falls. Near the borders of the legal categories, this touches the classification of Chapter 14. The protein is not from milk, so it is counted under other solids, not MSNF. And the yolk is no dry powder: the water it carries — about half of it — is counted as water. Here the formula of Chapter 5 comes into play. The yolk pushes up fat and other solids both, and the formula lowers the MSNF ceiling twice over. To add yolk is to narrow the room for milk solids.

The replacement does not stop at components. The yolk brings an emulsifier along with its fat — the lecithin of Chapter 4. So the added emulsifier is counted after subtracting what the yolk already covers. The yolk itself, in excess, turns against you: Chapter 13 lists "too much yolk" among the causes of the spongy defect. The literature bundles the egg's functions into two: destabilizing the fat, and binding water. The former is the partial coalescence of Chapter 4 itself. The latter runs by a road of its own, apart from sugar and from stabilizers. A heated egg keeps hold of about 74 percent of the water it carried. And much of that bound water does not freeze at 0 °C. The water that freezes only lower down increases. Where sugar lowers the freezing point by the count of its molecules, the yolk removes freezable water itself. To give the yolk a PAC factor is, for that reason, to mistake the mechanism. Think of it as thickening the unfrozen phase of Chapter 1 — through a different door than the sugars.

And the yolk's work cannot be taken piecemeal. Emulsifying, foaming, binding, color, aroma — they come as a bundle. That is why taking or leaving the yolk is a judgment of taste, even more than of technique.

On the hygiene side, the choice is between breaking shell eggs and using pasteurized liquid egg. Contamination comes from the outside of the shell — and from inside the egg. Choose the shell, and the breaking itself becomes a step of the process. The general rule of hygiene applies to the eggshell as written: wash and disinfect the hands after handling raw materials bound for heating (Chapter 17). The literature is more concrete still. Break the eggs in a dedicated place, away from other work. Where no dedicated place can be had, use a shared place only in hours when no other work is done at all. Do not break the egg on the rim of the receiving vessel. Clear the shells away as they empty. Receive the yolks five or six at a time in a small vessel; check them; then pass them on to the large one. One bad egg must not spoil the whole. The zoning and the hand discipline of Chapter 12 come from this side, the shell's. The inside is the business of the heat.

That heating has a floor in law. In Japan, food made, processed, or cooked with hens' eggs must be heated, somewhere in the process, to 70 °C for one minute or more. A method of equal or greater killing effect also serves. The exemptions are two. One: pasteurized liquid egg. Two: fresh eggs fit for eating raw, within date, broken and cooked without delay, the food then eaten without delay. Gelato does not meet the second. It is frozen, hardened, and spends days in the display case. So the workshop has two roads and no third: pasteurized liquid egg, or a mix that carries its egg through the heat.

Nor is "liquid egg" one thing. The standards separate pasteurized from unpasteurized liquid egg, and the negative test for Salmonella is required only of the former.

Ice cream products, meanwhile, already carry a heating standard on their raw materials (Chapter 6). Think of the egg's requirement as one more layer on top of it.

Heat has more than hygiene behind it. The literature gives three reasons. The egg is the most dangerous carrier of pathogens among the raw materials. Its binding develops only through heat. And heating drives off the egg smell. Hygiene, structure, and flavor ride on the same step.

There is an upper bound as well. Where the yolk is reduced and the water is high, overheating past 83–85 °C makes the proteins release their water, cluster, and harden. The high pasteurization of Chapter 6, at 85 °C, sits against that line. Do not read only the floor and conclude that hotter is safer.

Unlike alcohol and the acidifiers, the egg is not an ingredient added last. The reverse — it enters first of all.

The rules described in this section are Japanese law. Your country or region has its own rules, and they change. Always confirm the current requirements with your local food authority.

Records carry the reproduction

With ready-made materials — frozen fruit, semi-finished pastes — record the date, the amount, the sugar level, and the kind. A new lot brings new components. Traceability serves hygiene (Chapter 12), and it serves the reproduction of taste no less.