The Pac is the anti-freezing power that every sugar has. This is the value that delays the crystallization of the water in the gelato mixture.
This value determines the exposure temperature of the gelato and the softness.
The average Pac value for a kilo of gelato ranges from 290 to 320, while in fruit sorbets it ranges from 340 to 370.
If the gelato falls within these values, the gelato and sorbet can be kept at the same temperature in the display case between -13 and -15 ° C.
Within the gelato mixture they have two tasks:
There are two types of fats:
fats contained in the raw materials (we use them)
foreign fats, such as hydrogenated vegetable fats (we don’t use them!!!)
Why? Because a good gelato must melt immediately in the palate!
The fats we use have a melting point around 37 degrees Celsius, while the hydrogenated fats have a melting point of 42 degrees (also, they release greasiness on the palate and heaviness in the stomach and increase the bad cholesterol in the blood)!!
What does an excess of fat do in the mixture?
All fats tend to harden below 0 degrees. An excess of fats will make the ice cream harder and more compact (if not balanced well with sugars).
An excess of fat also hinders the incorporation of air into the gelato. So it doesn't produce a good overrun.
Without water and without sugar it is impossible to make gelato! This is the first fundamental rule for making ice cream.
The first characteristic of sugars is that of making the anti-freezing power (PAC) to the gelato mixture, which will serve to prevent part of the water from freezing and let it remain teasable at a shop window temperature from -12 to -14 ° C.
Anti-freezing power is the power that every sugar has to delay the crystallization of water, each sugar has its own value.
The different types of sugar are:
1. Saccharose (or white sugar)
1g of saccharose = 1PAC
Saccharose determines the sweetness of the recipe, and can be replaced in equal measure by brown sugar or cane sugar.
2. Dextrose (or glucose)
1g of dextrose = 1.85PAC
Dextrose is extracted from corn, grapes, dates and has an anti-freezing power that is almost double than the PAC of the saccharose and sweetens much less.
It is used in combination with saccharose to obtain a balanced sweetness in gelato. It also allows to obtain a long structure (thread) and does not recrystallize sucrose.
1g of fructose = 1.85 PAC
This sugar (that is naturally contained in fruit) has an anti-freezing power that is equal to dextrose but a higher sweetness.
1g of honey = 1.85PAC
Honey is a natural sugar which is composed of 40% glucose, 40% fructose and 20% water. It follows that the anti-freezing power is equal to fructose (and dextrose). Fructose with an intermediate sweetness, it is generally used to flavor recipes.
Called the invisible sugar because it is contained in milk and milk derivatives. To trace the correct amount of lactose we must read the food label under the heading "carbohydrates of which sugars".
Among the characteristics of lactose is that of absorbing a lot of water (about 10 times its own weight) and it has a sweetening power that is 9 times lower than normal sugar.
Lactose has a recommended dosage in recipes ranging from 40 to 60 g per kg of recipe, an excess of lactose makes the ice cream very spongy and floury.
There are two types of milk proteins:
casein whey protein (WPC)
In artisan gelato, whey proteins play a fundamental role. Whey proteins are directly involved in increasing the volume of homemade gelato inside the batch freezer (overrun). Casein, being much thicker and heavier, tends to thicken and create viscosity in the final blend.
However, proteins not only increase the volume of homemade gelato, but are also an important factor in giving creaminess to the gelato itself and enriching it with a milk taste. For a richer and creamier taste, it will be enough to add a little bit of casein to the mixture.
Whey proteins are identified by the acronym WPC (Whey Proteins Concentrate), an excellent indicator to ascertain the whey protein to be used in the preparation of homemade gelato. For example, for the preparation of a good homemade gelato those proteins that have a 80% WPC are perfect, while proteins with a 30% WPC are to be discarded, since the latter indicates a percentage of 30% of proteins and 55% of lactose.
A correct supply of protein in the gelato mixture ranges from 3- 4% on the total mixture.
One of the main characteristic of stabilizers is that of absorbing the water and making the homemade gelato more or less viscous.
The stabilizers with "hygroscopic" action are:
Locust bean gum (carob flour)
Guar seed flour
To these, in milk- based gelato, you have to add an emulsifier which has the function of binding water and fats to better characterize a gelato.
However, it is important to know that each stabilizer has its own characteristics, which make it interesting and peculiar, and through mixing it with another stabilizer the gelatiere is able to reach excellent results in the preparation of gelato.
For example, the carob flour has the ability to make homemade gelato more viscous, since it absorbs more water and creates a structure that slows the melting of the gelato itself. On the other hand, guar is a perfect stabilizer to absorb the air during gelato freezing. Moreover, by incorporating more air, thanks to the guar, and slowing down the dissolution by means of the carob, it can easily be understood that a right mix of stabilizers allows the preparation of the best gelato.