PAC
The notion of Potere Anti Congelante is also from Italian origin. It is not really documented in french gastronomic literature. We must therefore refer to italian or american publications for more information.
American ice-cream makers will use the notion of AFP (Anti Freezing Point) or FPDF (Freezing Point Depression Factor) with a small difference nevertheless. In their AFP/FPDF calculation, they will not take into account the effect of lactose from dairy products. In PAC calculation, all the ingredients are taken into account.
For ease of reading, only the term PAC will be used on Ice Ice Daddy .com and calculations will be made with the european method ie with all the ingredients.
How can it be useful for ice cream ?
If you have ever made homemade ice cream, you must have made ice cream as hard as a brick right out of the freezer. And no other choice than waiting a certain time before hoping to be able to scoop.
Imagine this situation in your favorite ice-cream shop with its dozens of ice-cream bins. A method will have to be found so that the employee can serve your ice cream immediately when you arrive without having his wrists broken at the end of the day.
Profesionnals have therefore defined the concept of "scoopability". And it is precisely the PAC that will give an idea of the "scoopability" of the ice cream produced.
An example with a recipe of a strawberry sorbet read in a book written by a profesionnal ice-cream maker. PAC calculation for this recipe will give a low value which means that the ice cream will be extremly hard just out of the freezer so with a bad 'scoopability'. In the case of this recipe, no surprise because the author indicates that the sorbet must be removed from the freezer and placed in the refrigerator 20 minutes before serving.
Another example, on a well-known blog with a lot of ice-cream recipes. It is written that ice cream must be placed 40 minutes in the refrigerator or 20 minutes in the open air before serving it !
"Kids, do you want ice cream for dessert ? No problem, but you will have to wait 40 minutes ! " . Think also to the health risk of partially thawing / refreezing the product.
So if it is possible at home to avoid or reduce these waiting times before the service, let us do it.
PAC and serving temperature
The calculation of PAC value of the ice cream will not allow you to draw a direct conclusion. We must define a relationship with the serving temperature.
Homemade ice creams will be consumed when leaving the freezer ie at a temperature of - 18°C.
For ice-cream shops, things will be slightly different. Angelo CORVITTO explains that in an ice-cream cabinet, the lower part of the ice cream will be at -18°C while the upper part will be at -11°C. So, ice cream will be served at a temperature of -11°C.
In conclusion, at home, you must make an ice cream with a good "scoopability" at -18°C while an ice-cream seller needs an ice cream with a good "scoopability" at -11°C.
Do not worry, the online balancing tool will do all the calculations for you and will display the result.
PAC limitations
It is important to understand that PAC calculation of an ice cream is not an exact scientific calculation which will guarantee a result. The chemistry of the ice cream will result in your ice cream being perhaps a little harder or a little softer. Other parameters such as overrun will have impacts.
But not taking it into account at all is a guarantee to get a bad result.
Operating principles
On Ice Ice Daddy .com, the explanations will be simplified as much as possible. No complicated calculations, no mention of molar weight, curves ... If you want to go further, do not hesitate to consult some books and articles in the section References . The two points to remember are as follows.
First, to have a good "scoopability", an ice cream must contain when served 75% of frozen water. It is the 25% of unfrozen water that gives to the ice creams its softness.
If the ice cream is served at an upper temperature, there will be more unfrozen water so the ice cream will be softer.
If the ice cream is served at a lower temperature, there will be less unfrozen water so the ice cream will be harder.
The objective of PAC will therefore be to balance the recipe to reach this 75% of unfrozen water at the temperature where you will serve your ice cream.
Second, the PAC method is based on the following experience. Water freezes at 0°C. If you add some sugar in the water, the mix will freeze at a temperature lower than 0°C.
For example, a mix with approximatively 18% of standard sugar (sucrose) will freeze at -1°C. And a mix with approximatively 18% of fructose will freeze at -2°C.
Here the goal of PAC method : controlling thanks to sugars combination the rate of unfrozen water and so the hardness/softness of the ice cream.
As seen with POD, sucrose will be again considered as a reference and will have a PAC value of 100. All other sugars will have their own PAC value with for example a PAC of 190 for fructose.
Is it difficult ?
No more thant it is for POD. You will use the same sugars but will make combinations depending their PAC value. And still no calculation ! The free online balancing tool of Ice Ice Daddy .com will do the work for you and will display the result.
Other ingredients with an effect on PAC
Salt and alcohol are well-known for their anti-freezing property. They will therefore be taken into account by the balancing tool to calculate the PAC value.
Chocolate is a special case. Chocolate ice cream will tend to be much harder. Beside the traditional PAC calculation method for chocolate, Angelo CORVITTO created a method with negative PAC. Ice Ice Daddy .com has compared these two methods.
With the standard method, the ice cream remains hard. The Angelo CORVITTO's method actually allows to have chocolate ice cream with a good "scoopability". But for that result, you have to increase a lot the PAC value and it will give an ice cream with a high sweet taste and a fast melting speed.
PAC calculation in the online balancing tool of Ice Ice Daddy .com will be done with the traditional method. If you wish to try the Angelo CORVITTO's method, make adjustments in the tool to adapt your mix to a lower serving temperature (-22 °C instead of -18 °C for example).