Ice cream expansion ratio: definition, calculation and optimization
Is your ice cream lacking in flavor? Is it too light, too foamy, or too dense? The problem may stem from the expansion ratio.
This technical parameter is essential in ice cream making. It directly influences the texture, the taste quality, smarter investing and the profitability of your production.
What is the expansion ratio?
Le expansion ratio corresponds to the amount of air incorporated into the ice cream (or sorbet) during churning.
The more air an ice cream contains, the lighter and more voluminous it is. Conversely, ice cream with less aeration will be denser, richer in texture, and often more intense in flavor.
The goal is therefore not to incorporate the maximum amount of air, but to find the good overrun rate according to each recipe, each desired texture and each product positioning.
How do you calculate the expansion ratio?
The calculation is simple: we compare the weight of the same volume of mix before and after churning.
- Fill a container with the un-churned liquid mix, then weigh it: P1
- Churn the ice cream
- Fill the same container with the whipped ice cream, then weigh it: P2
Formula :
Swelling (%) = ((P1 − P2) / P2) × 100
Example: if a container filled with liquid mix weighs 1000 g and the same container filled with churned ice weighs 700 g, the overrun rate is 42%.
Why is knowing your expansion ratio economically important?
Overrun has a direct impact on the cost price. With the same quantity of mix, ice cream with a higher or lower overrun will not yield the same final sales volume.
For example:
- 1 liter of mix with 30% overrun yields approximately 1,3 liters of ice cream
- 1 liter of mix with 60% overrun yields approximately 1,6 liters of ice cream
Even with identical raw materials, the volume sold can therefore vary significantly. This is an important lever for improving profit margins on expensive perfumes.
Conversely, too little overrun results in denser ice cream, but increases the cost of ingredients per serving.
The impact of over-proofing on taste and texture
The overrun rate also plays a major role in the taste experience.
- A low overrun results in a dense, creamy texture and a more intense flavor.
- A high overrun results in a lighter texture, but can diminish the flavors.
Premium vanilla ice cream, lemon sorbet, Italian-style ice cream or tub ice cream will not necessarily have the same overrun objective.
Therefore, there is no single ideal rate. We must look for the good rise for each recipe.
How to optimize the expansion ratio?
1. Work on the balance of the recipe
The recipe is the first key factor. A poorly balanced mix will either not incorporate air properly or won't retain it correctly.
In particular, the following should be monitored:
- total dry matter
- the balance between sugars, fats and milk solids
- the choice of stabilizers and emulsifiers
2. Master the manufacturing process
The process strongly influences the stability of the bulking.
Proper maturation of the mix, an appropriate temperature and a homogeneous preparation allow you to obtain a more consistent ice cream.
Typically, a well-matured mix and working at around 4°C will promote better air incorporation.
3. Use a suitable machine
The machine plays a central role in the regularity of the overrun and the final quality of the ice cream.
A professional ice cream maker allows for finer control of texture, extraction temperature and production regularity, thanks in particular to its speed variator.
For certain needs, particularly in small-scale production or as a supplement to existing equipment, a professional ice cream maker can also be a relevant solution, provided that the recipe, process and production volume are adapted.
The mistake to avoid: trying to maximize the abundance
Good overrun is not necessarily high overrun.
Adding too much air can make ice cream look more profitable, but less flavorful. The taste is diluted, the texture becomes foamy, and the product image can suffer.
The right approach is to adapt the overrun rate to the type of ice cream, the recipe, the selling price, and the desired customer experience.
Conclusion
The expansion ratio is a key indicator for any ice professional.
It allows you to control both:
- texture quality
- the intensity of taste
- material yield
- production profitability
When properly mastered, it allows for the production of consistent, regular, profitable ice cream that is suitable for each recipe.
Need to optimize your recipes or machine settings?
At Hubert Cloix, we support ice cream professionals in choosing their equipment, laboratory testing and optimizing their production.
Do you want to improve the texture, yield or consistency of your ice cream?
Contact us to discuss your project.
