Learn the science behind:
How Eggless Philadelphia Style Ice Cream Works (+ Recipe)
Before reading ‘Hello, my name is ice cream‘ – which is a great book if you’d like to learn more about the science behind ice cream – I had never heard of Philadelphia-style ice cream. Also known as American ice cream, it’s an ice cream made without eggs, unlike its custard-based cousins.
Without the eggs it is said that this style of ice cream is firmer and chewier, but brighter in flavor. So, how does it work?
What is Philadelphia style ice cream?
Philadelphia style (or American, or New York-style) ice cream is an American type of ice cream, mostly used by Americans to describe a certain style. Elsewhere, that same ice cream may be called “cream ice cream” (literal translation from the Dutch ‘roomijs’) or it’s just ice cream.
That said, this name refers to a style of ice cream that’s made without any eggs or custard. Instead, you just mix your ingredients and freeze them.
Making Philadelphia style ice cream
The simplest way to make this type of ice cream is to mix cream, milk, sugars and possible some flavor and churn it in an ice cream machine. However, by adding just a few more steps you can add a lot of other flavours.
What happens when churning ice cream?
But before we dive into all the different flavours and processes, let’s look into churning. Churning is the step in ice cream making that transforms your liquid blend of ingredients (the ice cream base) into frozen ice cream.
You churn your ice cream in an ice cream machine. The ice cream machine both cools and moves the ice cream at the same time. Keeping the ice cream moving is essential for getting a soft ice cream. The movement will ensure air is incorporated into the ice cream. Air is important to keep ice cream light and easy to scoop.
Churning also ensures that your ice cream base stays a homogeneous temperature. If you would have put the liquid in a cold can you can imagine that the outside will cool a lot faster than the inside, ending up with an uneven freeze. By mixing the material on the outside with that in the inside continuously, that is prevented. Also, mixing will break up any possible ice crystals, ensuring a less gritty, more smooth ice cream.
Adding flavour to Philadelphia style ice cream
There are a lot of ways to add flavours to ice creams. You can add purees, syrups, pieces of cookies or chocolate for instance (as you will see in the recipe at the bottom of this post). A slightly more subtle way to add flavour though is by infusing some of the flavour into the milk and cream.
You can infuse flavour into these by heating them up and adding the ingredient that you want to infuse (e.g. vanilla beans, cinnamon sticks, nut meg). Because of the higher temperature, molecules move faster and those flavour molecules transfer into the milk and cream. Since cream contains quite a lot of fat, both molecules that dissolve well in water and those that dissolve well in fat, will move into the liquid mixture. If you would only use water a lot of flavour molecules might not be extracted well.
Why boil the cream and milk for Philly style ice cream?
You can make a perfectly fine ice cream by just mixing cream, milk and sugar and churning this in an ice cream machine. However, you will see that a lot of recipes still call for boiling the milk and cream on forehand, even though you don’t have to make a custard.
The aforementioned flavour infusion is one of the reasons to do this. It will help transfer flavour. Also, at these higher temperatures any sugar will dissolve a lot more quickly. Another important reason though, is one that may sound familiar to yogurt makers. Boiling them will denature the proteins causing them to unfold. Once proteins unfold, there will be sections that a hydrophobic, in other words, they don’t like sitting in water. Instead, they prefer sitting on some of that fat of the cream. This helps is making a better quality ice cream.
Chocolate ice cream (no eggs, Philadelphia style)
Yield:
at least 10 big scoops
Prep Time:
30 minutes
Cook Time:
45 minutes
Additional Time:
4 hours
Total Time:
5 hours 15 minutes
This recipe is based on one from the book Hello, my name is ice cream (a great book to learn more about the science behind ice cream). It's a super chocolatey, smooth, eggless ice cream, made in an ice cream machine.
Ingredients
- 100g dark chocolate
- 50g milk chocolate
- 20g cocoa powder (for that extra hit of chocolate!)
- 1/8 tsp salt (you can leave it out as well)
- 160g cream
- 450g milk (semi-skimmed)
- 50g corn syrup
- 20g milk powder
- 150g sugar
Instructions
- Break the chocolate into smaller pieces in a microwave-safe bowl. Melt the chocolate in the microwave by heating it for 30-60s intervals, mixing regularly to prevent burning.
- Once the chocolate has melted completely, mix in the cocoa powder and salt.
- Blend the sugar and milk powder in a bowl and put aside. Doing this helps ensure that the milk powder dissolves when added to the liquids later. Don't skip it.
- Bring the milk, cream, and corn syrup to a boil. Take care the milk doesn't boil over and doesn't burn at the bottom.
- Add the milk powder and the sugar to the boiling milk and cream and cook for another 1-2 minutes.
- Pour about 1/4 of the milk mixture in with the chocolate and whisk it through. It might be a little thick at the start but it will thin as you go.
- Add the remainder of the milk and cream mix.
- Cool the ice cream base. It is best to leave it in for a couple of hours before proceeding to the next step, though you could proceed as soon as is has cooled down (we explain why here).
- Churn the ice cream in your ice cream machine following its instructions.
- The ice cream will be quite soft when it comes from the machine. Place it in a freezer-proof bowl with a lid and leave to harden in the freezer.
- You'll be awarded with a great, scoopable ice cream!
Sources
David Lebovitz, The Perfect Scoop, 2011, p. 25, link
Philadelphia style ice cream based, NYT cooking, Melissa Clark, link
Hello, my name is ice cream, Dana Cree, 2017
On Food and Cooking, Harold McGee