Simple ice cream – Semifreddo

Yes, I know, it’s winter, and winter probably isn’t the best time to eat ice cream. But what about a nice bowl of ice cream while you’re sitting on your couch under a blanket, watching the cold weather outside? Sounds pretty good isn’t it? (Especially if you manage to combine with a warm piece of pie….)

How to do that without leaving the house? Simple, make it yourselves! And to start easy, here’s a recipe and technique that works without an ice cream machine and makes great ice cream.

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You know what’s even better about making and eating ice cream? Looking at the sciency bits of ice cream, yes! So of course, after sharing the recipe, let’s dive into ice cream science.

A semifreddo is what I made. Semifreddo is Italian for ‘somewhat’ cold. And that’s just what it is. It’s a cold (because frozen) dessert, however, doesn’t taste that cold at all. What’s more, it’s very easy to make and easy to explain!

So how did I find out about semifreddos? Again, it’s through my all time favourite TV show Masterchef Australia. In this cooking show, contestants have to cook fabulous meals in short amounts of time. It just happens that this type of ice cream is made oretty often, because it’s easy and fast.

The recipe I used came from ‘De Zilveren Lepel‘, an Italian cookbook.

Fruity semifreddo
 
Author:
Ingredients
  • 6 eggs
  • 250g sugar
  • 250g blue berries
  • 750 ml of whipping cream
Instructions
  1. I made ⅓ of the recipe, which is more than enough to serve at least 6 people I find. I posted the large amount since 250/3 doesn't give a nice number...
  2. Whisk the eggs and sugar together
  3. Heat au-bain-marie above a pan of boiling water. Keep on whisking continuously (you don't want the egg to cook at the sides) until you can see the mixture has thickened. The temperature will have to be around 70C.
  4. Remove the mixture from the heat, keep on whisking for some time to prevent it from cooking futher on the sides.
  5. Whip up the cream and use a spatula to mix this with the sugar + egg mixture
  6. Mix in fruit gently.
  7. Pour into a mould (for example a cake tray) which has been covered with plastic foil. Cover the mixture with the foil entirely and freeze.

Air in ice cream

It’s easy to make, so while your ice cream is setting in the freezer (or while you’re waiting to make it). Let’s dive into ice cream science, we’ll start with air. In order to make a good ice cream, you will need to introduce air. Just have a look at your store bought ice cream, the pack will probably say there’s a certain volume in there. However, if you’d leave it to melt, you’ll see that that volume has shrunk a lot once it’s all melted.

Air is essential for making a good ice cream. First of all, it allows you to scoop ice cream. The air bubbles will make it easier to scoop through your ice cream. Furthermore, it will make ice cream taste ‘lighter’ and airier. Just imagine freezing a pack of cream (upwhippd) it’ll be one hard block, impossible to scoop and eat properly.

In a semifreddo air is incorporated in an easy manner. You whip up cream to introduce air in the cream. By carefully folding in this whipped cream with the other ingredients, you’ll introduce air. So be careful when you’re folding it in, it’ll influence the texture and taste sensation.

It is important to freeze your semifreddo as soon as its finished. The air bubbles aren’t that stable, so they will leave the mixture if you leave it on your counter.

sugar + eggs, ready for the double boiler

Heating eggs & sugar

By heating the sugar with eggs over hot water you will cook the eggs gently. By heating them the proteins will denature (see my infographic on eggs) and they will thicken up the mixture. This thick mixture will ‘catch’ water. When freezing, this water cannot form large ice crystals. Which is good, you don’t want large chunky crystals in your ice cream. This way you can also prevent melting of the ice cream and it will give a creamier structure.

Eggs also play an important role because of the fat in the eggs. Together with the fat from the cream, they make the ice cream taste more creamy.

Freezing water & sugar

Essentially, all ice creams (even very simple lollipops) are frozen water with sugar. Besides the fact that sugar gives the ice cream a nice taste, it is also very important for making an agreeable ice cream. Think about the difference between an ice cube from your freezer and a frozen syrup. The ice cube will be very hard, whereas the frozen syrup is a lot softer. Why is this?

It’s a great showcase of the phenomenon ‘freezing point depression’. By adding sugar to water, the freezing point of the solution will decrease. So instead of the water freezing at 0°C, it will freeze a few degrees lower. Then, when part of the water in the ice cream freezes, the other part of the sugar solution will be even more concentrated. The freezing temperature will be even lower. In the end not all the water has frozen!

 

Good luck trying out the semifreddo. I do have an ice cream machine at home as well and love to use it. So keep coming back for different ice cream posts!

 

 

Sources & Notes

Do note, when not heating/pasteurizing eggs properly, you could run a risk for Salmonella. So keep this in mind when making homemade ice cream, don’t take the risk if you don’t trust it.

Want to read more about ice cream? Serious Eats wrote a great post about it!

2 Comments

    • Hello Mark,
      Thank you for visiting! Regarding your question, it’s a little hard to answer if I don’t have a recipe, but I’ll give it a shot. There are a couple of reasons the ice cream may stay very soft:
      – Not cold enough: it sounds strange, but ice cream really needs time in the freezer to harden. In will remain soft for several hours. Leave it in the freezer (-18C) overnight to make it hard.
      – It’s mostly the water & fat that will harden in the freezer, it’s the sugar & air that will keep a semifreddo soft. If you’ve added too much air & sugar that might make it softer.
      – It has split, when the separate components aren’t stable, the fat & liquid might sink to the bottom whereas the very light airy bit stays on the top. This will result in a very hard & dense bottom and a super soft top. Prevent this by mixing the three elements well (but gently).
      – When making a semifreddo with these three components, all three have to be made well, which can be tricky. Make sure the cream has been properly whipped, so it’s firm and stable. Assure the Swiss meringue doesn’t collapse (that might give a soft top and very hard bottom) and assure the zabaglione has thickened up well (heat those egg yolks enough, but don’t let them curdle).
      Hope it helps and good luck with your next attempt!

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