Hot Ice Cream Molecular Gastronomy Science Project

Hot Ice Cream
Hot ice cream is a hot solid treat that melts as it cools. The key ingredient is methylcellulose.

Have you ever wondered what it would be like to have a scoop of hot ice cream that doesn’t turn into a melted mess on a hot summer day or that warms you up in winter? Thanks to the marvels of molecular gastronomy, it’s easy making hot ice cream that solidifies when heated and melts as it cools. This culinary wonder works because of an ingredient called methylcellulose, a food additive that is quite magical in the world of food science.

What Is Methylcellulose

Methylcellulose is a type of cellulose, a naturally occurring polymer found in plant cell walls. When used in cooking, it acts as a thickener, emulsifier, and stabilizer. The unique attribute of methylcellulose is its thermo-gelation property: it gels or thickens when heated and liquifies when cooled, which is the opposite of many traditional gelling agents. It’s in a variety of foods from vegan burgers (to bind ingredients together) to making airy, foamy textures in high-end cuisine. It’s also the secret behind how bakers get liquid ingredients inside baked goods without making a mess.

Now, let’s dive into the world of molecular gastronomy to make some hot ice cream. We’ll start with a classic vanilla flavor, then switch things up with a rich hot chocolate version.

Vanilla Hot Ice Cream

At its heart, a hot ice cream recipe is just like a normal ice cream recipe. You can substitute ingredients and make vegan ice cream with plant-based milk. Any flavoring is fair game. The adjustment is adding methylcellulose and altering how you solidify the product.


  • 200 ml (1 cup) of whole milk
  • 100 ml (1/2) of heavy cream
  • 50 grams (1/4 cup) of sugar
  • 1 vanilla bean
  • 4 grams (1 teaspoon) of methylcellulose


  1. In a medium-sized saucepan, combine the milk, heavy cream, and sugar. Split the vanilla bean and scrape out the seeds, adding both the seeds and pod to the saucepan.
  2. Heat the mixture over medium heat until the sugar fully dissolves and the mixture is steaming hot, but not boiling.
  3. Disperse the methylcellulose in the hot mixture, using a whisk or immersion blender to ensure it’s fully incorporated without lumps.
  4. Let the mixture cool to room temperature and then remove the vanilla pod.
  5. Place the mixture in the fridge and let it cool completely, ideally overnight. The mixture liquifies as it cools.
  6. When you are ready to serve the ice cream, heat a pot of water to boiling. Using a ladle or ice cream scoop, take a scoop of liquid. Wipe an excess liquid off of the outside of the scoop. Lower the scoop into the water into the water, wait 3 to 5 seconds so the ice cream firms, and then tilt the scoop and release the ice cream into the water. Let it cook for a minute or two until it feels firm. Remove the cooked ice cream using a slotted spoon. Briefly place it on a paper towel to absorb excess water and then serve it in a bowl or ice cream cone. Add whipped cream, sprinkles, or other toppings, if desired.

Hot Chocolate Ice Cream

Here is the same process, except you get comforting hot chocolate ice cream!


  • 200 ml (1 cup) of whole milk
  • 100 ml (1/2 cup) of heavy cream
  • 50 grams (1/4 cup) of sugar
  • 30 grams (1 ounce) of dark chocolate, finely chopped
  • 4 grams (1 teaspoon) of methylcellulose


  1. In a medium-sized saucepan, combine the milk, heavy cream, and sugar.
  2. Heat the mixture over medium heat until the sugar fully dissolves and the mixture is steaming hot, but not boiling.
  3. Remove from heat and add the chopped chocolate, stirring until fully melted.
  4. Sprinkle the methylcellulose over the hot mixture and whisk it or use an immersion blender to ensure it’s fully blended.
  5. Let the mixture cool to room temperature.
  6. Place the mixture in the fridge and let it cool completely, ideally overnight.
  7. To serve, immerse a scoopful of liquid in a spoon or ladle in boiling water. The mixture thickens into the consistency of ice cream as it heats. Serve immediately and watch as it slowly melts while it cools.

Adjusting the Recipe

There is a typical range of methylcellulose concentrations commonly used in culinary applications, especially when making hot ice cream.

The general guideline for methylcellulose is around 0.5% to 3.0% by weight of the liquid for most recipes. This depends on the specific grade of methylcellulose being used. For these hot ice cream recipes, the methylcellulose concentration is around 1.5%, which falls within this typical range.

Lower concentrations (<0.5%) don’t provide a strong enough gel to form a scoopable ice cream when heated. Instead, you end up with a mixture that thickens slightly but remains more of a sauce or custard in consistency. On the other hand, using a high concentration (>3.0%) results in a gel that is too firm or even rubbery when heated.

Like with many aspects of cooking and especially with molecular gastronomy, you may need some trial and error to get the result you’re looking for. So, adjust your recipe by adding either less or more of the ingredient if you want to change the firmness of your ice cream. Experiment with your recipe and see if you can think of fun new ways of using hot ice cream or solidifying other liquids!

How Methylcellulose Works in Hot Ice Cream

Methylcellulose chemical structure

Methylcellulose’s properties seem a bit counterintuitive compared to many substances we’re familiar with in the kitchen.

Methylcellulose forms a gel when heated and dissolves when cooled is due to its unique chemical properties. As a derivative of cellulose, methylcellulose is a long-chain polymer with hydrophilic (water-loving) and hydrophobic (water-repelling) regions.

At cooler temperatures, the hydrophilic regions interact favorably with water, resulting in a liquid or semi-liquid consistency. However, as the temperature increases, the hydrophobic interactions become more prominent. This results in the methylcellulose chains bundling together and excluding water, forming a gel-like structure. This process is called thermo-gelation.

It’s also important to note that methylcellulose has what’s known as a critical gelation temperature, above which it forms a gel. This temperature depends on the specific type of methylcellulose and its concentration in the mixture. In cooking applications, this temperature is usually around 40-50°C (104-122°F) for the gel formation to start and it strengthens as the temperature rises, usually peaking around 60-70°C (140-158°F).

So, to create hot ice cream, we take advantage of these properties by dispersing the methylcellulose in a hot mixture, allowing it to cool (and hence dissolve), and then reheating it to above its critical gelation temperature to form a scoopable gel or ‘ice cream’. As the heated gel cools back down, the gel breaks down and the ice cream ‘melts’.

In essence, this is a rather unusual play on the traditional behavior of materials which are solid at room temperature and melt upon heating. Methylcellulose, on the other hand, is a unique substance that provides this fascinating and fun culinary twist.


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