Three cocktails with orange garnish and foam

Foams vs Airs Part I

The Science Behind It & How to Execute.

Drinks like these wouldn’t look or taste the same without their fluffy aerated consistency, which is why bartenders have been experimenting with flavoured foams and airs over the recent decades.

Estimated reading time: 15 minutes

Could you imagine a cappuccino without its froth? Or a Guinness without its creamy head? Or how about a Ramos Gin Fizz made without any heavy cream or egg white? Drinks like these wouldn’t look or taste the same without their fluffy aerated consistency, which is why bartenders have been experimenting with flavoured foams and airs over the recent decades. It has become an easy way to add unique aromas, textures, flavours, and visual wow factors to create multi-sensorial experiences.

Foams and Airs can take cocktails to interesting new levels that separate themselves from the ordinary classics that you can find in most bars, providing guests with something new and exciting to experience.

What are foams and airs?

Foams and Airs are both aerated liquids that have been whipped with a fat or stabiliser to keep their fluffy texture holding for a long duration of time.

A foam will have a creamier consistency similar to frothed milk, while an air will be more similar to the bubbles created like soap in a bathtub. The size of the bubble depends on the stabiliser that you are using, as well as the equipment used to incorporate air into it.

TOOLS FOR FOAM CREATION

  • Siphon (for whipping or cream)
  • N20 Cartridges
  • Stabilising agent (see list below)

By far the most efficient way to make a foam is with a siphon and a couple of N20 (nitrous oxide) cream cartridges. Using N20 cartridges with a siphon forces the nitrous oxide gas into the liquid, whipping it at a rapid speed and transforming it into a foam. Filling a siphon to its full capacity will usually require two N20 cartridges.

STABILISING AGENTS

Stabilising agents serve as a thickening agent in the liquid to keep your foam or air bubbles together. They require experimentation to find the right ratio for the textures you are trying to create. Egg whites, albumin, agar-agar, gelatin and versawhip are some of the most common stabilisers to use in serves. 

Egg White or Albumin

Pros

  • Egg white will give a mousse-like texture to the foam which perhaps works best with cocktails. It’s one of the most stable and fluffy foams that is easy to execute.
  • A good alternative to use is albumin which is powdered egg. It will achieve the same result without adding dilution to the foam.

Cons

  • Using fresh egg whites will contribute to the dilution of the drink as well as the volume, which means that your recipe will have to be readjusted unless you use albumin. It’s also not vegan-friendly.

Use

  • Between 3 to 15% of the total volume of liquid when using egg white.
  • Between 1 to 3% of the total volume of liquid when using albumin.

Agar-Agar

Pros

  • Agar-agar is a plant-based gelatin that comes from seaweed making it vegan-friendly.
  • The foam can also be heated up by being kept in a warm water bath and topped up onto hot cocktails.
  • It has a higher tolerance for acidic ingredients as well as alcohol.

Cons

  • The foam from agar-agar won’t have as much of a firm and stable texture as the others mentioned.
  • It also needs to be heated with your chosen liquid at 85C/185F before being charged.
  • In addition, heating your liquid will alter your final flavour.

Use

  • Between 0.1 to 0.5% of total volume of liquid.
  • Activate liquid at 85C/185F.

Gelatin

Pros

  • Gelatin is usually animal-based and made from livestock collagen.
  • Using them will create very stable and elastic foams that have a great texture to them with no additional flavour, even less so than the others mentioned.
  • It can also hold up to solutions of up to 30% ABV.

Cons

  • Gelatin is not vegan-friendly.
  • It requires heating the liquid up to 60C/140F before being charged.
  • It does not hold up well to highly acidic solutions.

Use

  • Between 1 to 5% of the total volume of liquid.
  • Activate with liquid at 60C/140F.

Versawhip

Pros

  • Versawhip is a pure enzymatically treated soy protein making it vegan-friendly.
  • It has a similar mousse-like texture and is the best alternative to egg white/albumin foams.
  • It doesn’t require any prior heating to activate.

Cons

  • Contains soy allergy.

Use

  • Between 0.5-2% by weight of total liquid.

How to Make a Foam

1. Pick your stabiliser

  • If you are using egg white, albumin or versawhip, combine it with your chosen liquid with a whisk or better yet a blender, making sure that they are completely combined.
  • If you are using gelatin or agar-agar you will first have to heat it together with your chosen liquid to the respective temperatures mentioned above. Make sure to blend them until fully combined.

2. Once combined, pour everything into the siphon and close it

  • Charge the siphon with the first N20 cartridge and shake vigorously for 5 to 10 seconds, just to ensure that the gas is combining itself with the entire surface of the liquid.
  • You can then charge the siphon with the second cartridge and shake it again for another 5 to 10 seconds.
  • Place the siphon in the fridge for at least 20 minutes before using.
  • This will help the liquid firm up and be cold until ready to use it.

Beetroot Foam Recipe

Ingredients

  • 475ml beetroot juice
  • 2.5g-5g albumin or versawhip

Method

  1. Juice the beetroot and combine with stabiliser in round container.
  2. Blend or whisk together until fully combined. 
  3. Charge with 2 cartridges of N20 in a siphon.
  4. Let sit for 20 minutes in the fridge and apply on the finished cocktail.

This is the perfect cocktail foam to add to a Johnnie Walker Penicillin.

TOOLS FOR AIR CREATION

Using a Siphon makes it more difficult to achieve the light foamy texture of an air and will require a set of different sets of equipment. You'll need:

  • Emulsifying Agent (see list below)
  • Immersion Blender
  • Fish Bubbler (optional)
  • Aerator or Milk Frother

Emulsifying Agents

Different emulsifying agents produce difference results. The easiest to get started with are Soy Lecithin and Sucrose Esters. These are inexpensive and easily purchasable online.

SOY LECITHIN & SUCROSE ESTERS

Soy Lecithin

  • Derived from soybeans, and helps stabilise the bubbles to create a stable foam.
  • Is typically added to the liquid in a ratio of around 0.5% to 2%, depending on the desired level of foam.

Sucrose Esters

  • The bubbles you can get are lighter and the air frothier than when using Soy Lecithin.
  • Sucrose ester will froth up in the presence of alcohol easier than Soy Lecithin, so if you wanted to add a liqueur to your air, this would foam easier. 

How To Make a Cocktail Air

1. Pick your emulsifier and combine

  • Whether you are using soy lecithin or sucrose esters, combine it with your chosen liquid by using an immersion blender. This will trap air into the liquid. 

2. Use with an aerator to produce bubbles

  • To get the maximum results, you will then use the aerator (preferred) or milk frother.
  • This will give you more yield of air as well as make it last even longer.
  • Gently scoop out the bubbles out and place them on your drink - a julep strainer works great for this.

Tomato Air Recipe

Ingredients

  • 475ml tomato juice
  • 5g soy lecithin

Method

  1. Juice the fresh tomatoes and let sit in a chinois with a coffee filter.
  2. Collect the clarified liquid and combine it's total weight with 1% of soy lecithin (5g)  
  3. Combine with an immersion blender.
  4. Use an aerator or frother to produce stable bubbles
  5. Gently scoop out the bubbles out and place them on your drink - a julep strainer works great for this.

Try topping this tomato air on a Tanqueray Flor de Sevilla Negroni.

Key Takeaways

  • Foams and Airs are great ways to add texture and additional flavours to a cocktail without changing what goes into the actual liquid.
  • It’s important to make sure that the air or foam on top of the drink complements the actual liquid inside of the glass. Its purpose is to make something that’s already good even better.
  • Use the stabiliser that will create the best result for what you’re trying to achieve.
  • Always keep in mind the allergies and dietary restrictions of your stabilisers.

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