Modernist Cooking Made Easy (8 page)

Fluid Gel Foams

An effective way to create thicker foams is by using gels and fluid gels. You first turn the liquid you want to foam into a gel. Often times agar, carrageenan, gelatin, or methylcellulose are used to create the gel, or fluid gel.

Depending on the ingredient, the gel can be whipped or put in a whipping siphon to create a foam. These foams have a range of textures and densities depending on the fluid gel used.

Agar fluid gels are usually made with a 0.25% to 1.0% ratio. Gelatin is used with a 0.4% to 1.7%. Xanthan gum can also be added to the above ingredients to thicken the foam, typically in a 0.1% to 0.4% ratio.

F
OAMING
E
QUIPMENT

There are many tools you can use to create foams and each one results in a slightly different texture. The purpose of all the tools is to introduce air into the liquid you are foaming. For tools such as whisks and immersion blenders you want to make sure part of the tool is out of the liquid so it will carry air into the foam.

Whisks, Manual and Electric

Whisks are a great way to create dense foams as well as some lighter foams. Manual whisks can get the job done but using an electric whisk attachment greatly speeds up the process and tends to form finer foams. The whisk attachment can be on an immersion blender or a standing mixer.

Standing or Hand Held Mixer

Mixers without a whisk attachment can also be used. They can create lighter foams very efficiently.

Milk Frother

A milk frother is an inexpensive tool that is used to create foam for cappuccinos or lattes. When it used with modernist ingredients it can create similar foams from other liquids. Aerolatte brand frothers are usually under $20.

Immersion Blender

Immersion blenders are good at creating airs and other light foams. Ensuring part of the blade is out of the liquid is critical. A traditional standing blender will not work well for foaming because the blades are completely submerged.

Whipping Siphon

The whipping siphon is an awesome tool for making foams of all kinds. It is a container you fill with liquid and then pressurize with NO
₂
or occasionally CO
₂
. They are very effective at creating foams and also help in the storage of liquids you will be foaming over time.

Aquarium Bubbler

An aquarium bubbler is one of the more unusual ways to create foams. It works well for creating large bubbles, similar to soap bubbles. Tetra Whisper brand pumps can typically be found for under $10.

L
IGHT
F
OAMS

Light foams can be airy, coarse foams or wet, fine foams. They are also the easiest to make without additional kitchen equipment like a whipping siphon or standing mixer.

You can make light foams in a few different ways but either an immersion blender or electric whisk works well, as do milk frothers or aquarium bubblers for specific types of foams.

To make a light foam you combine the liquid you want to foam with the foaming agent. For light foams the foaming agent is typically lecithin, sometimes with some xanthan gum added to create wetter froths.

Once the foaming agent has been incorporated you add air to the liquid through whipping or blending. If you are using an immersion blender you want to keep half of the blade out of the liquid so the maximum amount of air will be introduced.

Depending on the liquid and foaming agents used, the light foam will last for 30 to 60 minutes. However, it will lose body the longer it sits.

You can spoon the light foam directly onto a dish or freeze it for a cold, ethereal treat.

Light Foam Ratios

At the dryer end of the spectrum, most airs use 0.25% to 1.0% lecithin, though the specific amount isn’t as important as in many other techniques.

For wetter foams, xanthan gum can be added at 0.1% to 0.4%. The more xanthan gum added, the wetter the foam will tend to be.

For bubbles, resembling soap bubbles, a typical ratio is 0.1% to 0.4% xanthan gum and 0.2% to 2.0% Versawhip or egg white powder.

S
OY
A
IR

Airs are typically dry, coarse foams that are mainly made up of air. Strongly flavored liquids should be used in airs because they have such little liquid. Here we used soy sauce which adds a salty, umami flavor to dishes. This recipe can be used with most liquids to create airs.

This soy air is a great garnish for Asian flavored tuna or pork.

Tools Needed

Lecithin

Immersion blender

Flat bottomed, wide container

A scale with small gram measurements

Ingredients

125 grams water

125 grams soy sauce

8 grams sugar

1 gram lecithin, 0.4%

Combine the water, soy sauce, and sugar in a sauce pan. Bring to a simmer while whisking occasionally to break up any lumps. Remove from the heat and blend in the lecithin with an immersion blender.

Pour it into a wide, flat bottomed, container. You can set the soy sauce mixture aside like this for several hours.

When ready to serve, blend the soy sauce mixture using an immersion blender until a nice head of foam develops. While blending try to keep the immersion blender halfway out of the liquid so it will incorporate as much air as possible.

Let the soy foam sit for 1 minute to stabilize and then spoon it out onto your dish.

O
RANGE
F
ROTH

This orange froth is a good way to add a different texture to a dish, as well as an interesting visual component. It is wetter than an air but still very light.

It can be used on tropical salads or as a sauce for white fish. It is also good on desserts or fruit salads. If you enjoy mimosas this can be a unique way to add the fruit juice to it as well. It can also be used as an amuse bouche between courses, especially if you use a whipping siphon to foam it.

Tools Needed

Lecithin

Xanthan gum

Immersion blender

Flat bottomed, wide container

A scale with small gram measurements

Ingredients

250 grams orange juice, preferably fresh

1.8 grams lecithin, .75%

0.75 grams xanthan gum, 0.3%

Strain the orange juice if it has a lot of pulp since it will inhibit the formation of bubbles.

Place the orange juice in a container that works well with your immersion blender. Sprinkle in the lecithin and xanthan gum and blend to combine well. Pour into a wide, flat bottomed container. You can set the mixture aside like this for several hours.

When ready to serve, blend the orange juice mixture using an immersion blender until a nice head of foam develops. Try to keep the immersion blender halfway out of the liquid so it will incorporate as much air as possible.

Let the orange froth sit for 1 minute to stabilize and then spoon it out onto your dish.

G
RAPE
B
UBBLES

These bubbles are large and visually interesting. They also carry a surprising amount of flavor. I originally wanted to make these to use with a peanut butter panna cotta for a take on a PB&J but it can be used on many different dishes. You can also substitute the grape juice for just about any other fruit or vegetable juice.

Tools Needed

Versawhip

Xanthan gum

Immersion blender

Aquarium pump with plastic hose

A scale with small gram measurements

Ingredients

400 grams grape juice

2.0 grams Versawhip, 0.5%

1.0 grams xanthan gum, 0.25%

Combine the grape juice with the Versawhip in a narrow, deep container and blend with the immersion blender to combine. Add the xanthan gum and blend until it is evenly distributed. You can set the mixture aside like this for several hours.

When ready to serve, connect a clean piece of plastic hosing to the aquarium pump and place the other end in the mixture. Turn on the pump and let it create bubbles until there are enough for you to use.

Let the bubbles sit for 1 minute to stabilize and then spoon them out onto your dish.

R
ASPBERRY
Z
INGER
F
OAM