If adding chemicals to your food takes you back to the hyper-colour days of 70’s and 80’s dinner parties, then you’re not alone. For many, food additives conjure visions of allergic reaction and long term ailment, but in reality not all food chemicals are bad and many of our favourites would be flavourless, textureless and joyless without them. 

Take as two strong examples of the power of molecular gastronomy, Heston Blumenthal and Adrianno Zumbo, who were skyrocketed to fame through their unconventional use of techniques and food additives. Time and time again we have served customers here at Essential Ingredient, who in attempting to follow in their footsteps, cannot find the maltose, sodium hydrochloride, and calcium chloride that are the foundation of these pairs sensational recipes. Unfortunately we suffer from the same ailment of being unable to source a comprehensive range of these products in retail quantities for our customers, so in an attempt to assist you in other ways we now write this guide on where to find, how to use and what to expect from your molecular gastronomy ingredients and techniques.

Hydrocolloids

Commonly referred to as gelling agents, this family includes pectin, gelatine, agar agar, kuzu, corn starch. Each of these has a different melting point and therefore requires that each be prepared differently.

Gelatine is the most easily sourced of these and can be used in a range of foods from Jams to savoury aspics. Gelatine is available in gold and titanium strengths with titanium merely being a stronger composition of the same components found in the gold. The preparation process for hot mass involves soaking the leaves in cold water until they become soft then combining them with simmering liquid ingredients until dissolved. For cold mass the soaked leaves must be dissolved over heat then the cold mass added slowly and stirred until completely combined

A general ratio between gelatine and liquid mass follows:

Firm or Standard Jelly: 7 grams of gelatine to 250ml of liquid mass
Tender Jelly: 7 grams of gelatine to 500ml of liquid mass
Trembling or Delicate Jelly: 7 grams to 750ml of liquid mass

 Desserts that contain gelatine are best chilled for a minimum of 8 hours although a full 24 hours is ideal.

 According to Harold McGee and other notable chef’s you should not use spices or fresh fruits in your jellies unless they are fully cooked beforehand. These ingredients contain protein digesting enzymes that attack the gelatine and prevent it from setting.

Agar agar is a plant based alternative which comes in the form of powder or leaf. It can be dissolved in boiling water and has a much higher melting point than gelatine, making it more stable at elevated room temperatures. Agar agar is comprised of around 90% fibre, which means it is able to absorb far greater amounts of water than gelatine for a more firm feel in the finished product.

Agar based sweets develop a more brittle consistency and must be chewed as they do not break down with the heat of the mouth. For finished produced to melt it must be exposed to temperatures of 85°C

Like gelatine fresh fruits and spices cannot be used with agar powder or leaf as the same breakdown occurs

Agar to Liquid Volume Ratio: 2 Teaspoons of agar agar powder will set 500ml of liquid mass

Pectin is another plant based setting agent that when mixed with fruits or dairy products will create a gel as opposed to a jelly. It is often used in jams to reduce the amount of sugar needed for the jam to set as its soluble fibre components create a stable structure through absorption of fluid. There may be sufficient levels of pectin in some fruits meaning that the addition of a powdered pectin is not necessary. However most jam components such as berries and tropical fruits do not contain the levels required for a natural setting process to occur.

The following table contains a list of groups to help you establish which fruits require added pectin and which ones don’t.

Group I: If not overripe, contains enough pectin to naturally set
Group II: May require some added pectin to set
Group III: Almost always requires added pectin to set

Use: 2.5g – 3g of pectin to every kilogram of fruit.

Kuzu is derived from the kuzu plant and has similar thickening properties to corn starch or arrowroot. It is a common component in Asian cooking, being used in dishes from sweets to soups and broths. The texture of kuzu is much finer than other starch thickeners creating a creamy rather than sticky result.

Use approximately 1-1/2 tablespoons of kuzu per cup of liquid for sauces and gravies and 2 tablespoons per cup for gelling liquids. For most preparations, completely dissolve the measured amount of kuzu in a little cold water, then add it to the other ingredients near the end of cooking time. Gently bring the mixture to a simmer, stirring constantly while the kuzu thickens and becomes translucent.

Cornstarch is a highly refined low protein thickening agent. It is popular in American cooking, but is not used widely in other parts of the world. It is suitable for use in pastries and also pastas, but alternative ingredients and techniques can be used to avoid its use. We do not recommend the use of corn starch due to the high levels of chemicals required for its production.

Cornstarch is relatively easy to use as a thickening agent. There is no set ratio for combining corn starch with liquid. Simply create a mixture of corn starch and water until it forms a paste. Add the starch to the liquid until an acceptable consistency forms.

More natural alternatives to cornstarch are arrowroot or potato starch.

Gelatine in both titanium and gold strength, agar agar leaves and powder, citrus pectin and kuzu are all available from Essential Ingredient Rozelle. Most supermarkets will carry cornstarch in the form of cornflour.