How to Cook Like Heston – What You Should Know

Effervescence

  • Foaming or the fizziness that results from the release of gas in the food.
  • Why fizzy tastes fizzy? – Painresponse to CO2. CO2 bubbles burst on our tongue resulting in a tingling pain sensation and heightens other sensations
  • Popping Candy - Sugar containing trapped CO2. When sugar melts or is bitten into, the gas is released with popping effect.Can be added to a variety of dishes for a fizzy or popping affect.
  • Honeycomb - Bicarb Soda reacts with hot sugar to make CO2 bubbles

2xSodium Bicarbonate molecules break down with heat to form 1xSodium carbonate molecule, 1xCarbon Molecule and 1xWater molecule (2NaHCO3) --> Na2CO3 + CO2 + H2O)

The gas causes the bubbles in the mix and as the sugar cools and hardens the bubbly texture remains

  • Sherbet - Citric acid (an acid) and Sodium bicarbonate(a base).

Base definition: A chemical species that donates electrons/hydroxide ions, or accepts protons (basically, the opposite of an acid)

Reactions generally can’t occur when both reagents (the powders) are solids

The powder must dissolve in your mouth to allow the reagents to move around and react with each other

Sodium Bicarbonate + Citric Acid --> Sodium Citrate (antacid) + Carbonic Acid (carbonic acid is such a weak acid that it spontaneous falls apart) --> Water + Carbon Dioxide

Spherification

  • Encapsulates flavours into bubbles that burst in your mouth, using sodium alginate & calcium salts to forms a gel casing
  • Sodium Alginate is made up of long molecules that look like zigzags. The moleculesare flexible and move freely when dissolved in water.
  • The sodium alginate solution isdropped into a bath with calcium ions floating around. The long molecule threads are attracted to each other by calcium ions and create a structure that resembles a box of eggs.
  • Gel formation involves a rearrangement of the molecules that align and attach themselves until they form a network that traps the liquid.This network looks like meshes of a net that keep all of the particles in suspension, preventing the collapse of the structure.
  • Basic Spherification - A solution containing sodium alginate is poured into a high-calcium bath. Calcium ions migrate towards the solution to be spherified and then trigger the membrane’s gelification.
  • Reverse Spherification - A solution containing calcium is immersed in a high-sodium alginate bath. Calcium ions migrate from the sphere’s interior to its exterior, thus forming a gel wall.

Gelification

  • Formation of a gel from a liquid, a change from liquid to solid state and involves rearrangement of molecules.
  • Gel texture can range from supple and elastic to firm and brittle depending on type of additive.Traditional: traditional are found everywhere: flours, tapioca or corn starch, eggs and gelatin. Molecular Gastronomy: hydrocolloids: Carageenan, Agar-Agar
  • Hydrocolloids make it possible to form gels when it otherwise wouldn’t be possible.

Hydro – dissolves in water

Colloid - a substance microscopically dispersed throughout another substance

  • The hydrocolloid particles dispersed in water detach from each other, and liquid moves into and swells the molecule, and it hen dissolves. Complete dispersion allows gelling agent molecules to be completely surrounded by water.Improperly dispersed gelling agent will form lumps.
  • Once hydrated, the long molecules no longer have any defined structure and are rather randomly organized in the solution
  • As the solution cools, the polymer chains twist together and form double helices with other molecules while bonding one molecule to another. They form a network that traps the liquid.This network looks like meshes of a net that keep all of the particles in suspension, preventing the collapse of the structure.
  • A weak bond between the molecules will result in softer, more elastic gels. A strong bond between the molecules is created when multiple links are formed between the double helices. The resulting gel will be firmer and more brittle

Review Questions

1. How are particles or molecules involved in the molecular gastronomy techniques;effervescence, spherification and gelification?

2. Describe the chemical reactions that are involved in

effervescence

spherification

3. How are molecules or atoms rearranged to form new substances in the techniques discussed?

4. How are different chemical reactions used to create different products?

5. Describe the differences between the chemical reactions and how they occur.