Molecular Gastronomy – Science in The Kitchen
Molecular gastronomy is a sub discipline of food science that seeks to investigate the physical and chemical transformations of ingredients that occur in cooking. Its program includes three axis, as cooking was recognized to have three components, which are social, artistic and technical. Molecular cuisine is a modern style of cooking, and takes advantage of many technical innovations from the scientific disciplines. The term “molecular gastronomy” was coined in 1988 by late Oxford physicist Nicholas Kurti and the French INRA chemist Hervé This. For the purpose of this course, we use molecular gastronomy as a term to describe our pursuit as plant based culinary science enthusiasts, to treat our ingredients in certain ways with a certain attitude using certain techniques which are all low temperature ultimately to achieve incredible flavour, nutrient bio availability, with easy digestibility, aesthetically pleasing, creative and artistic all this without cooking and preserving the integrity and nutritional profile of the ingredient and mostly enhancing the nutritional profile. There are a number of techniques that really help in this pursuit, all techniques must share the vision of breaking down the cell wall of vegetables and fruits to release amazing flavours – much of this is often destroyed by cooking. These techniques not only break down the cell wall but enhance the ingredient, elevating a humble vegetable into a Michelin star dish. Some of these techniques we have already covered such as blending, juicing, fermenting, pickling, dehydrating and slow cooking.
Raw Foods are not just uncooked foods, raw foods are not just cold foods. Raw Foods can be warm, slow cooked and must always be organic, unprocessed, loaded with easy to absorb nutrients and prepared in a unique way to ensure maximum absorption of high quality nutrients, pyhtonutrients, minerals, healthy fats, amino acids and enzymes. This is not an alternative health or diet strategy. This is about optimum elite health in mind and body. This is about incredible energy and vitality and about investing in your future mind and body health to prevent age, diet & lifestyle related illness and inflammation.
Other techniques we will now explore are:
“Raw vegan food is not boring salads and uncooked vegetables, raw food is a culinary pursuit, a dedication and endeavor to transforming the highest quality of vegetables using simple techniques to extract exquisite flavors, preserving the essential nutrients and enzymes and complementing them with an array of mineral rich nuts, seeds, seaweeds, sprouts and fruits. Raw vegan food is the pursuit of perfect food, art for the eyes, a taste of naturalness, unparalleled nourishment for the body and great for the planet too” – Plant Based Academy
“What is Molecular Gastronomy?A field that “attempts to link chemistry to culinary science, to explain transformations that occur during cooking, and to improve culinary methods through a better understanding of the underlying chemical composition of food” (Roudot 2004)
In 1969 Professor Nicholas Kurti, Hungarian from origin but Professor of Physics at Oxford University since 1967, gave a talk at the Royal Society titled “The physicist in the kitchen”, amazing the audience by using the recently invented microwave ovento make a “reverse Baked Alaska”, which was cold outside but hot inside (Sanders, 2000). Later, in 1988, began the movement that gave rise to the branch of science called ‘Molecular Gastronomy’, when Nicholas Kurti, and a French chemist, Hervé This, initiated a collaboration with the aim of studying the chemical and physical processes that occurred during the seemingly banal act of cooking. This has shown that many of the phenomena in cooking could be explained scientifically based on food composition and physical and chemical changes occurring during food preparation. Another of the important names related to molecular gastronomy is undoubtedly Harold McGee, author of books like “On Food and Cooking” dated from 1984 or “The Curious Cook: More Kitchen Science and Lore” from 1990, and co-organizer of the groundbreaking 1992 Erice Workshop on molecular gastronomy.
“What is Gastronomy? Gastronomy in the intelligent knowledge of whatever concerns man’s nourishment…” From the Ancient Greek words gastros meaning ‘stomach,’ andnomos meaning ‘law’ or ‘knowledge’Generally the study of the relationships between food and culture using interdisciplinary approaches -(1825, Physiology of Taste)
Molecular gastronomy is distinguished from traditional food science because the object of study is the preparation of food in small scale rather than large scale (industrial). But more than that, the molecular gastronomy treats food as a whole: the ingredients, following preparation and finally how food is appreciated by consumers. It is therefore a highly interdisciplinary subject involving physics, chemistry, biology and biochemistry, but also physiology and psychology. Molecular gastronomy is a culinary trend created by the cooperation of chefs and scientists and it has been defined as the scientific study of deliciousness. Mistakenly seen as a cooking style, molecular gastronomy is a scientifically oriented approach towards understanding the basic mechanisms occurring during cooking. This has been rising and has received significant publicity and media coverage during the last few years. It is described as the most exciting development within haute cuisine. New products, combinations, creative methods, techniques and tools are used in the process of producing the food (Mielby and Frøst, 2010, Vega and Ubbink, 2008).
Science-based cooking is closely associated with the design of stimulating and novel dishes that provide an explosion of sensations. The evolution and history of gastronomy has been clearly influenced by the social and economic backgrounds. In the past a diet was seen as a means of providing the adequate nutritional components, a concept that has evolved into a desire of maintaining or improving health through food. Likewise, the evolution of gastronomy into haute cuisine has led to the utilization of new ingredients and technologies that could interact with nutrients and alter the contribution of the dishes to the overall diet. The main goal of haute cuisine cooks is to innovate and design delicious dishes with new textures and flavors, which promote new sensations in customers (Navarro et al., 2012).
Forms of Molecular Gastronomy Include the following:
Gelification– Jelly using agar agar
Spiralising– Pasta using courgettes, garlic, oil and herbs Vaccum sealing– Carpaccio of beetroot with onion + pear Emulsification– Foam using soy lecithin
Siphon whipping– Espuma using xanthan gum + siphon whipper
Sous vide– Using vaccum sealer and water bath Spherification– Using sodium alginate and calcium lactate Misting– Using rose water
Smoking– Infuse dish with smoke of wood, herb, spice, flower
Carpaccio– Using mandolin and salt Vegetable porridge– Using blender Vegetable tartare– Using food processor Civiche – Using Knife or food processor
Food additives often used in Molecular Gastronomy: There are around 2500 chemicals that are added to foods for specific purposes such as preserving or processing and enhancing flavour or colour. These include colouring, stabilisers, acidifiers, preservatives, enzymes and texturing agents. For raw vegan molecular gastronomy purpose we only use a very small number of these which are plant based, natural extracts.
(Aa) Agar agar– is a natural gelling agents extracted from red algae, often used to create solid pearls, gel spaghettis and jellies. Agar agar does need high heat to activate. We use it in a tea based jelly.
(Sl) Soy lecithin– is a natural emulsifier extracted from soy beans, often used to shape watery solution into airs. We use to make fancy foams and espumas. It is also used in recipes where you need to combine fats/oils with water.
(Xg) Xanthan gum– is a natural thickener derived from glucose via fermentation. Ofen used to stabilize emulsions and thicken sauces and drinks.
(Cl) Calcium lactate– is a calcium salt used with sodium alginate in the process of spherification. Calcium lactate is produced by mixing lactic acid with calcium carbonate and can also be used as a calcium supplement,
as a firming agent, thickener, flavour enhancer and leavening agent.
(Sa) Sodium alginate– is a natural gelling agent extracted from brown algae and used with calcium lactate for spherification.
Gelification – Jelly
I like to make herbal jelly. Make herbal tea of choice, add 1 teaspoon of agar agar per 500 ml of water. Brew for 10 minutes at 80 degrees to activate agar agar, then strain into blender and blend with flavor of choice such as orange juice / spirulina / goji berry other fruits. Add nuts/seeds or seed or nut butter for a creamer jelly. Blend and pour into mould then set.
Fruit or vegetable can be made by marinating or pickling fruit or veg, then chopping very small and seasoning with lemon/lime juice + herbs like cilantro. A great example of this is using black grapes deseeded + diced small, add diced peppers + onions and season with lime juice + fresh herbs.
Another option is cauliflower ceviche, again it’s best to pickle or marinate first to break down cell wall + infuse flavour.
Beetroot works best for this. Slice as thin as possible using only a mandolin, a knife will not out thin enough. Marinate slices with oil, salt onion and fear overnight. Marinate in a lunchbox, jar or vaccum sealed bag. This will break down the cell wall of the beetroot and infuse with flowers of onion + apples.
To make the tartare, simply blend all marinated ingredients together just very slightly so not too smooth and wet. Use sprouts for base of tartare and add blended mixture on top using a chef ring and just dress the plate.
Foods can be heated, never above 118 F, using a piece of equipment called a dehydrator to simulate sundrying. They are enclosed containers with heating elements to warm at low temperatures. A fan inside the dehydrator blows the warm air across the food, which is spread out on trays. Dehydrators can be used to make raisins, sundried tomatoes, kale chips, crackers, breads, croutons, and fruit leathers.
You can pickle any fruit or vegetable through a process of lacto fermentation. Lacto-fermentation really is more art than science. The science part is simple: lactobacillus (from a prepared culture, fresh whey, or just naturally occurring) plus sugar (naturally present in vegetables and fruits), plus a little salt, minus oxygen (anaerobic process), plus time, equal lactic-acid fermentation. The length of fermentation can vary from a few hours to two months or more. The temperature of the room where fermentation occurs will determine the length of time. The ideal temperature is around 72°F, but warmer or cooler temperature will still work. (Some strains of bacteria require specific temperature ranges.) The length of time is dependent more on the flavor you prefer than anything else and since the flavor level of lacto-fermented vegetables increases with time you will want to sample often until you are experienced enough to know what works for your tastes. Just keep in mind that you don’t want to introduce a lot of oxygen to the fermentation process as this increases the chance of spoilage. Lacto-fermentation is generally done in an airtight container or a crock with a water seal that prevents air from contaminating the culture. The general rule is dissolving 20g of salt into 1 litre of water and cover vegetbales in an airtight jar for 3 weeks.
Spherification is the culinary process of shaping a liquid into spheres usually using sodium alginate and either calcium chlorate or calcium glucate lactate, which visually and texturally resemble cavair. There are two main methods for creating such spheres, which differ based on the calcium content of the liquid product to be spherified. For flavored liquids (such as fruit juices) containing no calcium, the liquid is thoroughly mixed with a small quantity of powdered sodium alginate, then dripped into a bowl filled with a cold solution of calcium chloride, or other soluble calcium salt.
Just as a teaspoonful of water dropped into a bowl of vegetable oil forms a little bubble of water in the oil, each drop of the alginated liquid tends to form into a small sphere in the calcium solution. Then, during a reaction time of a few seconds to a few minutes, the calcium solution causes the
outer layer of each alginated liquid sphere to form a thin, flexible skin. The resulting “popping boba” or artificial “caviar” balls are removed from the calcium-containing liquid bath, rinsed in a bowl of ordinary water, removed from the water and saved for later use in food or beverages.
Reverse spherification, for use with substances which contain calcium or have high acid/alcohol content, requires dripping the substance (containing calcium lactate or calcium lactate gluconate) into an alginate bath.
The spherification technique was introduced by el Bulli in 2003. It consists of a controlled jellification of a liquid, which forms spheres when submerged in a bath. The spheres can be made of different sizes and have been given names like caviar when they are small, eggs, gnocchi and ravioli when they have larger size. The resulting spheres have a thin membrane and are filled with the flavored liquid. A slight pressure of the mouth on the sphere makes it burst and release an amazing explosion of flavor. The spheres are flexible and can be carefully manipulated. It is possible to introduce solid elements in the sphere, which will remain in suspension in the liquid giving the possibility of introducing multiple flavors and textures in one preparation.
There are two main kinds of spherification techniques and each of them has its advantages and disadvantages which make them more suitable for certain recipes. The Basic Spherification technique consists of submerging a liquid with sodium alginate in a bath of calcium. The Reverse Spherification technique consists of submerging a liquid with calcium content in a bath of sodium alginate. When the liquid drops into the bath, a thin coat of gel forms around the droplet as the calcium reacts with the sodium alginate.
There are also a couple of other techniques to create spheres which consist of instant jelling by immersing the liquid in cold oil or liquid nitrogen, but these are made with a completely different process and the resulting spheres are solid and have no liquid inside. So these are usually not considered “spherification” techniques.
The Basic Spherification technique is ideal for obtaining spheres with a very, very thin membrane that is almost imperceptible in your mouth. It results in a sphere that easily explodes in your mouth as if there is no solid substance between your palate and the liquid. The main problem of this technique is that once the sphere is removed from the calcium bath, the process of jellification continues even after rinsing the sphere with water. This means that the spheres need to be served immediately or they would convert into a compact gel ball with no magical liquid inside. The other issue of this technique is that jellification does not occur if the liquid acidity is high (PH<3.6) but this can be corrected by adding sodium citrate to the liquid to reduce the acidity level before the spherification process. The Basic Spherification technique doesn’t work with ingredients that have high calcium content. Examples of Basic Spherification are “Spherical Mango Ravioli“, “Liquid Pea Ravioli”, and Caviar of carrot juice.
For direct spherification a 0.5% to 1% sodium alginate base is used with 0.5% to 1% calcium lactate setting bath. For Example100ml of carrot juice mixed with 0.5g to 1g of sodium alginate dropped into a bath of 1000ml of water mixed with 5g to 10g of calcium lactate.
The technique of Reverse Spherification is much more versatile than Basic Spherification as it can make spheres with almost any product. It is best for liquids with high calcium content or alcohol content. Contrary to the spheres made with the Basic Spherification process, these spheres have a thicker membrane and are long-lasting as the process of jellification can be stopped when the sphere is removed from the sodium alginate bath and rinsed with water. Thanks to these characteristics, the
Reverse Spherification spheres can be manipulated more easily and can be used in more ways (for example as fillings in sponge cakes or mousses, in cocktails or can even be macerated in aromatized olive oil for a few days). Examples of Reverse Spherification are “Yoghurt Spheres”, “Liquid Mozzarella Spheres” and “Spherical Olives“.
For the flavored base a ratio of 1.0% to 3.0% calcium lactate is typically used with a setting bath of
0.4 to 0.5% sodium alginate. For Example100ml of an acidic liquid or liquid high in calcium is blended with 1g to 3g of calcium lactate and formed into spheres then added to a bath of 1000ml of water mixed with 4g to 5g of sodium alginate.
Sodium Alginate is a natural polysaccharide product extracted from brown seaweed that grows in cold-water regions. In presence of calcium, sodium alginate forms a gel without the need of heat.
In Basic Spherification, the gelling occurs thanks to the diffusion method in which the crosslinking calcium ion diffuses from an outer reservoir into an alginate solution. Gels form when a calcium salt is added to a solution of sodium alginate in water. The gel forms by chemical reaction, the calcium displaces the sodium from the alginate, holds the long alginate molecules together and a gel is the result. No heat is required and the gels do not melt when heated. The gel coating is formed inside the droplet. Because the calcium ions continue diffusing towards the center of the droplet even after removing the sphere from the calcium bath, the gelification process continues and will eventually form a solid gel sphere.
In Reverse Spherification, the calcium ions diffuse from the droplet into the alginate bath, forming a gel coat outside the droplet of flavored liquid. Because the calcium ions are diffusing from the inside out and no alginate molecules are getting into the droplet, the gelification process stops as soon as the spheres are removed from the alginate bath. This allows you to store the spheres for later use.
There are a few ingredients necessary for Basic Spherification and Reverse Spherification but there are only two that are essential and absolutely required to start the spherification process: sodium alginate and some calcium element.
Sodium Alginate: a natural product extracted from brown seaweed that grows in cold water regions. It is soluble in cold and hot water with strong agitation and can thicken and bind. In presence of calcium it forms a gel without the need of heat. Sodium Alginate is used in the food industry to increase viscosity and as an emulsifier. It is also used in indigestion tablets. It has no discernable flavor.
Calcium Chloride: used to make the calcium bath for Basic Spherification. This is probably the cheapest of all ingredients and it is used mostly with Basic Spherification because its saltiness does not affect the main ingredient taste as it is only used for the bath. Calcium chloride is a calcium salt traditionally used in the food industry to make cheese and it is also used in many other applications as pickling agent, firming agent, flavor enhancer, stabilizer, etc. It is very soluble in water and it must be kept in tightly sealed containers.
Calcium Lactate: used to increase the calcium content of the main ingredient in Reverse Spherification. Calcium lactate is a black or white crystalline salt made by the action of lactic acid on calcium carbonate. It provides a less bitter taste than calcium chloride when added to the main ingredient. It will dissolve in fat. It is traditionally used in foods as a baking powder and to make aged cheeses. It is often added to sugar-free foods to prevent tooth decay and to fresh cut fruit to keep it firm and extend shelf life.
Calcium Lactate Gluconate: Calcium lactate gluconate, also known as GLOCAL, is a soluble salt of calcium, lactic acid and gluconic acid used in effervescent calcium tablets. Its chemical formula is Ca5 (C3H5O3)6·(C6H11O7)4·2H2O. It was first developed by Sandoz, Switzerland. Calcium lactate gluconate is used in the functional and fortified food industry due to its good solubility and neutral taste. In addition, it is used in various spherification techniques in molecular gastronomy. It can also be used to help neutralize HF (hydrofluoric acid) poisoning.it is ideal to increase the calcium content of the main ingredient in Reverse Spherification. The main ingredient consistency and flavor is not altered by the addition of calcium lactate gluconate as it has no discernable flavor and dissolves in cold liquid without altering its density. It is versatile as it can be used in liquids with high acid, alcohol or fat contents. To avoid difficulties in dissolving, add calcium lactate gluconate before any other powder product.
Sodium Citrate: can be used to reduce the acidity of the main ingredient when doing Basic Spherification. The Basic Spherification process does not work if the main ingredient is too acidic (PH<3.6). Sodium citrate has a sour taste as well as having a salty taste so use with moderation when adding to the main ingredient not to alter its taste too much. Sodium citrate is usually used in the food industry as an additive for flavor and as a preservative. It is used in club soda and most lemon-lime soft drinks for their sour and salty flavors.
Xanthan: used to thicken the main ingredient in Reverse Spherification. When the main ingredient density is too liquid to form spheres in the alginate bath, a thickener like Xanthan is used. It is obtained from the fermentation of cornstarch with Xanthomonas campestris bacteria (found in cabbage). It is gluten free and can be used as a substitute for gluten in baking (used along with non-gluten containing flours). Soluble in hot or cold water, stable over a range of pH and temperatures, can thicken items with a high alcohol content, compatible with and stable in systems containing high concentrations of salt.
Scale with 0.1g precision: most of the recipes require very low amounts of “molecular” ingredients, usually fractions of a gram. To be successful with spherification it is important to be precise and use a scale with such precision. Scales with a large weighing range and this precision could be really expensive but scales that can only weigh up to 200g or 500g are much more affordable. You can then have another 1g precision scale for weighing heavier items. This is probably the most essential piece of equipment you need even though there are charts out there to convert the molecular gastronomy chemicals’ weight to volume so you can use a measuring spoon instead but this is not very precise. The density of the ingredient is very sensitive to packing of the powders and it can also vary by brand.
Dosing spoons: used to pour the main ingredient into the bath to form the sphere. A set of measuring spoons with spherical shape is recommended since they conveniently come in different sizes to create ravioli, gnocchi, etc.
Collecting spoon: used to remove the spheres from the bath. A small slotted spoon will do the job perfectly. It is better if they are metallic so the sphere can slide easily from the spoon on to the plate. Some plastic spoons have a rough surface that prevents the sphere from sliding off the spoon
Syringe: used for creating caviar. Just a regular syringe without the needle is needed. If you need to produce caviar in high quantities consider getting a Caviar Maker.
PH Indicator Paper: used for measuring the acidity (PH) level of the main ingredient when doing Basic Spherification since it doesn’t work if the PH level is below 3.6.
Flat pan for the bath: ideal for Reverse Spherification because the spheres tend to stick together if they become in contact with each other. If you use a bowl, it will be harder to keep the spheres separate, as they will all flow into the middle of it as you pour the main ingredient into the bath to create multiple spheres.
Immersion blender: used to dissolve the sodium alginate, which only dissolves with strong agitation. It is also used in several recipes to prepare the main ingredient and mix the xanthan gum.
Fine Skimmer: used to collect caviar spheres from the bath and rinse them under running water to remove the extra calcium on the surface. Use a skimmer with small holes so the caviar spheres can’t go through. You can use the collecting spoon but a larger fine skimmer will be faster.
Fine Sieve and Cheesecloth: several recipes require passing the main ingredient through a fine sieve and sometimes through a sieve lined with cheesecloth to obtain a smooth liquid with ultra small solid particles. This is an inexpensive alternative to using a superbag, a porous bag that works as an extraordinarily fine filter that won’t impart a metallic taste to delicate ingredients, plus is flexible yet durable, heat resistant and dishwasher safe. If you can afford a superbag, I recommend it. You’ll get better results.
Appetizer spoons: some of the spheres are very delicate to be handled by hand or with spoons by the diners so you’ll have to carefully place them on appetizer spoons to be served. This is particularly necessary with basic spherification spheres due to their more delicate membrane.
Gelification is the process of turning a liquid into a gel. This process can result in various textures ranging from a soft and elastic gel to a hard and brittle one. Agar-agar is often used to deconstruct liquids into pearls, sheets and spaghetti. Agar-agar needs to be brought to a boil to be activated and gelification will occur when the mixture is cooled down.
In molecular gastronomy, emulsification is defined as the process of turning liquids into light foams that will liberate and intensify flavors. A property of soy lecithin is used to allow air bubbles to remain trapped into many liquids.
To efficiently incorporate air into a lecithin-based solution, the use of a hand blender is preferred as some eggbeaters are not powerful enough. To maximize results, slightly tilt the blender to allow the blades to almost reach the surface of the liquid and avoid completely immersing the head of the blender. The use of a flat-bottomed square bowl is suggested, as it will help avoid the formation of whirlpools, which would slow down the creation of the foam. The soy lecithin-based solution can be re-blended several times to obtain more foam.
There is much more one can do with a culinary whipper than make whipped cream! For instance, xanthan gum can be used to replace the binding effect, which is usually provided by the fat of cream to create an incredibly tasty low-fat whipped cream. Further, agar-agar allows the creation of warm mousses that can be served as appetizers or side dishes and cold soluble gelatin adds an exquisite melt-in-the-mouth effect to desserts!
Never load more than one cartridge into the culinary whipper at a time. Before loading a cartridge, make sure that the lid is tightly sealed. The trigger is very sensitive. To avoid creating a mess, slowly press the trigger over the sink to let out a bit of air pressure.
This involves massaging your vegetables with oil and salt in order to soft and withdraw the moisture to make it more digestible, this can also be called dry pickling and many other flavors and spics can be introduced during the marinating stage, the vegetable will absorb all the marinating flavors and will transform the vegetable.