Overview:
Nathan Mirbaud is a renowned figure in gastronomy, known for his groundbreaking work in creating knowledge, publishing, and developing materials to enhance the understanding of gastronomy. His work spans across modernist cuisine, modernist bread, and effective communication to create new knowledge in the field.

Nathan Mirbaud’s Contributions:
Nathan Mirbaud has revolutionized the culinary world with his innovative book, “Modernist Cuisine,” which has significantly advanced the boundaries of culinary science. His expertise extends beyond being a chef, as he is also a scientist, photographer, and technology officer at Microsoft, demonstrating his diverse range of skills and knowledge. Mirbaud holds an impressive academic background, including a PhD in mathematics, theoretical and mathematical physics, two master’s degrees, and a culinary diploma, reflecting his dedication to academic excellence.

Physical Chemistry in Gastronomy:
Mirbaud’s work delves into the field of physical chemistry, specifically focusing on emulsions, gels, and foamings, which play a crucial role in culinary techniques and the creation of various dishes. These topics hold immense interest from a culinary perspective, as they provide a scientific understanding of the interactions between ingredients and the resulting textures and flavors in dishes.

Interactive Q&A Session:
The discussion will involve addressing questions posed by students, providing an interactive and engaging format for exploring the intricacies of physical chemistry in gastronomy. Mirbaud’s insights and expertise will shed light on these questions, offering valuable knowledge and fostering a deeper understanding of the scientific principles underlying culinary techniques.

Foams:
To make a foam, one needs to add something to give it body and allow foaming to occur. Soda, beer, and whipped cream all have foaming agents. Alcohol destabilizes foams because it drains out of the foam. Temperature affects foam stability. As temperature rises, the chemical basis for holding the bubbles together weakens, and evaporation occurs. Cappuccino and coffee lattes have heat-stable foams due to scalded proteins.

Emulsions:
Low-fat mayonnaise is difficult to make because oil is a major component (80-90%) and substituting it with something else significantly changes the product. Gels can be used to create low-fat mayonnaise, but it will always be a compromise in terms of flavor and texture. Vinaigrette or other sauces may be a better option when making a dish with a low-fat mayonnaise substitute.

Thickeners:
Thickeners can be used to stabilize emulsions and foams. Xanthan gum can be used to thicken lychee and lime soda, creating a foam that looks like an Alka-Seltzer tablet. Gum Arabic is commonly used in sodas to increase body and hold bubbles without creating a thick, dense foam.

Emulsifiers vs. Thickeners:
Emulsifiers and thickeners are both used to stabilize emulsions, but they achieve this through different mechanisms. Thickeners slow down the movement of particles in an emulsion, stabilizing it over time. Emulsifiers use molecules with dual affinities to sit at the interface between oil and water, preventing the emulsion from separating.

The Role of Fat Crystals:
In whipped cream, fat crystals from butterfat act as stabilizers for the foam structure. This is an example of how different substances can be used to achieve similar results in creating stable emulsions or foams.

Stability and Ingredient Choice:
The choice of emulsifier or thickener is not a one-size-fits-all solution. For minor changes or short-term stability, the specific choice may not matter significantly. For long-term stability or specific applications, selecting the right ingredient is crucial.

Case Study: Modernist Beurre Blanc:
Nathan Myhrvold sought to create a beurre blanc that was easier to make and more stable than traditional recipes. A specific hydrocolloid called BVA was found to be essential for achieving the desired stability in this particular application.

Thickener Selection for Gels at Low and High Temperatures:
Consider the properties of various gels to determine the most suitable thickener. Gelin is Nathan Myhrvold’s favorite high-temperature gel due to its desirable properties. Agar can also be used at higher temperatures, and both Gelin and Agar can be adjusted to achieve different gel strengths. Gelin offers more control over gel texture, allowing for a range from soft to fragile and chunk-breaking consistency. Agar is another viable option, and numerous other thickeners are available, each with its own characteristics.

Factors Influencing Thickener Choice:
The vast array of thickeners available can make choosing the right one challenging. The selection process often involves experimentation to find the thickener that best suits the desired gel properties.

Ingredients for Gels:
Gelling agents like gellin and alginate require divalent cations (ions with a +2 charge) to form gels. Agar and gelatin do not require ions to gel.

Selective Gelation:
Spherification uses the availability of ions to selectively solidify a gel, creating a shell while the inside remains liquid.

Gellin for Emulsions and Foams:
Gellin is a shear-thinning substance that becomes thinner under shear force. This property makes it ideal for stabilizing emulsions and creating foams.

Gas Composition and Foam Stability:
The gas used in cooking is usually air or a component of air, such as CO2. CO2 is soluble in water and dissolves into it under pressure, creating bubbles when the pressure is released. Nitrogen is less soluble in water, but can also be dissolved under high pressure, creating a smooth and long-lasting foam.

Nitrous Oxide in Whipped Cream:
Nitrous oxide is extremely soluble in fat, making it ideal for creating whipped cream. When nitrous oxide is dissolved in the fat globules of cream, it expands and stabilizes bubbles, resulting in whipped cream.

Avocado Foam:
Avocado can be diced and whipped in an ISI siphon to create a foamy texture. A thin guacamole sauce can also be whipped to create a crepe-like texture.

Role of Fat in Air Bubble Stabilization:
Fat plays a crucial role in stabilizing air bubbles in whipped cream and ice cream. Fat molecules surround and coat the air bubbles, preventing them from coalescing and collapsing.

Whipped Cream:
Whipped cream forms when the fat crystals in the cream stabilize the air bubbles as it gets cold. The fat crystals act like a foaming agent or emulsifier, helping to maintain the whipped cream’s structure. Artificial whipped cream often uses saturated fats to achieve a crystalline texture at room temperature.

Ice Cream:
Ice cream is a foam with a high overrun, meaning it contains a significant amount of air compared to the actual product. The whipping and incorporation of air in ice cream occur as the mixture gets cold. The fat in the ice cream crystallizes during the freezing process, helping to stabilize the air bubbles and maintain the ice cream’s structure.

Comparison:
Whipped cream and ice cream both rely on fat crystallization to stabilize the air bubbles and maintain their structure. However, ice cream is made while freezing the mixture, while whipped cream is made at room temperature. Artificial whipped cream often uses saturated fats to achieve a crystalline texture at room temperature, while ice cream typically uses a combination of fats.

Replacing Saturated Fats in Whipped Cream:
Replacing saturated fats in whipped cream is challenging due to the emulsion of milk fat and water stabilized by milk proteins. Scientists have conducted research to find alternatives, but it remains a complex task to achieve the desired texture and stability without saturated fats.

Emulsions in Cooking:
Emulsions are natural or artificial mixtures of two immiscible liquids. In cooking, emulsions are often used to create foams, such as whipped cream or meringue. Saturated fats, like those found in cow’s milk, can be whipped into stable foams because they crystallize. Unsaturated fats, like those found in pistachio oil, cannot be whipped into stable foams because they do not crystallize.

Hydrocolloids in Cooking:
Hydrocolloids are substances that can stabilize emulsions and foams. Gelatin is a hydrocolloid that can be used to stabilize hot whipped cream. Cocoa butter is a flavorless fat that can be used to make artificial cream that can be whipped like whipped cream.

Importance of Applied Energy in Emulsions:
The amount of energy applied to an emulsion is important because it determines the size of the bubbles in the emulsion. Smaller bubbles create a more stable emulsion. Larger bubbles create a less stable emulsion.

Emulsion Bubbles:
Emulsions contain bubbles of one substance inside another, such as oil in water or water in oil. The surface tension of these bubbles depends on their curvature, with smaller bubbles requiring more energy to form. Small emulsion bubbles create a silky, smooth texture and prolong the emulsion’s stability. However, creating smaller bubbles also generates heat, which can destabilize the emulsion.

Nucleation Points for Bubbles:
Nucleation points are necessary for bubble formation in liquids. In the absence of nucleation points, bubbles cannot form spontaneously due to the high energy required for infinitely small bubbles. Champagne flutes often contain a small flaw in the glass to serve as a nucleation point for bubbles.

Thickeners in Fat:
Fat is a nonpolar molecule that doesn’t readily dissolve substances. Polar molecules, like water, can rip molecules apart into ions. Modified starches, such as nzorbit, can be used to thicken oil. Nzorbit is a tapioca malodextrin starch that combines with oil to form a solid or thicken it in different quantities.

Olive Oil Margarine:
Olive oil margarine can be made using emulsifiers and thickening gels in the aqueous phase. Achieving a consistency similar to butter is challenging due to the lower fat content in olive oil compared to butter. Aioli, a flavored spread made with olive oil, can achieve a consistency similar to soft butter.

Ingredients for Making Bubbles in Foams:
This question is not answered in the provided text.

Ingredients for Bubble Toys:
Soap or Detergent: Acts as an emulsifier, helping to remove oil from clothes and encapsulate it in emulsions. Polysorbate (Tween): A powerful emulsifier that can be used to make bubbles. Lecithin: A natural emulsifier that can also be used to make bubbles. Glycerol or Sugar Syrup: These thickeners help create larger bubbles.

Techniques for Making Bubbles:
Aquarium Pump: Place an aquarium pump in the liquid to create a stream of air bubbles. Avoid Blowing Bubbles Directly: Blowing bubbles directly can be unsanitary. Instead, use an aquarium pump or other device to create the bubbles.

Importance of Physical Chemistry in Cooking:
Physical chemistry plays a crucial role in culinary innovation, as it provides a scientific understanding of the processes involved in cooking. Understanding physical chemistry allows chefs to deviate from recipes and create novel dishes by manipulating ingredients and techniques.

Comparison to Architecture:
Nathan Myhrvold compares culinary innovation to architectural design. Just as architects rely on engineering principles to design complex structures, chefs can use physical chemistry to create innovative dishes that push the boundaries of cuisine.

Benefits of Scientific Knowledge for Chefs:
Understanding physical chemistry empowers chefs to appreciate and enjoy food more deeply. Chefs who possess scientific knowledge can create unique and surprising dishes, enhancing the dining experience.

Influence of Science on Modern Cuisine:
The integration of science in modern cuisine has led to significant advancements and creativity in the culinary world. Chefs like Ferran Adria and Juan Maria Arzak have drawn inspiration from scientific knowledge to revolutionize culinary techniques and create innovative dishes.

Importance of Accessibility to Scientific Knowledge:
Nathan Myhrvold emphasizes the need for chefs to have access to scientific knowledge to drive innovation and creativity. His book, Modernist Cuisine, was written to make scientific knowledge accessible to chefs and promote its application in culinary arts.

The Scientific Method in the Kitchen:
The scientific method, the foundation of rational thought, can be applied in the kitchen to investigate and understand culinary processes. While cooking is considered an art, applying the scientific method allows chefs to systematically explore and refine their techniques, leading to consistent and successful results.

Art and Science in Cooking:
Cooking can be art when it engages our thoughts and emotions as much as other artistic forms. Architecture is an example of an art enabled by science, and cooking shares this characteristic.

Empirical Learning in the Kitchen:
Cooking has been practiced for a long time, often before the scientific principles behind it were fully understood. Examples like wine and bread making illustrate how empirical knowledge has helped us develop culinary techniques. Traditional chef training does not always incorporate the latest scientific advancements.

Personal Preferences in Food:
Myhrvold emphasizes that food choices are personal and should not be dictated by others. He respects those who prefer traditional cooking methods and ingredients, even if he believes there is room for innovation.

Cultural Evolution of Culinary Tastes:
Myhrvold challenges the idea that our grandparents were the ultimate culinary authorities. He points out that food preferences and tastes evolve over generations. Sushi, once exclusive to Japanese cuisine, is now a part of global culinary heritage.

Challenges in Physical Chemistry and Gastronomy:
Physical chemistry research in gastronomy has been limited due to lack of funding. Government and industry funding has focused on basic food science and specific industry needs, such as preserving tuna for sushi. Chefs need to be more proactive in engaging with physical chemists and food scientists to address their specific challenges.

Thank You and Appreciation:
Juan Carlos Arboleda expresses gratitude to Nathan for his time and the informative answers provided during the one-hour interview.

Limited Time for Questions:
Arboleda acknowledges that they have many questions but recognizes that the one-hour time frame has been reached.

Conclusion of the Interview:
The interview between Juan Carlos Arboleda and Nathan concludes with mutual expressions of appreciation.