[@hubermanlab] The Chemistry of Food & Taste | Dr. Harold McGee

Link: https://youtu.be/zqANjUGarAw

Short Summary

Number One Takeaway:

Slow down your eating and pay attention to the flavors and textures of food, as the tasting experience is dynamic and evolves over time due to chemistry occurring in the mouth.

Executive Summary:

Dr. Harold McGee explains the chemistry of food and cooking, emphasizing the importance of heat, salt, and other elements in transforming flavors. He highlights the value of slowing down and savoring food to fully appreciate the complex chemical reactions and sensory experiences that unfold in the mouth. Ultimately, this discussion reinforces how understanding food chemistry can lead to a richer, more enjoyable eating experience.

Key Quotes

Here are 5 direct quotes from the transcript that represent particularly valuable insights:

1. "Test everything."

   • This highlights the importance of experimentation, even when established "facts" are presented.

2. "I think a lot of what we face nowadays in the the sphere of health and nutrition is about that conflict. you know, there there are papers identifying mechanisms, but then they don't play out in clinical trials, which is the, you know, and then there are people in the real world who are doing things for which there's really no peer-reviewed research, but you get the sense that maybe they're on to something, you know."

   • This acknowledges the tension between scientific theory and practical application in nutrition and health.

3. "So to me what that says is there is no the answer for this kind of question and that it really does depend on individual physiology and what what people can tolerate um for their own particular reasons. I don't think there are any um principles by which you can choose to uh combine or not combine foods um that would make a difference to your health. Also, it's um you know, we're eating so many different things so many times a day that uh it I think would be really hard to kind of tease out any particular relationships like this. And even if they do exist, they probably exist only for subpopuls and not for the world at large."

   • This emphasizes the individuality of dietary needs and the limitations of blanket recommendations.

4. "The longer you extract, the more you extract, the larger the molecules you're able to remove. And those larger molecules are the ones that tend to be tanic and aringent and really bitter."

   • This provides a specific chemical explanation for the impact of brewing time on the flavor of coffee.

5. "I think what's going on is that kids have a heightened sense of taste and smell."

   • This offers a possible explanation for children's often strong aversions to specific foods.

Detailed Summary

Here is a detailed summary of the YouTube video transcript provided, focusing on the key topics, arguments, and information discussed, while excluding advertisements:

• Introduction:

  • Dr. Andrew Huberman introduces the podcast and guest, Dr. Harold McGee, an expert on the science and chemistry of food and cooking.
  • Huberman emphasizes McGee's ability to explain why foods taste the way they do and how to improve their taste.
  • The discussion covers topics such as cookware's impact on taste, salt's effect on bitterness (including in coffee), meat preparation for umami, polyphenols in chocolate, and the debate on expensive vs. inexpensive wines.

• Cookware & Taste (Copper Bowls):

  • McGee recounts his experience of initially dismissing the idea of using copper bowls for whipping egg whites until historical evidence and personal experimentation proved its significant impact on color, texture, and taste.
  • He reveals that copper is also used in jam making to inhibit the breakdown of sucrose, a technique known and used by French cooks for generations.
  • McGee underscores the lesson that practical experience can often trump initial scientific assumptions.

• Evolution of Cooking Methods:

  • McGee discusses how ancient cooks, through experimentation, arrived at effective cooking techniques, often without a full understanding of the underlying chemistry.
  • He contrasts this with instances where scientists made incorrect suggestions about cooking based on incomplete knowledge.

• Heat and Food Chemistry:

  • Heat fundamentally rearranges the molecules within food, often breaking them down into smaller, more detectable components.
  • Proteins, carbohydrates, and fats (macromolecules) are broken down into smaller molecules, which stimulate taste and smell receptors.
  • Heated food molecules react with each other and oxygen, generating a variety of volatile aroma molecules and tastable molecules.

• Umami (Savoriness):

  • McGee explains umami's history, including its initial skepticism in the West, until the discovery of glutamate receptors.
  • He describes umami as a feeling of "fullness and length" in flavor.
  • Huberman notes how the taste of umami seems to extend beyond just the mouth, possibly linked to reward pathways evolved due to the historical scarcity of protein.
  • McGee highlights how little we know about the mechanics of taste signaling in the body.

• Maillard Reaction:

  • The color change that occurs with the browning of meat is indicative of Maillard reactions, reactions between fragments of proteins and carbohydrates.
  • These reactions are complex and generate sugars and a wide variety of other taste-active molecules.

• Taste Conjugates:

  • Conjugate molecules exist within many foods, the breaking apart of which releases different flavours to the mouth.
  • Enzymes in the mouth can break apart conjugate molecules releasing aromatics.
  • Eating more slowly allows for these changes and nuances to be appreciated.

• Food Order and Palate Cleansers:

  • McGee discusses the French tradition of soup first, then appetizer, then entree, and salad last.
  • Soup early helps fill the stomach, while the salad refreshes after the heavy main course.
  • Palate cleansers (cold and slightly tart) can help break up rich courses, but are partly for show.

• Taste Thresholds and Adaptation:

  • Taste preferences are malleable, as evidenced by studies on reducing sodium content in packaged goods.
  • Over time, individuals can adjust their thresholds and preferences for basic tastes.

• Unprocessed Foods and Taste:

  • McGee suggests that consuming foods closer to their natural state (strawberries, blueberries, etc.) provides a richer taste experience compared to combining many flavors in processed foods.
  • He argues that processed foods prioritize stimulation over appreciation, masking the individual components of the natural ingredients.

• Coffee Chemistry:

  • Grind size is important, and coffee brewing extracts around 20% of the original coffee weight, which is mostly the "good stuff."
  • Extended brewing extracts larger molecules, which tend to be more tannic and bitter.
  • Water temperature is critical, and preferences vary, highlighting the importance of experimentation.

• Tea Chemistry:

  • The tannic experience in tea depends on how the tea leaf has been treated.
  • McGee describes making his own teas at home, using a variety of drying methods.
  • Herbal teas are fine at the end of a meal, and tea can contain polyphenols, but the health effects are unclear.

• Polyphenols:

  • Polyphenols are reactive and can cross-link proteins.
  • There were historic diet trends about avoiding the combination of proteins and carbohydrates, but now scientists think individual physiology matters more.

• Onions & Garlic:

  • Onions use sulfur molecules to defend against animals. Cutting the onion is a chemical warfare.
  • Crying is caused by volatile molecules irritating the eyes, which can be mitigated by wearing goggles or rinsing.
  • The histamines caused by ingesting onions can also lead to gut pain.

• Spice:

  • Capsaicin in peppers is designed to be aversive to animals.

• Taste Receptors:

  • There are genetic differences among people in terms of density of umami receptors and sweet receptors.

• Supertasters:

  • Supertasters were found by scientists counting taste buds.
  • These individuals have a higher density of taste buds and are especially sensitive to bitterness and acidity.
  • However, being a "supertaster" isn't necessarily beneficial for a chef, as they might dial down flavors too much for the average consumer.

• Salting Fruit:

  • Salting fruit can diminish bitterness.

• Alcohol Fermentation:

  • Alcohol has been consumed since before we were homo sapiens.

• Wine:

  • Expectations influence perception, and consumers can get fooled by food coloring.

• Cheese:

  • Fermentation by microbes breaks down proteins and fats, generating small molecules that are responsible for giving it flavor.
  • Parmesan cheeses' crystals are often tyrrosine or other amino acid derivatives.
  • Smoke on cheese is a ward against bugs that are after the nutrients.

• Fermentation Practices:

  • Fermentation began with observation.
  • Today there are now newer versions using different foods because of the blending of human culture and exchange of techniques.

• McGee's background:

  • Originally in astronomy at Caltech, then shifted to literature. A question with dinner conversations about why beans give you gas caused him to dive into the science of food.

• Bean flatulence:

  • Oligosaccharides cannot be broken down so microbes make CO2 and H gas. Solution is soaking in water or boiling after soaking.

• Fermented food eating:

  • Eats Kimchi.

• Kids and picky food:

  • Kids might have heightened tastes and sensitivities to certain foods when they are developing.
  • Kids might feel conservative about what they will eat, or be averse to certain foods.

• Cilantro:

  • Has molecules that also appear in soap.

• Keats:

  • Keats' life as a medical student and experience with death greatly influenced his poetry.
  • McGee recommends reading Keats's "To Autumn."