

The Science of Coffee
James Harper
The Science of Coffee is a journey into coffee’s hidden microscopic secrets to help you make even better coffee at home.
Documentary maker and coffee professional James Harper travels the world and speaks with leading coffee scientists to help you appreciate coffee more deeply.
You are going to get taken into the science of water, coffee extraction, plant genetics, espresso technology, latte foam, sonic seasoning, our sense of taste and smell, organic farming, roasting, grinding and freshness, and how to think like a scientist.
Press the Subscribe button so you don’t miss future episodes!
The Science of Coffee is a spin-off series from James Harper’s documentary podcast Filter Stories.
Follow James on Instagram: https://bit.ly/2Mlkk0O
Listen to Filter Stories: https://bit.ly/3ajoT5
Documentary maker and coffee professional James Harper travels the world and speaks with leading coffee scientists to help you appreciate coffee more deeply.
You are going to get taken into the science of water, coffee extraction, plant genetics, espresso technology, latte foam, sonic seasoning, our sense of taste and smell, organic farming, roasting, grinding and freshness, and how to think like a scientist.
Press the Subscribe button so you don’t miss future episodes!
The Science of Coffee is a spin-off series from James Harper’s documentary podcast Filter Stories.
Follow James on Instagram: https://bit.ly/2Mlkk0O
Listen to Filter Stories: https://bit.ly/3ajoT5
Episodes
Mentioned books

9 snips
Jul 28, 2025 • 26min
How specialty coffee woke up to water’s role in flavour
Discover how the coffee world finally recognized the vital role of water in shaping flavor. Dive into the pioneering work of Christopher Hendon and British roaster Maxwell Colonna-Dashwood, who transformed our understanding of water chemistry. Learn about Total Dissolved Solids and the significance of minerals like calcium and magnesium in perfecting your brew. Listen as experts share their evolving perspectives and practical insights that could revolutionize your coffee experience.

10 snips
Jul 28, 2025 • 39min
The two ingredients in water that ruin your coffee, and the ancient story behind them
Explore the surprising impact of water quality on your coffee's flavor. Discover how two key ingredients—calcium and hydrogen carbonate—can make or break your brew. Journey back 550 million years to a time when Earth was a lush paradise, and learn about the cosmic origins of today’s water. Uncover the challenges posed by modern tap water and how ancient life forms shape our current water sources. This episode reveals the intricate connection between water chemistry and the coffee experience, making each cup a tale of evolution.

13 snips
Jul 14, 2025 • 43min
Getting great water for coffee, step-by-step. Part 2: How to measure and treat your water
Lucia Solis, a coffee podcaster and former winemaker, joins the conversation to dive deep into how water quality can enhance your coffee experience. They tackle essential concepts like hardness and alkalinity, explaining why these factors matter for flavor and equipment life. Listeners learn practical ways to test their water at home and improve it, whether through filtration or mineral addition. The dynamic discussion not only demystifies water science but also ensures you can brew that perfect cup every time.

8 snips
Jul 14, 2025 • 26min
Getting great water for coffee, step-by-step. Part 1: Alkalinity, hardness and why it matters
Lucia Solis, a coffee professional and host of the Making Coffee podcast, joins the discussion about the crucial role of water quality in brewing. They delve into the concepts of alkalinity and hardness, explaining how these factors can dramatically alter coffee flavor. Listeners learn how to test their water at home and practical methods for achieving optimal water characteristics. A fascinating tasting experiment highlights the stark flavor differences between various water types, empowering coffee enthusiasts to improve their brewing experience.

Jun 23, 2025 • 54min
Farm to port: why specialty costs more
Delve into the fascinating journey of specialty coffee, tracing its path from Colombia's Finca El Chafarote to your cup. Discover the dedication and challenges of coffee production, including the intricate processes that elevate flavors while navigating transportation hurdles. Learn why specialty coffee costs 50% more than commodity coffee, revealing the artistry and care behind every brew. Explore essential quality control measures and the critical role of water quality in enhancing your coffee experience.

Jun 9, 2025 • 47min
Why one Colombian farmer chose specialty, and the other walked away
Travel to Colombia’s Huila region to explore why some farmers embrace specialty coffee while others walk away. Discover the contrasting choices of two producers, driven by hidden barriers and personal circumstances. Delve into the economic and environmental factors influencing their paths, revealing surprising truths about the coffee industry. This fascinating discussion uncovers what can be done to encourage more farmers to grow specialty coffee and highlights the complexity behind their decisions.

May 19, 2025 • 39min
The hard business of selling beautiful coffee, part 2
Discover the inspiring journey of a Brazilian coffee farmer as he transitions from mining consultancy to specialty coffee production. Learn about the challenges faced in securing fair prices and the innovative strategies employed by him and his daughter to connect with buyers. The emotional dynamics of family support and the personal losses they endure highlight the human aspect behind every cup. Explore the complexities of establishing a reputation in the American market and the impact of direct trade in shaping their specialty coffee future.

May 19, 2025 • 29min
The hard business of selling beautiful coffee, part 1
Discover the fascinating world of specialty coffee farming in Brazil, where tradition meets innovation. Hear the story of a former mining consultant battling the challenges of the coffee market at Fazenda Paraíso. Explore the transformative journey from bulk sales to crafting unique flavors. Learn about the struggles of farmers like Vicente, who aim for fair compensation while navigating market fluctuations. This is a deep dive into the personal stories and hidden realities behind the coffee beans we cherish.

35 snips
Mar 24, 2025 • 52min
The Speed of Heat: How to roast more coffee, faster!
Discover the fascinating world of coffee roasting as technology takes center stage. Explore the revolutionary heat transfer methods allowing for lightning-fast roasting that rivals traditional techniques. Delve into the experience of testing an industrial tangential roaster and witness the colossal whale-sized machine breaking records. With a blend of innovation and flavor experimentation, the podcast highlights why not everyone is roasting at breakneck speeds despite the available technology.

Mar 10, 2025 • 48min
Coffee Roasting: How baby plant food transforms into delicious coffee flavours
Delve into the fascinating transformation of coffee from seed to your cup. Discover the intricate role of amino acids and sugars in shaping flavors. Witness the Maillard reaction, where heat sparks a chain reaction turning nutrients into delightful aromas. Enjoy a vibrant discussion on the science behind coffee roasting and its community impact. Plus, get a sneak peek into future topics, including coffee supply chains and cold brew techniques!