Behind the Glass

Gus Zhu is the first Chinese national to become a Master of Wine. He works as a research and development scientist at Harv 81 Group, specialising in chemical analysis and sensory studies of aroma compounds in wine, cork, and oak. Gus holds a Master of Science degree in Viticulture and Enology from UC Davis, earned in 2017, and achieved his MW qualification in 2019. In addition to his research in flavour chemistry and sensory science, Gus is a professional wine educator, offering tutorials to wine enthusiasts around the world.

"The science of sensory perception is surprisingly complex and little understood, given that we all use our capacity to see, taste and smell many hundreds of times each day. Gus Zhu MW has written a fascinating – and easy to follow – guide to the way in which chemistry, biology, physics, genetics and winemaking interact to not only create the great diversity seen in today’s world of wine, but also shape our ability to taste, understand and appreciate these wines." - Natasha Hughes MW, wine and food writer

• Introduction: a welcome drink 1Part One: Sight 71. Why is red wine red? 11The chemicals that make wines red or pink, and other properties of colour2. The complex colour of white wines 26What makes a wine white? How do colour blindness and differences in colour perception affect our initial thoughts about a wine?3. Solids, tears and bubbles 40The other visual attributes of wine and how preconceptions affect our appreciation of winePart Two: Palate 574. Sweet sensation and yummy umami 62Debunking the tongue map, explaining taste buds and exploring the first two basic tastes: sweet and umami5. Sour grapes and mysterious saltiness 76The science behind the more acquired tastes of sour and salty and an exploration of taste interactions, including food and wine pairing6. Some bitter truths about taste 92The bitter taste, fat as the potential sixth taste, and the genetic diversity of human taste buds7. Tactile sensations and acquired taste 102The sensations derived from touch–position and pain– temperature. Does our palate change as we grow up?Part Three: Smell 1138. A bouquet of flowers and a fruit bowl 118Revealing the two ways of smelling and introducing the floral and fruity aromas in wine9. Sniffing out the green aromas 136The vegetal and herbal aromas in wine. Some things to think about when considering the threshold of aromadetection10. Friends or foes? Foxy, musty and gamey smells 148Aromas that are ambiguous, unpleasant, or faulty, and how we adapt to certain smells11. Spicy, petrol and woody complexity 161Some unusual aromas from the grapes and some woody spices from the winemaking process: but not everybodycan smell them12. The world of oxidation and reduction 175Two complementary domains of chemical compounds that contribute more layers of aroma, and some final thoughts on just how impressive and important our sense of smell isEpilogue: Putting it all together in six pairs of wines 192References 207Thanks 223Index 226