A Pinch of Culinary Science
Anu Hopia and Erik Fooladi
A Pinch of Culinary Science
Boiling an Egg Inside Out and Other Kitchen Tales
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Library of Congress Cataloging-in-Publication Data
Names: Hopia, Anu Inkeri, author. | Fooladi, Erik Cyrus, author.
Title: A pinch of culinary science : boiling an egg inside out and other kitchen tales / Anu Inkeri Hopia, Erik Cyrus Fooladi.
Description: Boca Raton : CRC Press, Taylor & Francis Group, 2019. | Includes bibliographical references.
Identifiers: LCCN 2018051394| ISBN 9781138611306 (hardback : alk. paper) ISBN 9780429878442 (pdf) | ISBN 9780429878435 (epub) | ISBN 9780429878428 (mobi/kindle)
Subjects: LCSH: Cooking--Popular works. | Food habits--Popular works. LCGFT: Cookbooks.
Classification: LCC TX652 .H6477 2019 | DDC 394.1/2--dc23
LC record available at https://lccn.loc.gov/2018051394
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Contents
Preface
Acknowledgments
1 The real thing? - The chemistry and psychology of an apple pie
2 Boiling an egg from the inside out
3 In the beginning there was an egg
4 Mussels on acid
5 Sausage engineering
6 Mustard, fiercely yours
7 The potatoes that refused to become tender
8 Gravlax and a pinch of salt chemistry
9 The art of heating
10 Cold skillet - juicy fish
11 Tempering the meat before cooking, …or maybe not
12 Cooking pits - prehistoric cooking meets science
13 White wine in cooking should always be dry, right?
14 Taking stock of broth
15 Salt shapes the pasta
16 You can see it, hear it, taste it, and feel it - what is it? It is the taste of food!
17 Can you cut down on the salt without affecting the taste?
18 Physics takes the cake
19 The great Norwegian porridge feud
20 The inevitable dishes
Glossary
Bibliography
Index
Preface
For a natural scientist, food is usually molecules, plant cells, and phases of matter such as liquids, solids, and gases. Chemical reactions in the kitchen dictate the result, physical phenomena such as heat play important roles and the whole thing ends up as a meal and an experience.
No surprise that we, two food-loving chemists, would choose such an entrance to the book we write. Who we are would surely put its stamp on the way we talk about the food we cook and eat. But you don’t necessarily need to have an academic degree in chemistry to harness these chemical substances and reactions. This is clearly visible every day as skillful chefs, professional or amateur, apply their experience-based knowledge handed down from one person to another all over the world. While we are professionally excited about all the scientific knowledge that chemistry offers to us, we are aware that food is much more than the sum of its molecules. Food is also a part of our common and personal history, woven into the identity of every human being. It is part of our culture, of our great and small emotions and experiences. With food, we communicate, we make friendships, and we show love and affection. We hope this can be seen throughout the book as it would be sad if the food was reduced to molecules and salts—mere outcomes of chemical reactions and the laws of physics.
Often, the most commonplace transformations in the kitchen have prompted us to ask why things happen as they do, and this has been the starting point of most chapters in this book. In the context of our open and informal scientific food workshops, arranged in both Finland and Norway, we have approached various questions from both theoretical and practical points of view with the aim of understanding food, meals, and joys thereof. We have not only read books and scientific publications, but we have also carried out experiments together in the attempt to reach the very heart of the phenomena. Thus, we do not want to just convey funny anecdotes or fun facts about food chemistry or to pretend that we know exactly what’s going on at the molecular level in food. Some things we know, but much we do not know, and we are curious and will never stop asking questions. Therefore, we try to ask questions about issues that have not already been described in the research literature, can be found in cookbooks, or by a search on the Internet. And often when we look for the answer to a question, we find only part of an answer, and, in addition, two new questions appear. Rather than giving unambiguous answers, we would like to invite the reader to consider these kitchen mysteries with us. This way we hope to pass on curiosity about food, sow seeds for the reader’s own inquiries in the kitchen, and promote diversity in food and food culture.
Two other persons have been important along this journey. Chef Tatu Lehtovaara, who has shared his expertise and experience in the art and craft of the kitchen, has been involved in creating and implementing the food workshops from which most of the examples in the book are taken. Most of the book’s recipes are by Tatu’s hand, and he has also raised a significant number of interesting questions that we ourselves wouldn’t have envisaged but have been shown to be both significant and thought provoking.
The other important person in the book is graphic artist Aki Scharin, who has dazzled us with an imaginative journey into the world of food structures and molecules. Although Aki’s illustrations usually set out from food and molecules, often, at some
point, they begin to live their own lives. Through his work, the food and its molecules develop to become part of our common visual heritage. As a result of this mutual effort, this book of cooperation and friendship has emerged.
Helsinki and Volda
Anu Hopia and Erik Fooladi
Acknowledgments
We have already thanked chef Tatu Lehtovaara and graphic artist Aki Scharin, who both have played an important role in making this book into what it has become. Tatu has been a driving force in the startup and implementation of the food workshops in Helsinki; he has contributed to the planning of every workshop. With Aki we have been working for almost ten years. Even without any science background, he has a unique ability to visualize fundamental natural and scientific phenomena, and his references and connections move in the most unlikely and unthinkable directions. The many discussions over illustrations have been exceptionally stimulating, probably for all three of us. His skills and imagination both amaze and delight.
Many others are also to be thanked for their contributions. A special thanks to all you who have participated in, and hosted, the food workshops in Finland and Norway. For your interest and active participation, for contributing with your knowledge and experience and for giving us such interesting questions to explore. This should be clearly visible for those reading the book.
We have received help and input from many while writing the various chapters. We would like to thank chef Arto Rastas (65°C egg recipe), Maria Planting (meringue discussions), Ismo Korhonen (discussions on steaming mussels as well as cooking for and conducting the porridge tasting), Christophe Lavelle (discussions on heat), Guro H. Rognså (white wine discussions), Gunnar Aurdal (music descriptions), Liv Marit Mathilde Aurdal (discussions on archeology and prehistoric cooking), Pasta Factory Helsinki Oy (specially made pasta for a workshop), Nanna Rintala (translation of Finnish excerpts from the flavor chapter into English), Pekka Lehtonen (knowledge on wine), Øyvind Andersen (dishwashing discussions) and the three informants Liv Brekke, Margit Fet and Jostein Fet (traditions related to porridge).
The workshops described in the book have been conducted in various places in and around Helsinki, and in the Sunnmøre region in Western Norway: Stadi Vocational School (Helsinki, Finland), Klippfiskakademiet (Ålesund, Norway), Borgund Upper Secondary School (Ålesund), Heureka Finnish Science Center (Vantaa, Finland), Alko Oy Training Center (Helsinki), Teurastamo Kellohalli (Helsinki), E. Ahlström Showroom (Helsinki) and Unilever Suomi’s test kitchen (Helsinki). Thank you very much, all of you—it has been a wonderful journey and we hope the cooperation may continue.
Our respective families have experienced both suffering and enjoyment as a result of our work with this book. Thank you for always being there!
Anu Hopia and Erik Fooladi
1
The Real Thing? The Chemistry and Psychology of an Apple Pie
On a dark and rainy October afternoon, a group of our gastro-scientific food workshop participants gathered to enjoy some apple pie, and to discuss the role of molecules in our food. The Chef and the Chemist had each baked a delicious apple pie for the event and the participants were asked to decide and tell which they preferred and why. Both apple pies were baked with the same type of commercially available pie crust, the difference was in the fillings. While the Chef made his pie filling by sautéing Granny Smith apples in butter and sugar, the Chemist made hers trying to keep the best possible control of which molecules went into the pie: she added carefully weighed amounts of specific molecules to a filling that had never been in the vicinity of an apple. The apple-like taste in the Chemist’s mock apple was created using the main chemical substances that makes apple taste like apple: sugar and fruit acids. A structure similar to apple compote used in many apple pies was achieved using salted crackers soaked in the sweet-sour liquid.
Mock apple pie
Ingredients
Ready-made pie dough
500 ml water
250 g sugar
2.5 g malic acid
2.5 g tartaric acid (these fruit acids are available in home-brewing and wine stores and some supermarkets)
30 round salted crackers (e.g. Ritz)
Cinnamon
Butter or margarine
Procedure
1. Mix the water, sugar and acids and heat to a boil.
2. Place the salted crackers carefully into the boiled mixture and heat gently for about 3 minutes until the crackers have swollen and absorbed the liquid to the full. Keep the crackers under the liquid but do not stir, thus avoiding breaking the crackers. When swollen they will gain a structure and mouthfeel resembling apple compote.
3. Press the pie dough into a 24–26 cm round baking tin.
4. Use a sieve to let excess liquid drip off the crackers and move the “compote” carefully onto the pie dough (the pie easily becomes too moist).
5. Sprinkle with cinnamon and add some lumps of butter/margarine.
6. Bake the pie in a medium hot oven (225°C) for approximately 30 minutes until the crust and filling have developed a nice, golden brown color.
The two apple pie twins were cooked in the same oven and then served for blind tasting by the participants, unknowing of the fact that one was made with apples and the other without. The participants were asked to describe the two pies, and then report which pie they would prefer. The nine participants constituting the evening’s taste panel were, however, not only asked about which they preferred, but also but also why they did so. Not surprisingly, the pie made of real apples disappeared from the plates rapidly and was the one preferred by the majority: the votes were seven for the Granny Smith version and two for the “mock” version. The majority reported that the Chef’s Granny Smith pie had a better structure and stronger apple flavor, and was simply “better tasting.” The two choosing the Chemist’s pie acknowledged this to have better appearance and nice moistness. This rather depressing result for the Chemist made us wonder whether the mock apple pie could be improved to compete with the “real” one, or whether the latter would always be preferred regardless of cooking skills and recipe. After all, the result might be a matter of cooking skills rather than recipe.
It was surprising that none of the participants questioned the nature of the Chemist’s mock apple pie. The majority preferred the “true” pie, but they still accepted the apple-free pie to be an apple pie. All the important apple pie characteristics were present: sweetness from the sugar, crisp sourness from the fruit acids, and nice and moist apple compote-like structure from the softened crackers. Even many of the characteristic elements of apple pie aroma were there: cinnamon and the caramelized flavor from heated sugar and butter. For obvious reasons, the apple flavor was rather weak: the fruit acids are not volatile and do not contribute any apple aroma. What if we had added a drop of some of the organic esters that are major aroma compounds found in apples?
All in all, after thorough discussion, the participants considered the mock apple pie to be a decent alternative in case you get visitors allergic to apple or if you have forgotten to buy apples (and by chance had crackers, malic acid, and tartaric acid lying around). But if you ask us, the fact that it is possible to make a mock apple pie is motivation enough in itself to make the attempt.
What makes an apple pie authentic? Cooking with pure molecules does sound like a very modern, and even cold, issue and the discussion very often ends up around food additives and unwanted substances in our food. However, apple pie without apples is not a new invention. On the contrary, numerous mock apple pie recipes from the late 1800s are found in old cookbooks, and by a quick internet search. In these old recipes, mock apple pies were prepared at purest using dry crackers, sugar and tartaric acid to create an apple illusion. Sometimes apple or lemon juice was available and could be used to enhance the flavor. After all, even during times of scarcity, people still longed for familiar comfort foods and maybe an apple pie would lighten up life even more than in times of abundance. Housewives were quite innovative
indeed, but how little apple can you accept in order to call it an apple pie? Where do we draw the line? The mock apple pie prepared “molecule by molecule” was not a true apple pie, because, according to common food legislation, you are not allowed to mislead the consumer by incorrect wording. As a manufacturer you wouldn’t be allowed to sell the 19th century, or great-grandma’s, mock apple pie under the name of “apple pie.”
The psychology of eating a mock apple pie. What do you feel about the notion of eating an “apple pie” where the apple flavor is represented by a mixture of malic acid and tartaric acid? Or what if it was made using 2-hydroxybutanedioic acid and 2,3-dihydroxysuccinic acid? Would it in a sense be “wrong,” making “artificial food” in our very own kitchen similar to those fruit flavored sweets and candies that can be bought in shops and supermarkets? Undoubtedly, these issues stir the emotions in many of us as we, through media, read and hear that we should rather make “pure food” from scratch, avoiding what is often termed “processed food” and foods containing many additives.
Moving into the landscape of emotions, we turn to the psychologists rather than chemists to help us understand what is going on in our minds. In 2009, University of Michigan researchers Hyunjin Song and Norbert Schwartz published an intriguing research article that sheds light on the relation between additives and emotions. They asked respondents to read ten names of food additives and rate them according to the experienced degree of risk associated with eating them, from very safe to very harmful. The results showed that respondents rated the names that were hard to pronounce as more hazardous than those with easy-to-pronounce names. In the same study, the researchers asked respondents to rate names of roller coasters according to which they thought would make them feel most sick. In this case, they arrived at the exact same result: if the name was difficult to pronounce, the respondents felt the rollercoaster would make them feel sicker. Consequently, the researchers named their article, “If It’s Difficult to Pronounce, It Must Be Risky.” Words that were difficult to pronounce were associated not only with “risky,” but also with “new.” In our apple pie context, if we use the two names from above, 2-hydroxybutanedioic acid and 2,3-dihydroxysuccinic acid, when listing the ingredients, some might feel less well eating it, even though these names are simply the formal chemical names for malic acid and tartaric acid. After all, malic acid is the major acid in apples and tartaric acid the most predominant acid in grapes (in all Nordic languages, the two compounds are indeed called the equivalent of “wine acid” and “apple acid”).
A Pinch of Culinary Science Page 1
