Did You Just Eat That?: Two Scientists Explore Double-Dipping, the Five-Second Rule, and other Food Myths in the Lab

by Paul Dawson, Brian Sheldon

Is the five-second rule legitimate?Are electric hand dryers really bacteria blowers?Am I spraying germs everywhere when I blow on my birthday cake?How gross is backwash?

When it comes to food safety and germs, there are as many common questions as there are misconceptions. And yet there has never been a book that clearly examines the science behind these important issues—until now. In Did You Just Eat That? food scientists Paul Dawson and Brian Sheldon take readers into the lab to show, for example, how they determine the amount of bacteria that gets transferred by sharing utensils or how many microbes live on restaurant menus. The authors list their materials and methods (in case you want to replicate the experiments), guide us through their results, and offer in-depth explanations of good hygiene and microbiology. Written with candid humor and richly illustrated, this fascinating book will reveal surprising answers to the most frequently debated—and also the weirdest—questions about food and germs, sure to satisfy anyone who has ever should I really eat that?

Genres: Science, Nonfiction, Food, Health, Medicine, Medical

312 pages, Kindle Edition

Published November 6, 2018

Reviews

[Traci · Rating 3 out of 5]

An interesting look at food and food safety. Also a scary look at those subjects...I sort of want to make sure that everyone is washing everything diligently now! Then again, nothing horrible has happened in my 50+ years of eating different dishes, so hopefully I have a strong immune system - and I don't eat after folks that double-dip. LOL

Only thing is that there is a lot of science in this, namely when the authors describe in detail how the experiments were conducted. I tried to read those sections when I started the book, but after a few of times of slogging through them, I decided to skip over them. I'm not really interested in the minute details of how the sterile solutions were mixed, etc - just in what the basic experiment was, and what the results were.

Just be warned - you may want to eat nothing but PB&J sandwiches after reading this!

[Elizabeth · Rating 4 out of 5]

I don't understand why so many reviewers are hating on this book. The authors state in the instro that for maximum enjoyment you can jump around to the sections that interest you, and if you don't care to read about dilutions and incubation you can skip the "Science stuff ahead" sections.

In this book the authors design experiments to determine whether bacteria that cause foodbourne illness can be trasmitted through unsavory practices such as double dipping and blowing out candles on a birthday cake. (Spoiler alert: yes). Written pre-pandemic, the book is written in a light-hearted manner. In the midst of a pandemic, the teachings are more serious. I will never, EVER play beer pong again. It's gross.

[Carol · Rating 3 out of 5]

Received as a GoodReads giveaway. The book covers a number of common potential infectious situations, like blowing out birthday candles, putting ice and lemons in drinks, sharing popcorn, drying hands, etc. Basic takeaway is that pretty much everything is dirty and disgusting. This book might help me lose weight because I don't much feel like eating anything after reading it.

The writing is a mix. Some of it is very colloquial and easy to read, but there's loads of science-y stuff to get bogged down in. I ended up skimming through a lot of it. The epilogue has some good tips.

[Claudia · Rating 4 out of 5]

One in 6 Americans eat tainted food - and the number is estimated to be 48 million people a year since MOST go unreported. It's just a stomach ache or a touch of diarrhea. No reason to visit the doctor since it's over in a day.

After a voyage through the microbial world and types of bacteria and viruses, there are ten chapters that investigate myths and/or beliefs regarding possible food contamination and some surprising locations where bacteria reside and spread. Filled with amusing illustrations along with tables, charts and other informational facts.

Each chapter states the rule and possible origins. Any actual studies performed and what it may reveal. Then the actual experiments performed by Paul Dawson, Brian Shelton and their assistants. Material and Methods which include an in depth explanation of how samples were taken (including even the actual manufacturer of some of the samples. Results of the experiments with various charts and tables with written explanations. The chapter then ends with 'Things to Consider'.
And so the myths considered:
- The Five-Second Rule
- Beer Pong: Don't Hate the Game
- Are You Ready to Order? - - Restaurant Menus
- Blowing Out Birthday Candles, or Spraying Germs on Cake?
- Keep Your Dirty Hands to Yourself - - proper hand washing
- Hand Dryers, or Bacteria Blowers?
- Things You Put in Your Drink - - from ice to a slice of lemon
- Can I Have a Taste of That? - - sharing dishes
- Pass the Popcorn, Please
- Dip Chips and Double-Dipping

Of course, the epilogue covers safe actions to counter the five practices/behaviors that contribute to bacterial outbreaks (poor personal hygiene; inadequate cooking; improper holding/storage; contaminated equipment and cross-contamination).

In the end, the reader has been educated in a light and entertaining manner. Takeaways included being careful. Be smart. Be aware that bacteria are literally everywhere and most are not human friendly.

2019-109

[Robin · Rating 3 out of 5]

Some parts were interesting but the scientific explanations were a little too detailed for my tastes. I tended to skim over the "whys" and "how it was determined" and get straight to the "but should I..." parts. It's a bit like the TV show Mythbusters but not as entertaining and nothing gets blown up.

The bottom line is if you think something has bacteria on it, it probably does (floor, carpet, menus, birthday cake after the candles are blown out) so just be extra careful. And if you want to save yourself a few bucks or reading hours, I'll tell you there is no "5-second rule" or "1-second" for that matter. If you drop something on the floor, throw it away. You're welcome.

[Lisa Konet · Rating 4 out of 5]

I thought this was amusing, funny and horrifying at the same time. The funny? Laminated and paper menus not being wiped down between diners when g0ing out to eat. Yes, some parts of this were very scienc-y but I thought it added to reader's understanding of the book and the humor. The horrifying is eating scraped food from the floor and the air hand dryer... the germs!! OMG, so gross!

I do not think this was a five star book in my opinion, but it is definitely not a low-ranking book. The author tries to make a serious subject as funny as possible. Still recommended for the humor and funny stories.

[Amanda Z · Rating 4 out of 5]

I won this eBook through Goodreads Giveaways.

This book describes experiments undertaken at Clemson U. to teach student about the scientific method and experimentation, in the context of food safety. The best part is that it includes DESCRIPTIONS OF THE ACTUAL SCIENCE, with methods, controls, and plotted results, and statistics, which I appreciated as a PhD in the Physics side of things. I don't have much experience with Biology, but I went to a three week bio camp that had us swab toilets and grow stuff on agar plates, and do experiments with E. Coli among other things, so I found the level of detail perfect.

I think high school biology students might like the book, though they don't cook much.

As for what you will learn, everything ever you've been told is germy, is germy. Quantitatively so. I mean, the five second rule has always been a joke to excuse being gross eating floor food in polite company. But hey, there are fewer germs after 5 seconds than 30 or 60.

Fun fact: Plastic transfers more germs than paper, and salmonella will die off (somewhat) after a while).

As a scientist myself, I was mildly annoyed that the authors went though the trouble of explaining log plots, and the not use them for most of the book.

I had some questions for further experiments. Can you wipe off food scooped from the floor and remove lots of germs? Asking for a friend....

[Amber · Rating 3 out of 5]

Have you ever read a book and thought "this could have been a Reader's Digest/Cracked/Buzzfeed article instead?" I probably would never have picked this book up myself but it was gifted to me because of my culinary interests. Having taken a ServSafe course, I knew most of the answers to the questions already, and a lot of them are common sense: yes, double-dipping and sharing utensils spreads germs and who thought beer would have enough alcohol to kill germs from the floor? Even back in college I didn't know anyone who played Beirut by actually drinking from the cups the ball landed in; they always used cups of water and did shots or gulps of whatever they were already drinking. However I did go to school with a lot of scientists. If you really want to know the scientific details of how the safety of different food scenarios is studied, by all means pick it up. Anyone else will probably skim past the details (though I do commend the authors for including them; if nothing else it's an interesting look into the scientific process).

[Lindsay · Rating 3 out of 5]

I won this book in a GoodReads giveaway. It was interesting to read all of the experiments these scientists have conducted looking at germs and eating. They give you the nitty gritty details of their experiments, which gives them credibility. They also use humor to lighten the mood. Overall, it definitely makes me want to wash my hands more, share food less frequently, and skip the hand dryer.

[Jane · Rating 3 out of 5]

Meh. Nothing in here was surprising, except maybe that restaurant menus are grosser than you thought. There was also no discussion of being fluid bonded with another human. Is double dipping around someone you kiss really that bad?

[Jo · Rating 3 out of 5]

Sometimes the technical talk (generally in the "Science Stuff Ahead" sections) got a little sloggy, but overall, this was a good example of taking science and relating the experiments and their findings in laypeople's terms. I do think that they're going to have a hard time convincing people who do things like follow the 5-second rule to change their behavior. I may also have to follow this one up with Eat Dirt: Why Leaky Gut May Be the Root Cause of Your Health Problems and 5 Surprising Steps to Cure It, just to see if they say anything about floor-food ('cause, y'know, dirt).

This is the boring part of my review, so feel free to stop now. Thoughts I had when reading about some of these experiments:

Chapter 1, The 5-second rule: Transfer is easy, but opposing the 5-second rule assumes that there's something to be transferred. If I mopped my kitchen floor yesterday and drop a cracker today, I'm going to eat the cracker. A dollop of pudding, however, I will pass on.

Chapter 2, Beer pong: I am so glad I don't like normal-people parties.

Chapter 3, Menus: I generally use utensils after ordering from a menu, so I don't touch my food after handling said menu, thus making this moot. (Until it isn't, I guess.)

Chapter 4, Blowing out birthday candles: Sure, you're spraying germs on the cake, but you're spraying germs on the guests when you talk to them, so is this really worse?

Chapter 6, Hand dryers: I've always preferred paper towels just because hand dryers are loud. But again, how many germs are being sprayed that you aren't already breathing by being in the bathroom?

Chapter 8, Can I taste?: I split a couple of entrees with a colleague last week. We each ordered one, cut ours in half, put one half on another plate, and traded second plates. If I eat something someone else has bitten, the someone else is my boyfriend. (My parents were included until I moved out on my own.)

Chapter 10, Double-dipping: I only double-dip if I'm sharing with my boyfriend OR everyone who will use the dip has a chance to say, "Gross, don't." (This is possible in my world because to me, a party is myself, my boyfriend, and two friends.) I will flip-and-dip. (Dip one end of a fresh chip, eat that end, flip the chip around and dip the other end. I suppose there is risk here if I didn't wash my hands. But gross, I always wash my hands.)

[M · Rating 4 out of 5]

Lots of eeeeuuuw facts about double-dipping, 5 minute drops, sharing desserts, and never beer pong

The audiobook narrator is very good, but sometimes it’s not easy to follow. The Kindle version is well-organized and has an easy-read layout with decent graphic art. I read a lot of medically-related articles and several online science magazines, and this book does a great job of consolidating information about “germy practices.” And hey, you CAN skip the “sciences” parts, which the authors warn about.

With the current pandemic, most health warnings concentrate on aerosolized transmission. In other words: viruses hitching rides on droplets/aerosols breathed out by talking, yawning, singing, by or just breathing. That’s why masks, distancing, etc.

This book emphasizes how we share and exchange bacteria and viruses via our hands—handling things, touching our mouths, tasting a friend’s food, etc. Like holding restaurant menus in our hands. Sharing a big bucket of buttered popcorn. Friends taking turns tasting their gelatos. Dipping veggies in Ranch—when others double-dipped. Yucky lemons in your iced tea. Bar tenders grabbing garnishes like lime slices, cherries, etc. with their fingers. And don’t even BEER PONG!

[John Biddle · Rating 2 out of 5]

I thought the book was extremely repetitive. It would have been much better as a magazine article. It's great that they did all these experiments in an exacting scientific manner, but the repetition of the techniques over and over again is just too tedious. I saw in another review that the authors encouraged people to feel free to skip the science parts if they wanted, but to me that meant the authors knew they went overboard; they were right. And, I was listening to the audiobook, not easy to skip ahead to the next section.

There were no surprises here, no new information, just a more scientific argument for what we already knew. I expected more entertainment, more humor, but there was virtually none. There was also a complete lack of perspective. Constant counts of how many bacteria were transferred, but nothing to give you a feel for how likely you were to get sick from it. They would coat something with bacteria and then check to see how much if any got transferred under controlled circumstances. But how am I to know how that initial state compares to the real world? Very disappointing.

[Candice · Rating 5 out of 5]

Well researched, clear and concise.

This book starts about with an overview of the biology of microbes and food-borne illness. The main book is divided into three sections; surfaces, air &water and transport mechanisms. Within each section are chapters addressing a specific topic such as blowing out birthday candles and the spread of microorganisms.

Each chapter begins with an overview of known research, with full citations listed in the notes section at the end of the book. In standard research form the question is stated followed by descriptions of materials and methods, the experiment and the results. Charts, graphs and other images with supporting information are included. Finally, there is a real world interpretation of results.

The writing style is engaging and often funny. Everything is clearly marked so you can choose to read the interpretation without the experimental details if you prefer. If you aren’t already a germaphobe you may reconsider while reading this book.

Highly recommended.

[Linda A · Rating 5 out of 5]

This book is essential reading. It's not designed to scare you, as one amazon reviewer claimed. It's good science applied to everyday situations, explained in a non-intimidating way. Each chapter tackles questions we all have: hand-washing hygiene, our own and that of food handlers; paper towels vs. air blowers (surprisingly, the answer is to use paper towels, by a wide margin!); hand sanitizers (hint: anything less that 70% ethanol is useless); is it ok to take a taste or swig of someone else's whatever? Also, each chapter is clearly divided into sections that identify methodology and the science it's based on, so you can skip those parts if you want, since the results are laid out in language any non-scientist can easily understand. They don't dictate behavior, they simply lay out the questions and results and leave it to you to make your own decisions, although there frequently is an obviously "right" choice! Full of clear and engaging illustrations, diagrams and graphs, the book is fun to read while providing helpful insights.

[Lynne · Rating 3 out of 5]

In these current times, when we all want to avoid picking up a virus, this book provides a look at the world of microorganisms around us. That world is impressive. Using laboratory techniques these two scientists look at food preparation, restaurant menu surfaces, double dipping at parties and such things to give a true picture of how we are surrounded by multitudes of bacteria, viruses and other tiny things that can have positive or negative effects on our lives. The drawings included are delightful in themselves. For those who might want to replicate these laboratory experiments, the authors give the outlines of their lab work in detail. They are thorough. I am not experienced with chemistry lab equipment and techniques, so I probably would not be duplicating this work, but the book is detailed enough that one could do so. The book concludes with a chapter that outlines practical techniques for food safety and ways to avoid food borne illnesses. Food borne sickness is far more common than I realized!

[Laura Demeuse · Rating 2 out of 5]

If you want a book about the details of scientific experiments around food and pathogens, this book is for you. All this book does is tell you over and over again that pathogens are everywhere and you always have a chance of touching or ingesting a pathogen- duh. Never does it talk about the actual statistical data of what it means to be somewhere known to have an increased likelihood of there being pathogens because of unclean surfaces or food touching the floor, but just that in layman’s terms - it’s gross. Humans have been around for millennia without worrying about using Lysol on every surface they see, washing fruits and vegetables before eating them, etc and yet they managed to survive. What about the miracles of our immune systems to fight off these pathogens even if we decided to spend our weekends playing beer pong? Or what about our environment now that has changed due to chemical and industrial movements that might increase one’s chances of falling ill? These all should have been addressed in this book to give people a clear picture of what the true risk is.

[Toni · Rating 3 out of 5]

Quite an interesting read, Did You Just Eat That? delves into the questions of how quickly food is contaminated in all kinds of different scenarios. I will admit to skimming or even skipping over paragraphs that became way too technical for me but doing that did not detract from the more interesting aspects of this book. My favorite chapter - Chapter 6 - paper towels vs. air blower hand dryers. The results of their observations were astounding. After this read you may look differently at how you eat your food and with whom. Some alternatives may seem hopeless and you might just want to continue on but pray for a very healthy constitution to get you through each day unscathed! Made me get out my antimicrobial wipes out from under the sink to a permanent place on the counter top! They do give good suggestions for survival at the end of the book. Lots we already know but still eye opening in the long run!

[Cris · Rating 5 out of 5]

I was given this book to read and review for a specific book club.

Do you believe in the 5 second rule? Do you ever share a bucket of popcorn at the movie theater? Do you double dip? Have you ever thought about the bacteria you have swapped or left behind? Have you ever thought about the kinds of bacteria?
I’ll say I learned more about bacteria than I might have wanted...but I think it’s something everyone should know! The way the book written is easy to understand. They explain the test they did, the results they received and explained the results so everyone can understand them!

[Babajaga · Rating 3 out of 5]

I won a Kindle version in a Goodreads giveaway. This book confirmed that many of my fears concerning food safety and germs are substantiated. The authors undertook a series of scientific experiments documenting occurrence of germs in common situations where people tend to underestimate the potential danger. While I wasn't too keen on reading the detailed descriptions of each experiment, I understand that it was necessary to include them as a scientific reference. Overall, I would recommend the book to general public as it is a good source of information on the subject of germs.

[Kara of BookishBytes · Rating 3 out of 5]

Don't double dip. Don't eat anything that has touched the floor. Wash your hands. Clean your kitchen work surfaces and tools. If you don't do these things, you'll ingest extra germs. We all know this. I hoped the book would provide engaging stories or present this material in a particularly fun way. Unfortunately, it didn't. I also hoped that it would be a good book to give to kids. Nope on that.
It simply isn't engaging enough. I did learn that restaurant menus are particularly germy. Otherwise, this book was a disappointment.

[Rachael · Rating 3 out of 5]

I found it very fitting to read this book during my lunch breaks.

On the one hand this book provides some good information. On the other hand, sometimes it could come across too much like a dissertation. So I could easily see people skipping the "science stuff ahead" portions of each experiment.

Sometimes the information was of the obvious nature and sometimes their dire warnings came across as the ramblings of someone who feels the need to live in a plastic bubble.

[Erikka · Rating 3 out of 5]

Way too much detail and repetition, but the general point was very interesting and a must-read for anyone in food service. Also, their science is unobjectionable--every experiment is described to its utmost and, given the subject matter, there can't be a better phrase to use than "it was detailed and described ad nauseum". Because, trust me, when you finish this, you will be nauseated. A+ science, C- interesting read.

[Jbussen · Rating 3 out of 5]

OK. Interesting. But I ended up skipping to the parts I wanted to read. There is the technical information on the experiments and how they came to their conclusions. I liked that. There was some humor in the authors writing style, I liked that also. Some of the topics I liked:
Beer pong & menus. Hand blowers vs. paper towels. Community food like at a party, or say popcorn. Oh and I forgot, the germs on a cellphone. Glad I read but wouldn't read twice.

[Emma James · Rating 4 out of 5]

I came across this book while actually looking for a different one, but it was intriguing from the title! I found it to be a good mini-refresher of microbiology, and found the experiments to be funny and witty, but also very thoroughly researched and done. My favorite experiment was the 5 second rule. The wording can get dull if you don't quite understand or want to read how they exactly did the experiments, but it was good to hear their findings and I found it to be thought provoking.

[Kristin Henderson · Rating 4 out of 5]

Clever book to answer those questions you really don't want to know the answer to. Now, I don't abide by the 5 second rule, and I don't want lemons or limes in my drinks, thank you very much. And yes, my husband is right about no double dipping. Let's just say there's a lot of ewwwwing going on while reading this book. Enlightening!

[Erin Triplett · Rating 2 out of 5]

This book is actually fine, but wasn’t what it presented itself as—an entertaining exploration of food myths. I thought it would be a fun addition to our homeschool science program. It’s actually very technical with some “witty” pictures and pop culture references thrown in almost as an afterthought. Small child tapped out before we were finished with the introduction.

[Morgan Wagner · Rating 3 out of 5]

More sciencey than expected. It included all the the experiments used to determine their results. If you are interested in knowing every last detail, statistic, and experiment procedure, then i give it five stars.
However, i was not; so i skimmed through and read the results and facts about each situation given. Still an interesting read.

[Cynthia Nicola · Rating 4 out of 5]

Very interesting book! From the labs at Clemson University came this disgusting look into double-dipping, beer pong, hand washing, and the like. I must admit my eyes kind of glazed over at the scientific parts but I was riveted by the results. There is such a thing as urine and fecal mist. Ewwww!!

[David Hansen · Rating 3 out of 5]

They spend a ton of time discussing lab methodology and equipment which would probably be fine to skip over in the print edition, but made the book feel tedious in the audiobook. It is not reflect poorly on the story telling and the fun discoveries of the book, but the audiobook listener should be aware.