A simple (visual) guide to eggs
>> January 23, 2011 –
eggs,
infographic,
science,
visualization
>> Update on 3/30/11: Thanks again to all those who provided great feedback. An updated version of the infographic had been added below and you can read more about it here. The infographic is also available for print here.
When I got a question asking about the different labels on eggs and shortly thereafter had a brunch-time discussion about how to order eggs, I realized that it was time for another Culinaut infographic (check out the previous one on the dangers of cooking with teflon).
So here's my attempt at capturing egg basics in an infographic guide. For simplicity, I stuck to chicken eggs in their most common forms. The top of the graphic covers info relevant to buying eggs from a store, and the bottom has some of the basic egg cooking/ordering options. It's also worth noting that the sizes, grades, and farming methods here are based on US guidelines and differ in other countries.
Updated version of infographic based on reader feedback (read more about it here):
Beyond the Basics
Over the course of researching data for this guide, I came across tons of great information. Some of it was just fun trivia, there were some great tips on how to cook a better egg, and some really made me take a hard look at the ethics in eating. Unfortunately, a lot of those details didn't make it into the infographic, so here are some that you might find interesting:
- Brown, white, and blue?
Brown and white eggs are pretty common, but did you know that there is a type of chicken, the Araucana, that lays blue eggs?
- Expert approaches to cooking eggs
Ever wonder why hard boiled eggs can get that unsightly (but harmless) gray-green ring around the yolk? It's actually the result of a chemical reaction between the sulfur in the white and the iron in the yolk. Longer cooking and high temperatures tend to produce more of the sulfide. Jacques Pepin shows how he hard boils eggs in here on his More Fast Food My Way series, all of which can be found on YouTube. This includes some clever tricks like making a pinhole in the shell before cooking to release pressure, and leaving eggs in cold water for longer so that the sulfur dissipates and you hopefully get a less stinky egg and no green ring.
For a more meticulous and scientific approach, Serious Eats's J. Kenji Lopez-Alt has a great guide to perfect boiled eggs as well as a clever egg taste test that explores the different types of eggs. Similarly, Cooking for Geeksdescribes various methods for cooking an egg and the effects on the egg protein as you progress along the temperature scale. And for a thorough understanding of eggs, look no further than Harold McGee's classic On Food and Cooking,
which devotes all of Chapter 2 to the history, biology, chemistry, and cooking of eggs.
- Egg safety
Eggs should always be stored in the refrigerator. To prevent food poisoning from bacteria like salmonella, On Food and Cooking
- Farming
Farming practices are probably the most confusing area regarding eggs (at least that's how I felt) due to the complexities and ambiguities in US egg farming standards. There are always exceptions, but generally speaking, it seems that egg cartons that aren't labeled with a specific farming method were probably factory farmed. This still seems to be the most common farming method for eggs and raises the most health and ethical questions, as systems such as battery cages (photos not for the faint of heart) are often used.
It turns out that there aren't really any regulations in the US around labeling an egg as "cage-free" or "free-range". Thus, you hear the stories of Omnivore's Dilemmafame, where eggs are labeled as free-range even though the chickens only had access to a tiny outdoor patch. If you're looking for the most humane eggs, the Humane Society has a helpful and more comprehensive guide to egg farming methods.
There are plenty of other ways to cook an egg which I didn't get into this time around, like omlettes, quiches, tea-eggs, or pickled eggs just to name a few. We'll have to save those for a future post. Til then, have an eggsellent time cooking! (couldn't resist just one egg pun …)
Infographic Sources
On Food and Cooking by Harold McGee
http://www.humanesociety.org/issues/confinement_farm/facts/guide_egg_labels.html
http://www.ces.purdue.edu/extmedia/AS/AS-518.pdf
http://en.wikipedia.org/wiki/Chicken_egg_sizes
http://www.seriouseats.com/2009/10/the-food-lab-science-of-how-to-cook-perfect-boiled-eggs.html
Full disclosure: The Amazon links are referrals that help fund the tea that fuels this blog.
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Adorable infographic! <3
My favorite post yet! :D
Thank you! Was thinking about you when I made this post - a guide for you would be much simpler ;)
Love this! It's so cute yet informative!
The Cornucopia Institute is doing a great job researching egg suppliers and dairy suppliers for quality. Check your eggs and dairy out here:
http://www.cornucopia.org/2010/09/organic-egg-report-and-scorecard/
What is being shown as over boiled, aka thick gray yokes, was described in some cookbooks as being an older egg that was subject to more oxidation.
why does the egg grad scale range from AA -> B instead of B -> AA. I thought that healthier, better fed chickens (mostly the Humane/Organic) tended to produce higher quality eggs. If I'm not wrong about that, then karma as well as regulation and cost would mean they B -> AA is more correct.
Very nice graphic! Im wondering about the eggs labeled "omega 3" that I see in the grocery store. I've seen the same brand with some of their boxes labeled "omega 3" and others without, so it doesn't seem they are simply saying that eggs are a good source of omega 3. Are they fortifying them? Thanks!
so is AA the best or the worst? thanks for this great guide.
brilliant. love this. its going up in my kitchen :)
Cool and useful but what's the unit of measure on the eggs, i.e. a medium egg is .88x what? Thanks!
Also the graphic isn't clear that terms like "cage free" don't mean anything and organic eggs do not mean the chickens were cage free. I'd recommend that all readers check out the Cornucopia Institute's report Scrambled Eggs to learn more. http://www.cornucopia.org/2010/09/organic-egg-report-and-scorecard/
@pate: You're right the AA eggs are the best quality, and one would think those come from the healthiest hens. The data for this graphic is based on the US standards, where the grade quality system is independent from farming method though (as opposed to some European countries where grade is tied to farming method).
When I made the graphic, I actually meant for the karma/regulations/price arrow to refer to just the farming methods section directly above the arrow, but not the egg grades or sizes. I now see how that can be a little confusing and I'll see if I can make it more clear in V2. Thanks for pointing it out!
@bertabetti: Good question! I ran out of room to include the omega 3 eggs on this graphic. You're right that eggs aren't necessarily a go-to source for omega 3. The ones that are labelled as omega 3 eggs are acutally from hens that are fed an enriched diet (usually things like flax seed and kelp) which then make the eggs much higher in omega 3. So if you're looking for omega 3, it's best to get the eggs labeled as such.
@Laura Matthews: AA is the best quality egg - it has the firmest white and yolk, which then makes for the prettiest looking egg if you're frying or poaching. Glad you enjoyed the guide!
@MarilynB: Great points - Wikipedia actually has a breakdown of egg mass by size in various countries here: http://en.wikipedia.org/wiki/Chicken_egg_sizes. I ended up focusing more on relative size as compared to a large egg (medium = .88 of a large egg) in my guide because most recipes use large eggs as a standard. Thus, the relative sizes help in figuring out how to substitute eggs.
Thanks for the link to the Cornucopia Institute's report - that looks like a great resource. The link above to the Humane Society's guide also provides an overview of the animal welfare implications of egg farming methods.
The font and colours are so light that this entire article is impossible to read.
@Anonymous: Thanks for the feedback about the type. I've made some tweaks that hopefully help. If you're still having trouble with it, would you mind sharing the type of display/device you're using so that I can troubleshoot some more?
@culinaut(from Anonymous): It does look a bit better. Thank you. I'm on a MacBook Pro, but I'm also in my late 40s and my eyes don't work as well as they used to. Or it could be that it's daylight now, I'm not sure... :)
In all seriousness, the infographic is beautiful and I can now see it when I magnify it, but the lack of significant contrast between the small/thin font and the light-blue background is still an issue for my eyes.
Thanks again for the great info.
Culinaut: Love this! I would be interested in printing this for use as art in my kitchen. Would that be alright? Would there be a charge?
@Laura I'd love for this to be an addition to your kitchen! Some folks have expressed interest in poster prints, and it's something I'm looking into, but I'm still figuring out the best way to go about it so it would take a little time. If you're interested in that, feel free to drop me an email at culinaut[at]gmail[dot]com and I'll keep you updated. If instead you'd like to just print out the higher-res image that's linked to in this post, please feel free to go ahead - thanks so much for asking!
The arrows suggest white eggs come from white chickens and similarly for brown eggs and brown chickens, which I believe is incorrect (so does Wikipedia).
Regarding the presentation, I first read it as saying white eggs were grade AA and brown eggs with grade B -- maybe more separation would be clearer.
@Xan: Thanks for making these points/suggestions! According to the Purdue U. paper referenced above, the general correlation between egg color and chickens is in the ear lobe color: chickens with white ear lobes lay white eggs, those with reddish ear lobes lay brown eggs. In that paper, they mention that one of the most common white egg laying breeds is the "White Leghorn" and good brown-egg breeds are "Golden Comet" or "Red Sex Link" hens, so I used images of those breeds of chickens as references for my infographic. I see though how the result makes it look like correlation is feather color instead. I'll have to think a bit more about how to make that more clear - need to do some research on what chicken ear lobes look like :)
As mentioned in the update above, thanks again to all those who provided great feedback. An updated version of the infographic can now be found here: http://culinaut.blogspot.com/2011/03/visual-guide-to-eggs-v2.html. It is also available for print from Zazzle here:
http://www.zazzle.com/a_simple_visual_guide_to_eggs_poster-228621926987397113. Note that the product link defaults to the largest (and thus most expensive) size - be sure to check the print options on the right sidebar. Proceeds go to charity.
as a former short order cook an overeasy egg has a runny white and runny yolk, an over medium egg has firm white, runny yolk