Cooked at a long time for a low temperature, egg whites will turn brown!

We’ve all cooked a hard-boiled egg: simmer an egg eight to twelve minutes and you’re half way to an egg salad sandwich.  But what happens if you cook an egg for eight to twelve HOURS.  It’s possible and the results are spectacular.

The History

I came across the concept of “long-cooked eggs” while doing research on Sephardic cuisine for the Lower East Side Tenement Museum as part of a program called “Meet Victoria. ”  In this program, visitors get a chance to interact with a costumed interpreter playing the role of a 14-year-old immigrant who lived on the Lower East Side in 1916.  Victoria, the girl in question, is Sephardic Jewish: sephard meaning “of Spain,” which is where Victoria’s ancestors lived until the Spanish Inquisition of 1492.  After leaving Spain, Sephardic Jews settled all around the Mediterranean, but much of the population ended up in Turkey.

When it  comes to Jewish food, one of the aspects I find most interesting is Sabbath cooking.  One of the prohibitions on the Sabbath, the holy day of Saturday, is lighting any kind of flame (there are 38 others).  That makes providing a hot meal on Saturday a rather difficult thing, particularly in the 19th century.  But there were some clever loopholes: a fire lit on Friday, before the start of the Sabbath at sundown, could be allowed to burn until the next day.  As a result, Jewish cultures developed a  slow-cooked stew that could sit on the stove overnight: cholent for Ashkenazic Jews and hamin for Sephardim.  (side note: baked beans, which traditionally cook overnight, were developed for the same purpose in American Christian culture, to save work on Sundays).

Sephardic Jews also developed another snack for Saturday:  huevos haminados.

Harold McGee and Long-Cooked Eggs

I stumbled across an essay by kitchen scientist Harold McGee on long-cooked eggs.  He offered a great paragraph on the cultural origins of the dish:

In his Sephardic Cooking, Copeland Marks reports having eaten ‘Jewish eggs’ among Calcutta Baghdadies, in Morocco, Tunisia, Turkey and Greece.  He gives a Spanish version via Salonica, huevos haminados, that calls for tea leaves, coffee grounds, and onion skins in the cooking water, as well as a bit of oil and vinegar.  The eggs are brought to a boil, then cooked over a low heat ‘for at least 5 hours, preferable 6’.  Marks notes that ‘…The longer one cooks them at a very low heat, the softer they become instead of the reverse….’The whites acquired a soft beige color…and the yolks are very cream and pale yellow.  The flavor is delicate and excitingly different from eggs cooked in any other way.’

And in his seminal work On Food and Cooking: The Science and Lore of the Kitchen, McGee adds this:

During prolonged heating in alkaline conditions, the quarter-gram of glucose sugar in the white reacts with albumen protein to generate flavors and pigments typical of browned foods (see the explanation of the Maillard reaction). The white will be very tender and the yolk creamy if the cooking temperature is kept in a very narrow range, between 160 and 165ºF/71–74ºC.

Scienceey.  I didn’t have the capabilities, or frankly the patience, to test this recipe as throughly as McGee did.  But I was curious what would happen if I dumped a half-dozen eggs into my slow cooker.

The Recipe: Huevos Haminados (Seven Hour Eggs)

Gently places six eggs into a slow cooker.  Cover with water.  Set cooker on “low” for seven hours.

When seven hours is over, remove eggs from water with a slotted spoon.  Run cold water over them until they are cool enough to handle; I like to use a colander for this job.  Crack, peel, and serve warm.

The Results

McGee tested the eggs at several temperatures and with different additives in the water.  He found that the whites of the eggs always turned a brownish color, whether or not they were cooked in plain water, or in water with other additives.  The egg proteins develop a nutty flavor and the egg itself because creamy.  Coffee and olive oil penetrate the egg-shell during cooking and increase the nutty flavor of the egg and also dye the outer shell, while onion peels only dye the shell but don not affect the flavor.

The moment I cracked my slow-cooked eggs, my mind was blown.  The whites had turned a distinctly brown color.  My reaction may have been our of proportion with the event (I think I kept screaming at my roommate “It’s brown! It’s brown! It really worked!) but it really seemed like a magic trick of nature.  I had made magic.

I took a bite: meat.  The egg tasted like a pot roast.  Closer to the yolk, I encountered the distinct, nutty flavor I had read about in McGee’s article.  Like hazelnuts and walnuts. My egg didn’t have a creamy texture, but I suspect they were a tad overcooked.

Brown. Meat. Egg.  Who would have expected that?