There’s a lot of debate about what, if anything, to add to eggs before scrambling them, and experts don’t agree on the subject. Most folks do what their moms did, and only sometimes question it.
According to Harold McGee in his book On Food and Cooking, adding liquid to eggs for scrambling or omelettes will produce a moister, somewhat softer mass of coagulated egg proteins. Although a lot of the white in an egg is water, the proteins can hold somewhat more liquid than they do in the plain egg. However, the amount is not very large – 2-5 teaspoons for scrambled eggs, and 2-3 teaspoons for omelettes. Note that this does not apply to foods like custards, quiches, or the like, which have a much greater liquid to egg ratio.
Water, of course, adds no flavor, and milk doesn’t add much, so either of those will simply extend the eggs a bit and make them softer. In addition to making the cooked eggs softer, butter, cream, or a soft cheese like cream cheese or goat cheese will flavor them as well. Liquids should be added when the eggs are beaten, and little bits of butter or soft cheese should be added after the eggs have begun to coagulate and form curds. Extra egg yolks boost nutritional value and enhance the flavor; use one extra yolk for every four eggs.
With regard to other flavor-enhancing additions, more acidic cheeses like Parmesan or Cheddar should be added to scrambled eggs when they’re done cooking, or the eggs will be watery. Any vegetables like tomatoes or mushrooms should be pre-sautéed until dry or again, the eggs will be watery.
Other things are added to scrambled eggs, too, which you might not suspect. If you’re gluten intolerant or have celiac disease, you might want to question scrambled eggs found on food service buffets. In order to extend the eggs and prevent their browning and/or leaking liquid, anything from a mixture of flour and milk (the milk helps to dissolve the flour), corn starch, biscuit mix, or béchamel (white) sauce may be added. Some people claim it improves the taste of the eggs as well as the texture. I don’t know about the taste, never having knowingly tried any of these (scrambled eggs from a chafing dish – ugh), but texture is a matter of technique more than additives.
We were required in cooking school to prepare scrambled eggs in the classic French manner before moving on to other egg cookery. This involves gently melting butter in a double boiler, then adding and continually stirring the beaten eggs over low heat with a wooden spoon until they form a creamy mass with virtually no curds. It takes about half an hour, an interminable amount of time when other cooks around you are doing more interesting tasks. The result? I love French food, but didn’t find this worth the time and effort involved. Giving it another go this morning for purposes of research, I reached the same conclusion. I prefer my eggs with more discernible, firmer curds.
So what method do I prefer for scrambling eggs? I turn up the heat to medium-high and work quickly. Break the eggs into a bowl, salt them lightly (too much salt toughens the proteins), and beat just until the whites and yolks are homogenous. Bits of white in the finished dish – it’s usually the chalazae, the ropey connective tissue that connects the yolk to the lining membrane – is unattractive and unappetizing. Add liquid of your choice if you like, but very little.
Heat a skillet proportionate to the number of eggs. A 7″ or 8″ skillet is good for up to four eggs; use a larger one for more. Melt a good pat of butter in the pan, swirling it around the interior. Pour in the eggs all at once, and immediately begin scraping and folding them from the sides of the pan to the center. Lower the heat and continue scraping and folding until the eggs are almost completely set, but remove from the heat while they’re still shiny. If they’ve lost their gloss, they’ll be dry. Add additional salt to taste and pepper, and serve immediately on warmed plates.