There is plenty of lore in the kitchen, and a fair amount of myth, too. Here are four common cooking myths that are in need of a bit of a rethink.
Myth 1: you should cook with the same good wine you’re drinking
The main reason we use wine in cooking is to provide an umami, savoury taste, which doesn’t depend on what specific bottle or even variety of wine you’re using. There are aromas from the wine that come into the dish, but not even the best sommeliers could tell you the specific vintage or side of the hill that a wine came from after it’s been boiled with onions, garlic, carrots and a kilogram of beef.
You can bet your butt that the fancy French restaurant you’re eating at didn’t use the same Chateau La-whatever they’ve matched with your meal to make the demiglace or the coq au vin.
Don’t tell the wine snobs, but I’ll sometimes even use wine that’s gone “bad” to cook with.
Wine goes “bad” by oxidation and souring and while that might make them terrible to drink, a little of either isn’t necessarily a bad thing for cooking. Deliberately oxidised wines such as sherry and madeira are prized as cooking wines, and a touch of sourness can freshen dishes in the same way the old French saucier’s trick of a splash of vinegar before serving does.
Trust your nose – it’s a better assistant in the kitchen than any rigorous set of rules.
Myth 2: blanching vegetables keeps them crisp
Blanching is a process of cooking (usually vegetables) by quickly boiling, then chilling by plunging into iced water. Some say this helps to retain texture and colour, but sadly it also makes the vegetables cold, watery, and robs them of seasoning.
You don’t need to blanch vegetables at all. The technique reached popular heights through French restaurant mise en place in the nouvelle cuisine movement of the 1960s and 70s, when crisp vegetables started to come into vogue on the continent. It was used to prepare vegetables before service, when they would often be sauteed with additional seasoning.
A better way to cook vegetables at home is to skip the iced water completely. Boil your vegetables in a nage (a flavoured broth) or even just seasoned water and remove them before they’re cooked through, allowing residual heat to finish the cooking. They won’t lose their crispness or colour because they won’t be overcooked, and they’ll be a lot tastier.
Myth 3: you should salt eggplants before cooking to draw out the bitterness
Salting to reduce bitterness works in two ways. Salt draws out moisture and water-soluble bitter compounds (anthocyanins in eggplant, which oxidise to bitter quinones) along with it, and salt also inhibits our ability to taste bitterness.
But eggplants aren’t really very bitter any more. Heritage varieties of eggplants are more bitter, but decades of agriculture have bred much of it out of the modern fruit. Raw eggplant today tastes a bit like underripe apple.
Another suggested benefit of salting is that it draws out the moisture from the eggplant, which changes the texture and helps it to cook faster. Continue salting your eggplants for that purpose if you want, but you can draw the moisture out even faster, collapse the spongy texture and dramatically reduce your cooking time by just whacking your pieces of eggplant in a microwave for a few minutes.
Heating the eggplant in this way also stops any bitterness from forming because the enzyme responsible for producing bitter taste (polyphenol oxidase) is rapidly denatured over about 50C.
Myth 4: you need to use unsalted butter in baking
Before you throw your hands in the air in disgust, I’m willing to admit this one is a bit controversial. But to every midnight baker who’s thrown salted butter into a recipe and had it turn out perfectly fine – you are not alone, and you don’t have to live with your secret shame any more.
Most adherents to the “rule” suggest that using unsalted butter allows greater control over the amount of salt added. Technically true, but the amount of salt in salted butter is remarkably consistent between brands (“generally between 1.6 and 1.7%”, according to the US National Dairy Council).
I think most sweet baking recipes could use more salt than they let on. Recipe writers are too timid to exceed the anecdotal “pinch” despite the fact that a little more salt would be a big improvement to the taste of most cakes, scones, muffins and icings.
More important to baking, however, is butter’s moisture content. Here’s where it gets tricky. Butter is an emulsion of water and fat, and most countries specify that butter must have at least 80% butterfat content (most brands are between 80% and 85%). The moisture content of butter varies roughly between 12% and 18%. That variation in liquid can be a substantial difference to the gluten formation when baking with wheat flour.
In general, salted butters often have a slightly higher moisture content – but that’s not the full story. There is a far greater variation between brands than there is between salted and unsalted. The long and the short of it is, the brand of butter you’re using matters a lot more than whether it’s salted or not.
In the interests of full disclosure, I should add that I usually bake with unsalted butter, but that’s because I usually buy unsalted butter for all uses. I think it’s much more important for savoury cooking than sweet, where the salt content has to be controlled more closely.
For most home cooking, however, baking with salted butter is going to be perfectly fine in just about any circumstance, and particularly so for icings and other applications when you aren’t using wheat flour.