Cooking Myths (Part 3)

This one's a doozy because it goes against all logic.

Apparently, when you steam mussels, clams or oysters, the ones that don't open should be discarded.

This defies science and logic.

Dead clams are obvious to spot. They are open and they stink. In fact, a closed clam is a healthy one because it's still alive.

When you steam them, you are in fact, killing them.

Clams, oysters, mussels – they don't possess a nervous system like mammals that feels pain so for all those vegetarians given to furious and fervent anthropomorphism, this is not unlike steaming spinach. You are killing the spinach too when you steam it and it too feels no pain!

The ones that don't open are the healthiest of them all since they are resistant. A few additional minutes of steaming always does the job.

So people prefer tossing out the best clams for the dubious ones? Sounds pretty fuckin' irrational to the CC!

Cooking Myths (Part 3)

It sometimes surprises people to know that a tightly-packed refrigerator or freezer is actually much more energy efficient than a loosely-packed one.

It shouldn't be so surprising. Air has almost no thermal capacity. We've discussed that in the context of an oven but the same principle applies to a freezer.

The things that keep the insides cold are actually the walls and the food and beverage items.

That's why a packed freezer will stay cold for a long time during a power outage.

So if you have a packed fridge like the CC, you can pat yourself for being more energy-efficient.

Cooking Myths (Part 3)

There seems to be pervasive myth that if you remove the seeds from a green chilli then it loses its heat.

Except that all the heat of a chilli is in the skin not the seeds.

Remove them for aesthetic reasons but don't be under any delusion that you are reducting the heat quotient!

Cooking Myths (Part 3)

Another cooking myth is that bread is done when you pull it out of the oven.

As any good baker would know this is patently false.

This is a simple consequence of the classical heat equation (bet you weren't counting on partial differential equations showing up on this blog, huh?)

Heat flows from stuff of higher temperature to that of lower temperature.

In the oven, heat flows into the bread because the oven is hotter than the dough.

As you pull the bread out of the oven, the heat starts flowing out of the bread into the ambient air. Frequently, the very center of the bread may be cooler than its surroundings, and heat will keep flowing towards it as well. Consequently, the bread is still "cooking", and experienced bakers know to hold themselves away until the bread equalizes with the temperature outside.

Experienced bakers know that good bread will "crackle" as it cools down. The bread is contracting from being cooled and the strands of gluten are snapping as the bread contracts. Which releases even more aromatic molecules of smell.

That's what makes fresh bread irresistible but you must resist for a while before the bread has cooled down. (Otherwise, you get to eat a lumpy doughy mess.)

It's one of the sad truths of life — instantaneous gratification is a very bad thing in the world of fresh bread!

Cooking Myths (Part 2)

This series has been dormant for a couple of years but it's time to resurrect it.

One of the pervasive myths about baking is that opening the oven door makes the temperature drop "drastically".

The fact that the temperature drops is not in doubt. What's in question is the "drastic" part.

Let's start with the basics.

Air has very little thermal capacity. It's ability to hold heat is minimal if that. That's precisely why you can put your hand in a 500°F oven and not feel a thing.

Just so we are clear on this concept, try sticking your hand in 212°F water (a.k.a. boiling water) and see how you feel. It's a lot less than 500°F!!!

So what exactly holds the heat of the oven?

It's actually the walls and the floor. They have a high thermal capacity. In fact, if you want to increase the thermal capacity, you should put in a very large steel plate on the bottom of the oven, or a ton of bricks, and run the oven for a long time.

The air is largely irrelevant!

Cooking Myths (Part 1)

Welcome to a new series on pervasive cooking myths.

One of the biggest ones is that since alcohol has a lower boiling point (78.4°C) than water (100°C), all the alcohol must evaporate first when added to a dish.

Sorry, folks, it doesn't quite behave that way as every physicist and chemist possibly knows.

Firstly, in general, you need multiple distillations to separate two liquids. This is just a consequence of how molecules behave. Energy transfer and evaporation are statistical in nature not deterministic.

Secondly, ethanol and water form an azeotrope so you can never truly separate them using just distillation.

So while the rate of evaporation of alcohol is higher than that of water at 100°C (cooking temperature), there's always going to be alcohol left behind in the mixture even after extended cooking. Particularly in a closed vessel where you have both evaporation and condensation taking place.

Method	Percentage alcohol remaining
Added to boiling liquid + removed from heat	85%
Alcohol flamed	75%
Alcohol simmered 15 minutes	40%
Alcohol simmered 30 minutes	35%
Alcohol simmered 1 hour	25%
Alcohol simmered 1.5 hours	20%
Alcohol simmered 2 hours	10%
Alcohol simmered 2.5 hours	5%

(Source: US Dept. of Agriculture Nutrient Data Lab.)

Note that we're talking miniscule amounts because generally only a small amount of alcohol is added to the dish but the myth that there is none left behind is just that.