How to Mess Up Enzymes

Reader Hermes asks, since I mentioned that heat treating is only the “most popular” way to denature (wreck) browning enzymes in fruit, what other methods are there? A great question I’d be happy to answer, Hermes.

Acids do a great job of stopping browning enzymes from going to work on phenols. Depending on how strong they are they can slow down the the functioning of an enzyme, stop it from functioning altogether, or denature (gank) it. Ascorbic acid (lemon juice) and acetic acid (vinegar) are popular for this purpose.

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Why bother poaching pears…

…when you’re just going to cook them in the oven anyway? A good question, reader Toni. The answer is: enzymes. Pears will turn brown when they’re baked if they aren’t poached first. That browning is a result of enzymes that activate when the flesh of the pear is cut.

In an uncut pear these browning enzymes (polyphenoloxidase and peroxydase) are kept inside special compartments in the flesh of the pear, away from both oxygen and the compounds these enzymes commonly interact with, molecules called phenols. The trouble comes when those tiny structures are damaged by, say, cutting or bumping the fruit. At that point the enzymes are freed from their little holding cells and start to run wild. With plenty of oxygen at their disposal (which they need in order to do their job) they hop from phenol to phenol breaking each one into pieces. The resulting wreckage is a variety of smaller molecules, some of which are melanins, or brown pigments. The longer cut pear flesh is exposed to oxygen the browner it will get until all the phenols on the cut surface of the flesh have been sliced and diced, and the flesh is a mottled tan.

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Paint and Its Consequences II

I liked the job on the house so much that I asked the crew to do the kitchen. They showed up yesterday, again a week ahead of schedule. Who are these people? But I can’t cook or bake at the moment. The kids can’t believe their luck that they get carryout two night in a […]

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Seasoning a Pan With a Wooden Handle

Reader Annemarie writes:

This is off topic for this question, but something that you might be able to help me with. A few months ago I won a “Le Crueset” cast iron saute pan, with a wooden handle. I know that you are supposed to season the pan before use, but I’ve only been able to find methods that involve putting the entire pan into the oven. I’m reluctant to do that with the wooden handle. Can you suggest a method? I’ve tried just heating oil in the pan, but that doesn’t do the trick.

Hey Annemarie! First, congratulations on a nice pickup! This is an obvious question, but did the pan itself come with any instructions? I ask because Le Creuset is obviously a very respectable brand, as such the odds are very good that it’s pre-seasoned and all you need to do is start using it. In fact “just using it” is good advice just generally for cast iron. People get overly obsessed with seasoning these days. Plain ol’ use will accomplish the task quicker than you might think.

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Why do cheesecakes crack?

Reader Rick is sick and tired of having to disguise the cracks in his cheesecake with sour cream toppings and fruit and wants to know what he can do about it. Rick, I have a few ideas.

Cracks in cheesecakes are caused by temperature problems, and are usually a result of one region of the cake heating faster than another. Large cheesecakes are especially crack-prone since the areas closest to the rim of the pan cook and firm up first. If this happens too abruptly the outer portion of the cheesecake can shrink and pull away from the softer inner portion.

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New Oil, Old Oil

Apple fritter lover Emma wants to know whether it’s OK to combine fresh oil with older oil when you’re frying. She says she keeps seeing recipes that specifically instruct her never to do that. I’ve seen those as well, Emma, and all I can think is that none of these folks have done very much frying, for not only can you combine old fry oil with new, you absolutely, positively should.

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Strained Relations

Apples and pears are like two siblings with nothing common. Oh sure they may have sprung from the same family, grown up in the same household, but when it comes to their disposition, passtimes and taste in friends, they couldn’t be more different.

Both the pear and the apple call the mountainous areas of modern-day Kazakhstan home. Both traveled the Silk Road west to Europe and east to China and Japan. Both are so-called pome fruits (members of the rose family along with quinces and Asian medlars and loquats). They’re climacteric and heterozygous (see The Great Apple Crap Shoot for more on that). Aside from that, though, they’re barely on speaking terms.

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Food Scientist Top 10 List?

Reader Dan writes:

Hi Joe. You say that George Washington Carver is “one of” your favorite food scientists. Who are some of your other favorites if I may ask? Can you give me your top ten?

I’m not sure if Dan is on the level here or if he’s having me on. But it just so happens I do have several food science heroes, whose dreamy portraits adorn my walls. There’s Nicholas Appert, the inventor of canning, he’s really the grandfather of modern food science. Alfred Bird, inventor of stable baking powder and instant pudding (custard). There’s Otto Rohwedder, the sliced bread guy, chocolate chemist Coenraad Van Houten, good ol’ Louis Pasteur, you can’t forget him. To tell you the truth “food science” encompasses so many different

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