Why do you cook a roux?


LOVE that question, reader Molly. Indeed, a mixture of melted butter and flour should in theory have plenty of thickening power just the way it is. Why bother to cook it? The primary reason is texture. An uncooked roux yields a thick sauce, but one that has a vaguely mealy mouthfeel. That’s the result of the flour granules in the mix, which are big enough that they register on our tongues. The result is sometimes described as a “starchy” taste. A few minutes’ exposure heat causes the flour particles, which are nothing more than bundles of stick-like starches, to start shedding molecules. As that happens they reduce in size to the point that we can no longer detect them.


How important is sifting?


Reader Deb asks if it’s necessary to sift the flour for an upside-down cake, or whether a vigorous whisking will suffice. I advise a full sift myself, for cakes especially, but everywhere lightness counts: biscuits, sponges, pancakes, tea breads, the list goes on.

It’s true that some modern bakers consider sifting to be little more than a ritual, and an outdated one at that. I disagree, though I will admit that sifting isn’t nearly as critical for the home baker as it once was.


Why doesn’t corn meal thicken?

Reader Kati wonders why cornstarch (corn flour) is so effective as a thickener when corn meal makes such a poor thickener. She alludes to some recent kitchen disaster that resulted from an attempt substitute one for the other. Reader Kari, I feel your pain. The answer lies in the way the two flours are processed.

Corn kernels are the seeds of the maize plant. As such, each has a tough outer covering known as a pericarp, which is similar to a bran layer on a wheat berry. Each also has a fatty germ which when pressed yields corn oil. The majority of the kernel is the starchy endosperm.


So what is the tangzhong method?

Anyone who’s ever made a pudding cake has, for all intents and purposes, employed the tangzhong method. It’s the same basic idea: you add a pre-prepared starch gel to your batter/dough and what you get in return is a finished product that’s higher and lighter than it would otherwise be, that retains more moisture and that has a very tight and even crumb. The big difference of course that in a tangzhong (essentially “soup starter” in Chinese) there’s no sugar or flavorings in the mix — just flour and water combined at a ratio of 1-5 and cooked to roughly 150 degrees Fahrenheit.

But then what does the tangzhong gel do in the bread dough? It’s a very good question since baked bread is already a starch gel to some extent. But let’s back up a bit. Flour (white flour) as you’ll recall is nothing more than the finely ground endosperm of the wheat berry. Think of the endosperm as a dense pack of very long and stringy starch molecules all packed in together. Grind it and you get endosperm granules, which I think of as tightly bound bundles of sticks.


What Steam Does For Bread

Reader Melody writes this about steaming loaves of bread:

Steaming honestly doesn’t seem to help that much. My baguettes still have a thick and dull crust. Am I doing something wrong? I spray more often than you do. If you can talk a bit about this that would be really helpful. I’ve been talking to our local baker but I think he’s getting a bit tired of me.

Melody, I would be delighted, for there are a lot of misconceptions about steaming bread. It’s widely thought that steam produces thin, crispy crusts on breads. That isn’t strictly true. What steam actually does is delay the formation of a thick crust by moistening the surface of the bread and keeping it supple. This allows the loaf to expand more than it otherwise would in a drier oven. The result is a higher rise and more open crumb since the crust doesn’t harden immediately and hold the expansion in. This is actually the main benefit of steam.


Making Lemon Tea Bread

Whaddya know. I made lemon tea bread without poppy seeds and the sky didn’t fall in. I don’t know when in human history lemon and poppy seeds became inseparable, but I wish a mad scientist would build me a fusion-powered DeLorean so I could go back in time and stop it. This tea bread is rich, tangy and tender with a crispy, almost candy-like crust. Best of all you don’t have to pick anything out from between your front teeth after you eat it. Start yours by assembling your ingredients, preheating your oven to 350 degrees Fahrenheit and greasing two 9″ x 5″ loaf pans. Line those suckers with parchment paper.


Is sugar really “dry”?

Reader Chelsea writes: I’ve got what I hope is an interesting one for you. Yesterday I was baking a quick chocolate cake to serve as dessert. As I whisked up the batter, I could tell something was wrong: it was very, very thick, more like cookie dough than cake batter, and not the deep dark […]


Instant Flour

Instant flour is the go-to of meat gravy makers everywhere, at least here in the States. Instant flour is pre-gelatinized, which means it’s been steamed to initiate the breakup of the starch granules into individual starch molecules. The process isn’t completed because at least some of the bigger granules are needed for starch thickening to work. The great thing about instant flour is that you can just pour it into a hot liquid without making a slurry first. Clumps don’t form, the thickening happens virtually, well…instantly, and delivers a result much like a traditional roux but without the added fat. Handy stuff if you have a hot sauce that needs to be thickened just before serving. Of course like other starch thickeners you don’t want to boil it too long, knowadimean?



Like cornstarch tapioca is a “pure starch” which means that compared to wheat flour it has no protein, bran or germ in it and as such packs more of a thickening punch. Tapioca comes in “pearls”, in granules (pieces of pearls) and in flour form. All can be used as thickeners, though the smaller the pieces the more readily they dissolve and the faster they act. Tapioca flour, my preference, dissolves almost instantaneously and because it gels at a lower temperature than cornstarch you can see the results immediately if the mixture is above 140 or so degrees Fahrenheit. Like other starch gels, however it also “un-thickens” when overcooked.


Wheat Flour

Plain wheat flour is a go-to thickener in the kitchen, especially where sauces care concerned. In combination with butter or oil it becomes a roux, which is the basis of classic béchamel. White flour, most bakers know, is the ground endosperm of a wheat berry, the endosperm being the energy storehouse of the seed. Moisten the seed and enzymes in the endosperm go about breaking down the long chain starches that are stored there into simple sugars. These sugars fuel the sprout (contained in the germ) as it grows.