Reader Amy writes to say that some of her old family recipes call for alum, but what is it and is it really necessary? Great questions. Anyone who’s every watched a Warner Brothers cartoon has probably wondered the something similar. You know those scenes: Tweety Bird somehow manages to pour a box of powdered alum down Sylvester’s the Cat’s throat and his head shrinks up to the size of a golf ball. But what the heck is that stuff and what did people use it for?
Alum is short for aluminum potassium sulfate. It was once a common household item here in the U.S., especially during the war years when people did a lot of home pickling. A pinch of it in a jar of kosher dills or watermelon rinds kept the pickles firm and crispy. Too much and the result was a serious pucker, since alum is both an acid and an astringent (which is to say, a compound that causes shrinking or constricting of blood vessels and/or mucous membranes).
How ’bout an answer to the question, digression king? Right. Alum has another household use: as a chemical leavener. It’s commonly formulated into baking powders as a reactant along with baking soda. This is probably why it appears in your family’s recipe, Amy. Is it strictly necessary? No. You can use some other form of kitchen acid to create your reaction if you like: a little cream or tartar or a teaspoon or two of vinegar or fresh lemon juice will do the trick. Then again baking powder is a lot easier, which is the reason I prefer it.
Of course any baking powder you buy probably has alum or some close variant of alum in it, so if you’re specifically looking to avoid alum or aluminum itself, there are some non-aluminum baking powders on the market that work pretty well.
Reader Simone wants to know if there’s a nutritional difference between corn meal and corn masa (the alkaline-treated dough used for making tortillas). Indeed there is!
Though no one knows exactly how, ancient Mesoamericans long ago discovered that when you soak corn kernels in a mixture of water and wood ashes, the tough outer hulls (pericarps) can be slipped off, leaving just the starchy endosperm and oily germ. The process is called nixtamalization. Without it the Central America of old would have been a very different place.
For in the process of making their corn easier to handle and eat, Mesoamerican cooks accidentally unleashed a torrent of nutrients that would otherwise have been unavailable to them. For nixtamalization it turns out vastly increases the amount of free niacin present in corn. It also makes the protein in corn much more absorbable by the body.
What’s niacin? We know it as vitamin B3. It’s an essential nutrient, without which the body’s metabolism begins to slow down. Left unchecked a severe niacin deficiency leads to a disease called pellagra.
What’s pellagra? Well, Europeans — especially Italians — found out all about it when they imported corn from the New World but not the nixtamalization process. Poor people who subsisted on nothing other than cooked corn meal (polenta) began to exhibit skin rashes (the word “pellagra” is Italian for “rough skin”), weakness and in the worst cases dementia and death. Terrible stuff, pellagra, and it wasn’t just limited to Italy. The southern U.S. had tremendous problems with it until pellagra’s cause was finally identified in 1938.
But back to Mesoamerica. So what happened when the peoples of that region started eating corn that was suddenly rich in vital nutrients? Pretty much what you’d expect. Malnutrition decreased and populations increased. So powerful was the effect of nixtamalization, or so many historians speculate, that it allowed the tribes of Mesoamerica to grow into societies, the societies to grow into civilizations, and the civilizations to build great cities like Tikal and Teotihuacán.
Could a silly thing like a handful of wood ash dropped into a bowl of wet corn do all that? It seems it can. Quite likely, it did. Thanks Simone!
VERY good question, reader Ashley. There are certain similarities but in the end they are quite different things. Popovers are made with a batter that resembles something you’d use for crêpes. Choux batter is a more complex combination of pre-cooked (gelatinized) starch lubricated by fat (egg yolks). What you get in that case an ultra-elastic paste that can increase in volume by up to 600%. By contrast you’re lucky if your popover batter increases threefold. It’s a darn impressive feat still and all.
All that said, you can use popovers and choux in similar ways. Certainly the classic use of a popover is as a “bread” eaten with a main meal. However being hollow, popovers are great filling holders too — you can put custards and mousses inside of them, soups or stews even, especially if they’re left over and stale. A very nice application on a chilly day!
Reader Sue says her Czech mother-in-law-to-be uses the word all the time in the kitchen and she wonders what sort of dish it is. Sue, I only know this because I dated a Czech girl in high school and her mother used that word. “Ham and eggs” is what she’s talking about, and good stuff it is too. In the Czech version it’s usually all fried up in the same pan with herbs on top. Now you know!
Isn’t it bad for you? So asks reader Victoria. Victoria, the main reason pie makers use shortening (or lard) in their pie crusts is to keep the moisture content as low as possible. Butter can be up to 18% water, and that can be a very bad thing for the texture of a crust.
We talk about gluten a lot on the site and for good reason. North American gluten can be a real pain to work with, as it’s elastic in nature and tends to make pastry tough and prone to shrinkage in the oven. Gluten is always present in flour, but it takes the addition of water to “activate” it, i.e., cause the individual gluten molecules to bond to one another in a springy network. So we try our best to minimize the amount of water in the crust, especially at the start of the recipe where we’re working the dough a lot, because agitation also helps activate gluten.
If we were French we could probably find some of their “dry butter” to use, but we aren’t, so we make do with whatever soft-firm fats we can find. Normally that’s vegetable shortening, but historically home bakers have used lard. Some country bakers use 100% lard in their crusts, but that taste can be a little “piggy” for some people, especially with a sweet pie. Vegetable shortening offers a neutral flavor and brings no water whatsoever to the party.
So I guess the short answer to the question, now that I’ve droned on for so long, is that we use butter for flavor and shortening for a flaky texture. Make sense? As for whether shortening is bad for you, I’ve never believed that trans fats are bad for you (there’s not terribly much data to prove it). However if you’re worried about that you can buy trans-free shortening now. Or, for a more home-spun answer, find some leaf lard at a local farmer’s market (it’s milder tasting than store-bought lard), render it and use it! I can tell you that lard is great for biscuits too!
I’m still answering the more than 400 questions I got during my absence. I shall continue to put some of the answers up as posts, because a lot of them are darn good questions. Hope everyone had a great Memorial Day weekend by the way!
So asks reader Bernard, and I love it. Bernard, it all has to do with the fact that in the Colonial era rum was liquid currency. It was more valuable by weight than any other commodity save gold. It kept indefinitely and like the American Express card was recognized at over 15 million locations worldwide. For a short time the English government even recognized rum as money, which no doubt made banking a whole lot more fun.
As highly valued and heavily transported as it was, rum made an excellent target for privateers. What were privateers? Think of them as early military contractors: government-paid out-of-uniform toughs who sailed the high seas settling scores, exacting retribution and collecting debts on behalf of their masters. Unofficially, of course.
As you can imagine privateers tended to collect quite a lot of loot in pursuance of their duties, a bunch of it drinkable. And very often, they drank it. In fact it happened with some regularity that a ship full of privateers would eventually decide they’d just as soon keep all the booty they collected for themselves and continue on robbing and plundering on a freelance basis, at which point they became known as pirates. So that’s where the yo-ho-ho comes in.
Of course rum drinking wasn’t limited to privateers and pirates. Cargo and military ships would sometimes pay their crews with rum. And let’s face it, how many sailors were going to let that stuff sit around until they made landfall? Eventually rum wages became rum rations, a sort of fighting sailor’s fringe benefit. The American and especially British navies maintained that tradition for centuries after Colonial times. Today rum rations are passé, the practice having been discontinued all the way back in 1970.
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.
It’s the starch in the endosperm that gels and thickens liquids, but in order to work it has to be liberated from the confines of the pericarp. Sure, if you simply grind the whole kernel up into meal and immerse it in hot liquid you will get some gelling, but because much of the starch is still attached to jagged pieces of endosperm and germ, the effect will be limited.
Contrast this simple grinding with the way cornstarch is actually produced. The kernels are soaked in water for two or three days, during which time the endosperm gets very soft and the pericarps get very, very flexible. The kernels are then passed through rollers which squeeze out the endosperm (which is mostly just dissolved starch by then) and pinch off the germ. The whole mess is then rinsed and spun in a centrifuge. The starchy water spins out and is dried to make cornstarch.
What you have when you’re done is a powder that’s almost pure starch: small granules that are almost entirely free of all the flotsam and jetsam found in corn meal. Immersed in warm liquid they disperse nicely and gelatinize (thicken) beautifully, much better than meal. But then you recently found that out, reader Kati. My condolences. Better luck next time!
Over my extended absence three different readers wrote in to say they were having buttercream consistency problems, specifically with the Swiss and Italian meringue buttercreams. All three reported that their buttercream was working well for spreading and cake building, but piping was a problem. Their piped decorations were dropping and/or losing their sharp edges. Can IMBC and SMBC be firmed in any way?
I can think of two ways to achieve a firmer buttercream texture. One is to scale back the butter a bit, but just by a little, maybe 12%. That raises the ratio of meringue and gives the buttercream a bit more body. The other thing you might try is to buy higher quality butter, which tends to be firmer. Lower quality butters tend to have lower melting points, which makes them softer at room temperature. That tends to be truer in the winter months when dairy cows aren’t grazing in the fields as much, but inexpensive butter can be soft at any time of year. “Spend more money” is never welcome advice, but where buttercreams are concerned you tend to do better when you pay up a bit. That’s my best advice, gang. Anyone with further/better advice feel free to weigh in!
Reader Rob writes:
Hi Joe, I have looked through a lot of raised doughnut recipes, and very few ever seem to use milk powder as an ingredient. I assume this is for the proteins, but how come you use it whereas other recipes don’t? Maybe delve into the science behind it?
Hey Rob! Nice question. Milk powder does a few things in a baking application. As you point out it adds protein, and that along with the extra sugars can be handy in terms of getting a darker, more golden finish. It also add flavor, another nice feature especially in fast rising breads like doughnuts and white loaves which tend to be bland because of the extra-quick yeast action. However the big benefit of dry milk is tenderness. The fats and the milk solids undermine gluten formation so the finished product is less rigid than it would otherwise be. That’s especially desirable in a raised doughnut since the crusts can come out of the oil rigid to the point that they shatter when you bite into them. The longer you let the doughnuts rest the softer the crusts get, but since I generally like to hand them around when they’re warm I go the tenderizer route.
Foiling the action of gluten has other benefits for doughnuts. If the dough isn’t terribly stretchy then the bubbles in it tend not to get very big. That’s good because a big open crumb can be a pain in the neck when you fry. The big open spaces can push the expanding doughnut out into weird shapes, or create giant open cells which can break open and fill with oil. Those big cells are also inconvenient if you’re filling your doughnuts with jam as all the filling tends to pool up in one place. In general in a yeast doughnut you want a fine, fluffy, even crumb. So you see there are a lot of good reasons for milk powder in a doughnut dough.
I should add that the finer your milk powder the better as the solids and fats spread out more evenly through the dough. That translates to a finer structure that is at once more tender, fluffier, taller AND stronger. King Arthur milk powder is especially fine and I heartily endorse it. Thanks again, Rob!