I've had numerous requests to put up some sort of table comparing American flour types with their French, German and Italian counterparts. And while I'd love to comply, I'm not sure that much real data exists on that, for all the reasons I spelled out last week. However, because there are no lengths I won't go for my readership (as long as it's, you know, convenient for me), I spent the weekend scouring available sources for the following information:

American all-purpose = French Type 55 = German Type 550 = Italian 00

American pastry flour = French Type 45 = German Type 405 = Italian 00

American bread flour = French Type 80 = German Type 812 = Italian Type 1

American whole wheat = French Type 150 = German Type 1700 = Italian "Wheat"

Now then, I know I have an increasingly international readership here at joepastry.com, so if anyone wants to correct and/or add to what I've started here, by all means, weigh in.

People love to make Italian breads — pizza especially. And for that, the serious ones tend to seek out Italian flour, the kind that's known as Italian "00" flour. As to what exactly that is, there is quite a bit of confusion. Search around the web a bit and you can find all kinds of animated discourse on the subject:

It's HIGH-gluten flour specifically made for pizza!

No, it's LOW-gluten flour that's used for pastry!

No, it's flour that's only used for bread!

No, it's flour that CAN'T be used for bread!

I'll do my best to settle some of this, because it is a touch complicated. First off, Italian flour makers (like all flour makers on the Continent) don't classify flours in terms of their gluten content. Rather, they classify them by ash content and by grind. Italian Type "2" flour is a coarsely ground high-ash flour (what we in the US might call a "meal"). Types "1" and "0" are medium-ash, medium grind flours for hearth breads. Type "00" is the low-ash fine grind that's used for many whiter breads (including pizza) and some pastry. In general it's roughly equivalent to our own all-purpose flour. It's fairly high in protein (gluten), and good for a lot of things.

So then if it's high in gluten, why do some pizza makers substitute extremely LOW gluten flour for Italian "00" flour in their pizza crust recipes? The answer is that not all gluten is created equal. Some varieties of wheat contain gluten that is both hard and springy (like our own hard red wheat), and make very elastic doughs. Other types contain gluten that's hard but not springy (Italian durum for example) which produce doughs that are firm but not very elastic. Most Italian flours are of the latter variety, which is why most real Italian pizza makers don't do this with their dough, but instead prefer to stretch their pizzas into shape.

What does it all mean? It means that Italian flour has "bite" but not "chew". American high-gluten flour has both "bite" and "chew", but that's not necessarily a good thing, depending on who you talk to. Some American pizza makers, hoping to more closely approximate a Neapolitan-style pizza, opt to eliminate the "chew" of American flour by employing a low gluten flour, sacrificing the "bite" in the process. It's a trade-off that some people really like, for instance me, though I definintely opt for the genuine article when I can get it.

Hope than makes sense.

The thing that most Americans want to know when they talk about French flour is: what can they do to approximate French "Type 55" flour? That's the kind that's most commonly used for baguettes and even many pastries (it's akin to an American all-purpose). That's an extremely difficult thing to do for reasons I discussed below in the post "What's the deal with ash content?". However there several other important differences between American and French flour that make a direct equivalent an all-but-impossible to thing to formulate using commonly available components.

But Joe, flour is just ground-up wheat, how different can the two really be? The answer might surprise you. For one, French flour is milled and mixed to different standards compared to American flour. Typical French bread flours, as I mentioned at the beginning of this long series of posts, are what are known as "straight" flours. A straight flour is what you get when you grind a wheat berry, remove most of the brand and germ and a) don't sift it into lots of different grades and b) don't mix it together with other grades from other batches (as American millers usually do). The result is a flour that's coarser than a normal American bread or all-purpose flour.

The character of the protein (gluten) is also quite different in a French flour, not nearly as elastic as the kind you find in American flour. Though French Type 55 flours routinely list a protein content of around 11.5 percent, they perform more like a medium-protein American flour, around 9.5 percent. That puts them on par, as I mentioned before, with American all-purpose flours. Plenty of bakers try to replicate baguettes or other French breads with high-gluten flours (or mixtures of low and high gluten flours) but the experts are mostly in agreement that too much American gluten is bad for a good French bread.

So when you get right down to it, there's not much about American and French flours that are the same, other than the fact that they're all flours. They're different types of wheat grown in different places, under different conditions, then processed differently and milled differently. The end result is that they behave differently from one another in the same types of applications. Does that mean it's a hopeless task to try to make a good baguette out of American flour? By no means. Simply select a good, hard all-purpose flour (preferably a Northern one made from a hard red winter wheat) and you're at as good a starting point as any baker on this continent.

In the same way that Americans talk of flours in terms of their protein content, Europeans talk of ash content. But what is this mysterious "ash" and why would you want it in your flour? The answer is that the ash isn't in the flour, it what's left over after a set quantity of flour (100 grams, I think) is burned — burned in such a way that all the starch, bran and germ is eliminated, leaving only the charred remains of the non-flour matter behind. The ash is then measured to determine how much of this non-flour matter the original batch of flour contained.

But just what is this "non-flour matter"? "Mineral content" some sources will tell you, "material related to fiber" others say. Both of those terms are essentially true, if non-specific. "Ash" is really a catch-all term for all sorts of non-harmful, non-starch items and/or impurities in the flour, which range from the naturally-occurring minerals in the tissue of the wheat itself to pieces of wheat stalk, bits of dirt and flecks of stone, right up to things like insect parts and rodent hairs.

What...disgusted? Don't be, because American flours have all those things too (if you don't believe me, read this sometime...just do yourself a favor and do it on an empty stomach). We just don't like to talk about it, which — at least I theorize — is the reason we talk about things like protein levels and extraction rates instead.

What can you learn from the ash content of flour? Quite a lot, really. If you consider a wheat berry as you might, oh say, an onion or an egg — it's a thing that's made up of layers. Since wheat is grown outdoors, it stands to reason that the outer layers of that berry will contain more impurities than the inner ones (also most of the naturally occurring minerals are found in the outer bran of the berry). Grinding and sifting is a process by which those outer layers are removed, so the more you refine a flour — the more you purify it down to only the very inner, starchy endosperm — the fewer non-flour items you're going to have in the finished product.

And so it is with European flours, where a high ash content (say, around 1.5 percent) is going to be a whole grain flour and a low ash content (0.3 percent or less) is going to be a cake flour. If this sounds a lot like what we know in America as an "extraction rate", it is. However because different wheats naturally accumulate more minerals and "non-flour matter" than others according to what type they are and where they're grown, it's not a perfect comparison. But it's close enough for jazz.

Why can't American flours simply be graded this way as well to make things easier on all of us internationally-minded bakers? It's been tried. However it turns out that there are fundamental differences in the way Americans harvest and store wheat compared to Europeans. For example, we dry our wheat to a greater degree than Continentals do, which is one of the factors that throws the calculations off.

I'm no expert on Continental flour, however I know enough to know that it's a darn confusing business trying to puzzle out an equivalency when you're working with a European recipe. The next couple of posts will shed some light on what some of the differences — and similarities — are between American and European flours, and (hopefully) provide a base level of knowledge for those who wish to pursue the subject further.

Pumpernickel flour is a bit of a one-trick pony in the kitchen, though I've seen it used for crackers and even cookies at times. As you'd expect, it's a very coarse blend of whole grain rye and wheat flours, designed to create dense loaves of that splendid ethnic delicacy known as pumpernickel bread. How dense is pumpernickel flour? Up to four times denser than a standard whole wheat flour, if that gives you a feel for it. The coarse grind approximates the rough-and-tumble milling of the peasantry in the East European countryside of old. Just remember when buying pumpernickel flour that they don't call it "pumpernickel" for nothing.

Rye isn't a wheat at all, though it is a grass (Secale cereale) that produces a grain. That grain is useful in many of the same ways that wheat is useful, but truth be told, you've really gotta love rye if you want to make things out of it.

Why? Because unlike rye's housebroken cousin, wheat, it resists coming to heel. For one, rye grain has the nasty habit of germinating (sprouting) before it can even be harvested, which means that the enzymes stored in the germ of the seed have already become activated. Why is this a problem? Because enzymes digest starch. Their job is to break down the long-chain starch molecules stored in the endosperm into energy-giving sugars that the sprout can use to grow. This isn't a big deal from the standpoint of endosperm consumption, since there's still plenty left for us humans when we finally get around to harvesting it. However it does mean that the flour that's eventually made from the grain contains copious amounts of those same active enzymes. Mix that flour with water, and the enzymes continue their work, digesting starch at an accelerated rate, undermining a dough's ability to rise.

Rye bread's rising ability is further compromised by the fact that rye's protein profile is different from ordinary wheat. Whereas wheat contains ample amounts of both gliadin and glutenin (the two components of gluten), rye flour has gliadin and glutelin, a protein that lacks glutenin's ability to form end-to-end bonds. No end-to-end bonding means no long, stretchy gluten networks, no stretchy gluten networks means no (or limited) bubble-holding ability, no bubble-holding ability means all the gas and steam escapes, and well...you get the idea. This is why most rye breads are made from both rye and wheat flour, a mixture known as maslin.

All is not lost in the dicey world of rye, however, for rye grain does contain one unique ace-in-the-hole: a gummy cell wall goo called pentosan gum. And while one of pentosan gum's effects is to even further undermine gluten formation, the gum itself traps and holds gas bubbles, contributing to rise. Pentosan gum also traps and holds water molecules, creating a bread that is at once moist and less inclined to staling. Thus even oddballs have their virtues (ask my mother, she'll tell you).

One word of warning about pentosan gum: if you knead a rye dough for too long the gum leaches out of the rye granules and turns the whole dough into a giant sticky mess. No matter how much more flour you add you can never un-stick it, because more rye flour is just more fuel for the proverbial fire, as it were.

Look for rye flour in light, medium and dark varieties. As with wheat flours, the darker the shade, the more of the bran and germ that's been left in it. Organic rye flour is rare, but can be found, and is excellent for getting bread starters going. The reason has to do with the premature germinating that rye is famous for. Sprouted grain is a magnet for yeasts, mold and bacteria (all of which are seeking a place at the table for endosperm banquet), and are very handy when it comes to beginning a culture.

Invented by the Reverend Sylvester Graham in the mid-1800's, graham flour has all the base components of whole wheat flour in it: germ, bran and endosperm. What distinguishes it is way it's ground. Graham believed that in order to be properly absorbed by the body, the endosperm of the wheat berry must be very, very finely ground. So, like conventional millers he separated it out and ground it to a powder-like consistency. But because he also believed that wheat germ and bran were most healthful when consumed in relatively large pieces, he ground them separately and only slightly. The result, when he mixed the whole mess back together, was a coarse meal that journalists of the day compared favorably to sawdust.

It made heavy bread (because the big bran pieces kept gluten strands from forming) and still heavier crackers. Just the tonic, so Graham believed, for quashing our unhealthful desires for white flour, meat, sugar, spices and sex.

Durum is a unique species of wheat, the hardest of all the species we eat (up to 17% protein). The word itself means "hard" in Latin, and in fact not only is it chock full of protein (gluten), the character of that protein is extremely firm. No wonder, then, that it's so good for making things like pasta (but it's also terrific in rustic breads, flat breads and pizza crusts).

While durum is virtually synonymous with central and southern Italy, it wasn't the Romans who brought the crop to the Mediterranean. Rather it was Islamic conquerors (who owned pretty much everything east of Constantinople and up into Spain starting in about the 8th century). They were well acquainted with durum, having grown quite a bit of it in the Near East. And while Italy itself was never occupied by Islamic forces, durum soon spread there since it grew so well under hot, semi-arid conditions. To this day, durum is a major crop in Italy, though we grow quite a bit here in the US as well.

Most people know durum under it alternate name semolina, which isn't the name of a grain but a grind. Semolina is most often a coarse grind of durum, though semolina (essentially "small bits") can also be made from softer types of wheat, in which case it's known as farina (or Cream of Wheat, for all you hot cereal lovers out there).

In this coarse form, durum semolina is used for everything from pasta to couscous, tabbouleh, kibbe, bulgur, injera, and as an ingredient all sorts of gruels, soups and stews. And in fact that's what most of the global durum crop is used for. Comparatively little of it is ground into flour, which is why proper durum flour can be difficult to find. When buying durum, look for the words "extra fancy" which denote that it's fine enough for use in bread and pizza doughs.

Reader Sandra writes in to ask about protein (gluten) percentages:

(King Arthur) has that sort of information on their website somewhere, I'm sure (I've never gone hunting for it), but what about standing in the aisle of the grocery store? Is there a way to look at the nutritional information label and figure out the percentage?

I believe you can estimate the protein levels of various flours by the nutrition labels, which are required by law on every packaged food product these days. Taking this as an example, you can see that the amount of protein is listed in grams per serving close to the bottom there (13), and the total number of grams that make up a serving (125) up at the very top.

Divide 13 by 125 and multiply by 100 (if my remedial grade school math serves me correctly) and the result is 10.4, which is entirely plausible for this sample flour, which is probably an all-purpose. I tried the same thing with my bags of self-rising biscuit and whole wheat flours and got 6.7 and 11.8 respectively. That's right in the target zones for those kinds of flours. Of course the best information will always come straight from the manufacturer, since as I said, there are some non-gluten proteins in some flours, especially those that contain more of the bran and germ. But this system should do in a pinch!

Instant flours (like Wondra) are very interesting things, low-gluten wheat flours that are extremely handy for thickening sauces (especially gravy before a turkey dinner!). What makes them "instant"? Simply the fact that they're cooked ahead of time so as to cause the starch granules to swell and gelatinize. Then they're dried again. The process is akin to what's done to "minute" rices, since it allows water to penetrate the starch granules that much quicker the second time around. Because instant flour dissolves so quickly, it's a terrific alternative to standard flour as a thickener (which tends to create lumps when it's added to a liquid).

Stews, soups and sauces, however, are just the beginning of what can be done with instant flour. Some pastry makers swear by instant flour as an alternative to cake flour when formulating a made-from-scratch pastry flour. Since instant flour isn't bleached heavily, it doesn't have an acidic aftertaste. And because it won't rise at all, it helps keep pie crusts flaky.

Self-rising flours are generally cake or pasty flours that have leavening and salt already formulated into them. Other than that, they're the same as other flours. I tend not to buy them very much unless I'm certain I'm getting them from a store with high turnover, since the chemical leavening loses its potency over time. The effectiveness of the leavening also falls off very rapidly after the flour is opened (in just a few weeks), so unless you're a high-volume biscuit or cake baker, you might want to just make your own. To replace a self-rising cake flour, simply add 1 1/2 teaspoons of baking powder and 1/2 teaspoon of salt per cup of cake flour. To replace a self-rising biscuit flour, add the same ingredients to the same volume of pastry flour.

Pastry flour is something you'll almost never see in stores, though quite a few cookbooks call for it. Which, you know, is aggravating. The idea is that it's not so low in protein (gluten) that it can't stand up or rise, but not so high in protein that it will make your biscuits or pastry doughs tough. It's made from conventional wheat and is around 8 percent protein, just a step up the ladder from cake flour, which weighs in around 6 or 7 percent. Make your own pastry flour by combining cake flour and a national brand all-purpose flour in a 50-50 ratio.

Cake flour isn't just a very low-protein (gluten) version of all-purpose flour, it's actually made from a completely different species of wheat known as club wheat. The wheat is cracked, sifted and very finely milled to an almost talcum powder-like consistency, making it quite light by volume (about half an ounce less per cup than all-purpose flour).

Of course cake flour is usually quite heavily bleached. That obviously what's responsible for the whiteness of cake flour, though the bleaching also imparts some other very important characteristics. For one, it helps make the starch granules more absorbent (especially in very sugary batters), increasing their ability to form the gels that hold a cake layer up. Bleaching also helps fat molecules adhere more readily to starch granule surfaces, resulting in better fat distribution. The cumulative effect is lightness, sweetness, richness and tenderness...all the attributes one seeks in a good cake.

One side effect of the heavy bleaching that some people notice is a slightly acrid smell or sour taste. The reason for that is a trace amount of hydrochloric acid that the processing leaves behind.

Given what cake flour is made from and how it's treated, a concocted equivalent is by no means ideal. However you can approximate one cup of cake flour in the following way: start with one cup of all purpose flour, subtract two tablespoons, and replace them with corn starch (corn flour).

Bread flour is much like all-purpose flour, save for the fact that it's often made from just a single type of hard wheat (versus a blend). It's high in gluten, as you'd expect (usually around 13 percent) and because of that it produces the highest, fluffiest and chewiest breads. Oftentimes millers will add special "dough conditioners" to a bread flour to help maximize its loaf building potential: ascorbic acid or (increasingly rarely) potassium bromate, which helps oxidize the bonds on the ends of gluten molecules, helping them to form even longer, stretchier chains. Sometimes a little ground, malted barley (malt powder) is added. The malt introduces enzymes into the mix that speed the breakdown of starch into sugars, which feeds the yeast.

If you don't have access to bread flour at your local market, you can use a national brand all-purpose, which is going to have quite a bit of gluten anyway. "Spiking" it with a little vital wheat gluten (by adding about 1 teaspoon per 5-ounce cup of all-purpose flour) transforms it into a near exact replica.

For that matter, what's gluten? The next time you make a batch of bread or pizza dough, pinch off a little bit and work it between your fingers under the kitchen faucet for a minute. A good proportion of the dough, mostly water-soluble starch, will wash away. Yet a small rubbery ball will remain. That's it. The non-water-soluble, protein portion of flour: gluten.

Of course if you tried the same thing with just a pile of flour or a simple water-flour paste the whole thing would wash away. That's because gluten must be both watered and worked in order for it to organize itself into a mass.

What we call gluten is actually a combination of two different proteins: glutenin and gliadin. Both are extremely long-chain proteins, but with different properties. Glutenin molecules are rather fluid, and are capable of forming very strong bonds with one another. When they're worked they do just that, bonding both end-to-end and side-to-side into a kind of mesh or network. Gliadin molecules by comparison are tightly wound and bond weakly to one another and to glutenin molecules.

The elastic mesh that these molecules form is what allows dough to rise. The gluten mesh catches and holds carbon dioxide bubbles made by yeast, which would otherwise simply evaporate. The gas bubbles thus make small pockets in the dough. As the dough heats in the oven, those pockets begin to expand, partly as a result of heating gas, but mostly as a result of steam. The stretchy gluten mesh expands with the gas and steam until the starch in the dough gelatinizes, fixing the bubbles in place.

Just how big the bubbles get is determined by two things: the protein (gluten) content of the flour and the amount of water in the dough. More gluten provides more elasticity, allowing bubbles to expand, and more water makes a softer dough, allowing those bubbles to more easily combine with one another.

Of course the elasticity of gluten also makes breads chewy. Sometimes this is desirable (bagels and pizza crusts), sometimes it isn't (cakes and biscuits). Thus we have flours with different proportions of protein for different purposes.

So-called high-gluten flour has the highest protein content of any standard wheat flour (to 14 percent...only durum flour has more), and so has very few uses for most home bakers. So few, in fact, that it's not worth the time for most commercial flour makers to package and sell it in grocery stores. You either need to order it, or somehow con your local bakery or pizza parlor out of some.

White wheat flour is very similar to whole wheat flour, except that it's made from a blend of hard and soft white wheats as opposed the more common (at least in America) red wheats. It has almost identical characteristics to conventional whole wheat flour, save for the fact that it has a milder taste. The reason, because white wheat lacks the phenolic acids and tannins that are responsible for the vaguely bitter and/or astringent taste of red wheat. Increasingly popular among large-scale commercial bakeries, home bakers are using it more and more, especially those whose children and/or spouses are turned off by the flavor or color of whole wheat breads.

Here we have a far easier animal to classify, since whole wheat flour (called "whole meal" flour in other parts of the English-speaking world) is a 100% extraction flour, simply whole wheat berries ground to a fine powder. The types of wheat used in whole wheat flour may vary from mill to mill, but in general whole wheat is a very high protein flour, up around 12-15 percent. That protein figure is deceptive, however, since high protein is usually associated with an open, light crumb, and as we all know a 100% whole wheat loaf can be rather, well, dense.

The reason, because a significant amount of the protein in whole wheat flour isn't actually network-forming gluten from the endosperm, but rather a hodgepodge of miscellaneous proteins from other parts of the wheat berry. Other aspects of whole wheat flour also work to undermine a whole wheat dough's ability to rise. Notably, the jagged bits of bran it contains, which interfere with and/or slice to pieces the gluten networks that try to form. So in terms of performance, whole wheat flour should be considered a modest-to-low protein flour.

Whole wheat flour, because it contains the entire berry, contains more nutrients than white flour, especially in terms of vitamins, minerals, fat and fiber. It also has a much wheatier, more complex flavor. The main drawback of whole wheat flour is its storability. Because whole wheat includes the ground germ of the berry, it's about 2.5 percent fat. The fats it contains, for those of you who've followed previous posts on fat, are mostly unsaturated, which means they go rancid rather quickly — in as little as a month. Which means whole wheat flour is best stored in the freezer, where it will keep for up to a year.

Whole wheat flour comes ultra fine, fine, medium, coarse and stone ground.

Its other names are "family", "occident" or "plain" flour. It is by far the most common type of flour sold in stores, but at the same time, the hardest to define. Why is that? Because all-purpose flour is a blend of hard and soft wheats that almost every miller combines in different proportions. Part of the reason for that has to do with local availability. Harder wheats grow better in the plain states and softer ones grow better in southern states and the Pacific Northwest.

However different mills also have different ideas about what a good "all-purpose" flour is. "AP" flour is by definition a utility player in the kitchen, so it must be of at least passable use for everything from bread to cakes to brownies, as a thickening agent or a coating for fried foods. That's a tall task for a single product, so no wonder regional mills have historically tried to tailor their flours to meet the needs of their local markets. For example, in the North where people have historically eaten more yeast breads, higher protein (gluten) flours are favored, since more gluten gives bread a taller rise and a lighter crumb. In the South, where the biscuit is king, home bakers prefer a softer low-protein flour for a finer, more tender quick bread to eat with their country ham. Switch the two, and you've got trouble, buster.

Southern all-purpose flours can have a protein content as low as 7.5 percent. That's almost as low as the lowest protein cake flours. Try making a rustic bread with that! Big national brand AP flours (mostly made in northern locales) are quite high in protein, about 11.5 percent on average, which is very good for bread, since even commercial bread flours top out at around 13 percent protein. But think of that for a second: the jump from, say, King Arthur all-purpose flour to King Arthur bread flour is 1 percent protein. The variation between different brands of American all-purpose flours, however, can be as much as 5.5 percent. Amazing.

Of course, the amount of gluten isn't the only thing that makes these flours different from one another. As I wrote in the gluten post below, the character of gluten varies from one variety of wheat to another, opening up a whole different set of reasons for why recipes from one region often fail in another. Be aware that if you buy all-purpose flour from a local mill that's unbleached, it will have a shelf life of roughly eight months. After that the fat in the flour (and yes, flour has fat) will start to go rancid. Conventional bleached flour will keep for an almost unlimited period without turning, though it will eventually dry out (because yes, flour has water in it, too).

So let's pretend that you run a flour mill and you're making a pretty standard, 70-ish extraction white flour. If you were to grind it and bag it, you'd have what's known as "straight flour". Straight flour isn't commonly used in the US, though it is in places like France. Usually American mills process their flour it a bit more, by sifting it. Sift a bunch of straight flour and you get fine, so-called patent flour and the darker, coarser leftovers, so-called clear flour. Patent flours are divided into several grades according to their gluten (protein) content. From softest to hardest those grades are: Extra Short, First Patent, Second Patent, Medium Patent and Long Patent. Clear flour is divided into three grades according to coarseness: Fancy, First Clear and Second Clear. Fancy clear flour is actually quite fine, fine enough to be used in some types of pastry flour. First Clear is rather coarse, though it's often used by artisan bakers to create sturdy, rustic loaves. To give you a sense for just how coarse Second Clear flour is, it's most common use is as an animal feed.