From: sbhattac@rnd.GBA.NYU.EDU (Shankar Bhattacharyya)
Newsgroups: rec.food.cooking
Subject: Re: Semolina Flour and graininess of pasta
Date: 22 Nov 92 12:29:36 GMT
Organization: NYU Stern School of Business

In article <memo.760698@cix.compulink.co.uk> maryb@cix.compulink.co.uk writes:

>In-Reply-To: <32892@rnd.GBA.NYU.EDU> sbhattac@rnd.GBA.NYU.EDU (Shankar Bhattacharyya)

>When I buy fresh pasta, it usually says egg pasta and it's usually 
>yummy. Is this because it's fresh? Are the eggs disguising some awful 
>wheat base? Confused!

It's good because someone who knew what's what made it, and cared about
ingredients, and about doing it right. There is perfectly good pasta with
eggs, and perfectly good pasta without eggs.

If you have sufficiently good cereal stock, you can make good pasta without
any eggs. If you don't have good stock, you may need eggs, or some other
texture enhancing agent. But that is a long cry from the converse claim,
that pasta containing egg must therefore be inferior. They are simply
different things.

Anyway ...

Having commented briefly on semolina and pasta in the last few days, I
have received requests for clarification, and the thread lives on, so I'm
going to indulge in a meta-post. This is easier than writing a set of more
limited, distinct responses. Pardon the duplication of stuff that has gone
before. I'm going to run on for quite a bit.

Allow me to repeat that I don't make pasta, and what I know about pasta,
flour, and semolina is mostly about what is in them, not about how you make
pasta from semolina or flour. I know a completely unreasonable amount
about how to measure all this stuff, and damn all about what you do with
all that sort of information. And I am not even a fussy consumer of pasta.

I can pretty much promise that your pasta will not get any better because
of this post.

May I encourage those who do know about making pasta to provide some
information more useful than this? I don't want to hijack this thread
entirely, particularly since you can make perfectly good pasta at home
without knowing all of this. It would be a pity if the poor cook who wanted
to know how to make decent pasta just got a long and completely useless
account of principles.

My practical advice is limited to the following:

If you want to make pasta without eggs, use a hard wheat semolina, like a
durum. Knead enough to let the gluten develop the appropriate elasticity.
If you do not knead enough the pasta will fall apart. If you knead too long
you have other problems, but I don't recall what those are.

If you want to use eggs you are no longer limited to straight semolina.
You can use at least some flour, and I don't know any more than that.
Perhaps you can use a lot of flour. You still want a durum wheat, though.

That advice, of course, is so general as to be relatively useless. All I'm
saying is that what you need to make good pasta is advice, from someone who
makes pasta, on how to interpret "knead enough", and "appropriate
elasticity". You don't need the nerdy stuff that occupies the rest of this
post. But since people seem interested, what the hell, I'll launch into an
account of the principles. Just keep in mind that the principles are of
limited use in the kitchen. Sergei Bubka probably manages the pole vault
just fine without any detailed understanding of gravitation, general
relativity, and elasticity of materials.

All pasta is made by forcing a dough into a specific shape. Flat pastas are
rolled, other shapes are extruded. Some Asian pasta products are shaped by
repeatedly stretching the dough; looks very nifty. Anyway, almost without
exception, these shapes are such that one dimension, and often two, is
quite small. This makes pasta quite fragile.

For pasta to hold together, therefore, the dough needs to have certain
characteristics as to tensile strength and such. The same effects, by and
large, determine the texture of the final cooked product.

There are two ways to attend to this.

The first is to use a base material which naturally provides high strength.
That is where a hard wheat semolina comes in.

The second is to use some added ingredient which provides strength. That
is where egg comes in. Other texturizers, too.

Pasta made without eggs is called macaroni. Pasta made with eggs is called
egg noodles, usually just noodles. There are, of course, names based on
shapes, but they are all either macaroni or noodles. Commercial elbows and
linguini are macaronis. Wider ribbons are almost always noodles. And so on.

In order to be called a noodle the pasta must contain 5.5% egg solids
(whole egg or yolk or combinations thereof). That is the law in the US, and
the law is enforced. If you add eggs, but not as much as 5.5% on a dry
basis, you wind up having to call the product a "pasta product" or a "pasta
and egg product" instead of a noodle. Manufacturers don't like to do that.
Eggs are expensive. If they add eggs they want to be able to name their
product accordingly. People do sometimes make such products deliberately.
Usually that is for packaged soups and such.

Noodles can be made with semolina, or with various amounts of flour blended
in. Perhaps even with all flour, but I don't know about that. My technical
involvement with pasta is limited entirely to analysis, so I will repeat
that I don't know anything practical about how to make it.

I see no reason to suppose that noodles are inferior just because the egg
allows the maker to use flour in the mix. Noodles are noodles, and
macaroni is macaroni. I know Italians who don't regard them as even closely
related. Hell, some of them use red sauces only with one of these things,
though I forget which. I have no opinion on that subject.

Macaroni, nominally, is made with just semolina, possibly some flour, and
water. Ideally it gets made with just a hard wheat semolina and water.
Since there is no egg to help the texture along, the semolina must provide
what is necessary to maintain the texture. That strength comes from the
gluten.

Different wheats have different levels of gluten. Hard wheats like durum
have high gluten content. But that is not all. All glutens are not created
equal. There are large qualitative differences between different glutens.
The pasta industry tests their cereal stock for gluten quality. I'll get
back to that in a bit.

Durum has gluten of high quality. "Quality" pretty much means "elasticity"
in this context, though there are issues related to how much water gets
held by the protein backbone, and so on.

The quality of the gluten varies depending on the strain of the wheat,
where it was grown, what soil and climatic conditions prevailed, and so on.
As to exactly what it is about the gluten that makes it good, or not good,
I don't know. It is obviously related to the structure of the protein, but
that says only the obvious. I have no non-obvious thoughts on the subject,
except to remind people that proteins, even proteins with the same name
(gluten, for instance), cover a considerable range.

Standard cereal technology reference books have information about different
types of wheat, but I suspect that even that is more information than is
useful to the non-industrial cook. For even more finely discriminated data,
the Department of Agriculture puts out an annual crop report when the
harvest is in. It's called the Wheat Quality Report, or something like
that. We get those at work, but I don't pay any attention to them.
Manufacturers do. They adjust their processes in small ways to compensate.
I don't have the faintest notion what these adjustments are.

If you want to use inferior cereal stock you wind up adding something to
improve the texture. This is often done for cheap macaroni. One solution
is to add industrial texture enhancing agents. A common one is glyceryl
monostearate.  Eastman Chemical offers it as a product which "improves the
texture experience". I have a brochure from them which uses those words, or
words very close indeed. It's been a while since I looked at it.

US law also allows manufacturers to add a small amount of egg white to
macaroni, so it is not exactly correct to say that macaroni is made without
eggs. That is a good default definition, but we do need to remember that a
small amount of egg white is permitted. However, no yolk is allowed.

Still, good macaroni does not contain egg white. Manufacturers like to be
able to say, "Made with 100% durum semolina and water." I am relatively
comfortable with the idea that macaroni with egg white is inferior to
macaroni with it as an indredient. That may simply be the manifestation of
a purist streak.

I would still resist questions as to whether noodles are therefore
inferior to macaroni. I regard them as simply different.

A comment on what the egg (yolk, whole, or white) is supposed to do: It is
tempting to think that the purpose is to raise the protein. That is not the
case. After all, adding some casein would not work. The nature of the
protein matters. I would make the reasonably informed speculation that what
is important about eggs is that egg proteins cross-link when they are
heated, and provide a rather strongly structured matrix. This provides
strength. A very large number of foods use this characteristic of egg
proteins. Meringues rely on this property in egg whites. Hollandaise and
Bearnaise sauces rely on this property in yolk. Quiche, souffles,
custards, omelettes, and scrambled eggs rely on the crosslinking of both
components of egg proteins.

I don't know if you can just add gluten to weak semolina or pasta and
improve its behaviour. It sounds plausible, but I don't know.

As to gluten quality and measurement thereof:  I did that once or twice,
years ago, basically so I would know, at least in principle, how it was
done. You need current experience to do this, and I am quite sure that I
would mess it up the first few times, were I to try it today. I messed it
up back then, too.

The procedure is basically fairly simple. You take a specific weight of the
semolina, add a specified amount of water at a specified temperature, allow
to stand for a specified period, and then proceed to work the mess till you
have a rather wet dough. Then you continue to work it in a gentle stream
of water (people just hold it under a tap as they work it), until the
starch is washed out. What remains in your hands is mostly gluten. You then
stretch the gluten between your hands, until it breaks. The better the
gluten, the more it will stretch before it snaps. Depending on how far it
stretches, the gluten quality gets described as poor, fair, good, or
excellent. The standard methods of analysis prescribed by the AACC
(American Association of Cereal Chemists), specifies how far the gluten
must stretch to qualify for each of these classifications. For marginal
cases you also make judgments based on how it feels in your hands. Since
this does involve judgment, and handling technique matters, you really need
to be shown this hands on, and you need to be in practice. It isn't exactly
a measurement. But it is a standard procedure.

You also measure the water content of the final gluten, and do something or
other with that number. Darned if I remember what.

Anyway, for most people making pasta at home, this is of little use.
Manufacturers specify that what they buy must meet certain specifications,
and they require a certificate of analysis. They specify a maximum maltase
level, mineral content, colour, moisture, protein, so on and so forth.

But the home user cannot exactly go to the supermarket and say, "I want
semolina, of the following strain, of the following particle size
distribution, and of gluten quality good or excellent based on AACC method
number such and such." We have to live with what we get.

I suggest that people should stop worrying too much about this sort of
detail. Go buy a durum semolina. Make some pasta. Eat it. And stop worrying
about stuff that you cannot control. It's not that important.

A whole bunch of measurements get made on pasta to monitor the physical
properties. The tensile strength when cooked (mostly for spaghetti, done
in a fancy-priced instrument which holds the strand between a pair of
collets, and stretches the strand till it snaps), the droop of a cooked
strand, so on and so forth. Most of these I have never seen done.

I have also been asked what the difference is between flour and semolina,
particle size apart. There is a good deal of difference, and I will try and
address that briefly, and cautiously, since I'm no expert.

A kernel of wheat is not a homogeneous object. There is the germ, the
endosperm and so on. Different portions of the kernel fracture in different
ways. So, if you put wheat through a mill, and remove particles based on
size, depending on where and when you collect stuff, the material you
collect comes disproportionately from different sections of the kernel.
Semolina comes mostly from the endosperm. So it is not just a coarsely
ground kernel of wheat. It is a coarsely ground *subsection* of a kernel
of wheat. That statement is a bit stronger than one can justify, but not
by a whole lot.

When the cereal industry asks, "How much flour does this semolina contain?"
they really just mean fines. But that is in a very restricted context. In
any other context "flour" is a more inclusive term. Basically, it refers
to a fine grind that includes most, sometimes all, of the kernel. So there
is more difference than just the particle size. Semolina comes from a
specific section of the kernel. Flour is more general.

I have now unburdened myself of almost everything I know about semolina,
flour, and pasta. If some things are not clear, there are good reasons. I
only kind of know the non-analytical stuff.

And, having stayed with me to this point, if you are miffed that you still
don't know what to do about making better pasta, hey, I warned you up
front.

- Shankar