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2023: Comparison Mill with stone millstones Vs Astrié Mill

Everything is often done so that you cannot compare the elements: telephone services, printing service... and it's often the same with mills. So let's think outside the box and learn to compare different mills with the same value scales.

If you only have 2 minutes to read, here's a summary:

  • an industrial roller mill makes a lot of flour very quickly. The grain is oxidized, permanently altering the nutritional values of your flour.

  • a traditional stone grinder allows the grain to be crushed slowly, guaranteeing a better quality of grinding and a more pronounced taste, but crushing breaks the starch bonds- gluten does not allow to offer a so-called local flour, sufficiently digestible and with high added value. It is necessary to make several passes to obtain the flour, which implies more handling and presence.

  • a mill with stone wheels known as Astrié allows the grain to be unrolled (no ironing and 80% extraction rate in one pass) in order to obtain the best flour quality at all levels (flour processing, softness, nutritional quality, etc.).

Comparator of professional flour mills | Astreia
Comparator of professional flour mills | Astreia

For this, it is essential to take a step back to gain height and already understand the raw material.



Action on wheat and therefore results on flour


Principle of this flour mill

Action on wheat

Be careful about adding value

Choose a manufacturer and not an assembler: how to see clearly?

Action on wheat

Why do we talk about exceptional flour?

How to choose your manufacturer?

Which grinder is best suited to my project?

As a reminder, what is a grain of wheat made of?

The grain of wheat is composed as follows:

  • the base of the grain of wheat: this is where there is the germ of the grain

  • in the middle the almond

  • outside the envelope (which surrounds the grain)

illustration Mill Astreia - the composition of wheat grain - Professional and agricultural Flour Mill

What does each part of the grain of wheat represent?

  • the germ of the grain represents between 2 to 3%

  • the almond represents about 78%

  • the grain envelope is about 20%

What is in each part of the grain of wheat?

  • the germ of the grain represents between 2 to 3%: contains all the vitamins and amino acids

  • the almond represents about 78%: hosts gluten and starch

  • the grain envelope represents about 20%: protein base of the grain is located on the reverse side of the envelope. This element is important for better bread rising and better breadmaking in general

Cylinder Mill

What is the principle?

The grain of wheat passes between cylinders to be crushed. The cylinders are more or less spaced apart. What emerges from this crushing (the milling products) is filtered. Then these milling products go back between two cylinders, are sifted, and so on up to 7 to 8 times depending on the cylinder mills. This is called a grind chart.

Action on the grain of wheat: what is the purpose of the operation?

We are going to peel the grain of wheat from the outside by going towards the heart of the grain of wheat closer and closer. The more we go to the heart of the grain of wheat, the more we trim the grain, the more we will have a white flour, but concentrated in gluten.

The germ is removed for two reasons:

  1. it gives a fattier consistency to the flour. If the flour is too oily, it must be consumed within 6 to 12 months whereas with a less oily flour the millers who make very large volumes of flour can keep it for several years without the flour going rancid.

  2. the germ is sold to the pharmaceutical industry to make a food supplement (irony of history, since we extract this germ which is therefore no longer present in the flour for the make consume in the form of food complement of a too impoverished flour!).

The famous "ash content" T80, T110....

Each time the millings are sieved, we will be able to separate the elements methodically: on one side the envelope (the bran), the germ and the kernel. So-called bran-typed flours are obtained. These are the famous "T": T80/T110/T130/T45.

We have a base of gluten and starch and depending on the "T" (ash content) there will be more or less "bran". Schematically.

The grain therefore passes through the rolling mills for the first time, we sieve it, in there we have the stung flour and the rest is iron, semolina... so we have to go back between the rolling mills, a times, twice, three times (...) until you get to the almond.

This cylinder mill therefore makes it possible to have flours that have more or less incorporated the envelope of the wheat grain (the bran). But never a germ.

So we are going to have more or less white flours:

  • very white flour: we are at the heart of the grain of wheat (T45), we are talking about oatmeal flour

  • rich flour: there is a lot of grain envelope (T150), we are at the very beginning of the almond, a so-called wholemeal flour

This system thus makes it possible to have very typical, very classified flours.

But which are only blends with more or less gluten or starch and more or less bran. But flours cannot reflect the entire grain of wheat.

In summary

The milling by cylinder allows very high yields (kilos of flour per hour) because they rotate at full speed. It is therefore not comparable with stone grinder mills.

The flours are very calibrated to meet a very standardized demand from the bakery and biscuit industry (food industry).

The flour is very heated and oxidized by dint of passing between the rolling mills and in addition the pneumatic transport of the flour adds oxidation to the basic process of the roller mill.

Flour is not nutritious and therefore obviously difficult to digest, because flour is only an assembly, therefore a concentrate of starch and gluten. If in addition the grain of wheat at the base is not of good quality, or even if the wheat has been modified to concentrate more gluten, it only worsens the process of concentrating gluten in the flour.

Gluten makes it possible to mechanize dough for the bakery as much as possible, so a high gluten concentration is expected by the baking industry, whatever the health consequences for the consumer and for the baker who handles it.

The germ, the bran (protein base) are removed so, inevitably, we have a gluten concentrate which is sometimes even corrected by adding even more gluten to promote industrial bread-making.

Classic traditional stone mill

Grindstone mill or Astrié mill? which one to choose ? Why ?
Illustration, all rights reserved Astreia

What is the principle of the Traditional Grinder Mill?

We have a "flying" stone wheel that crushes the grain of wheat due to its weight.

The best proof that it crushes the grain is that you have to put the "semolina" in the mill again to have flour and reach the 80% extraction rate.

You have to pass the grain of wheat several times between the millstones to extract 80% of the grain of wheat! Remember, the remaining 20% is the "sound" (the grain envelope).

What is the influence on the output of the mill: be careful!

It is often announced 30 kilos per hour. But be careful, is it 30 kilos of flour or wheat? Often puns are important.

A mill produces flour, not wheat! You must therefore know the yield expressed in KILOS OF FLOUR and not of wheat, it is nonsense.

Then, the extraction rate of 80% would allow us to imagine making 80 kilos of flour for 100 kilos of wheat. Except, remember, there's ironing here. So out of these supposed 80 kilos that come out of the mill, there are not 80 kilos of flour, but part of it must be put back into the mill to produce flour (and not semolina). This necessarily impacts the yield per hour since it has to be passed through the mill to produce flour. Sometimes doing this 2 or 3 times. Sometimes it is necessary to have someone available to do this or to have a traditional stone grinder that transports the material to put it back in the mill. With pneumatic transport of the material (does this remind you of anything?) .

In short, in terms of output: we end up with about 30 kilos of flour per hour maximum.

Influence on flour quality

The more the grain, semolina, or material passes back and forth between the millstones, the more it will be heated and oxidized, logically.

If the material is automatically brought back into the mill with pneumatic transport (as on a cylinder mill), then there is additional oxidation.


  1. On a traditional stone grinder, sieving is done by brushes which force the millings through the cloth. It is necessary to plan to change the canvas regularly.

  2. This passage in "force" makes the flour more pitted because the bran will be forced to pass between the meshes.

  3. Often a solution imagined by certain manufacturers (Tyrol for example) is to divide the bolting device into 3 parts. Thus, the whitest flour is found in the first third of the bolting, in the middle of the bolting the flour is more pitted and in the last third the flour is very pitted (more of its present therefore higher ash content).

This could make it possible to make a T80 at the beginning of the bolting, a T110 in the middle of the bolting and a T130 at the end of the bolting.

Note! Remember that the "ash level" system was invented for the operation of the roller mill which is not the example to follow in terms of nutrition or flour digestibility. So taking up this idea on a stone grinder mill would reveal to us that we are doing the same action on the grain of wheat, when the idea is really, on the contrary, not to carry out the same action!

Also remember, what we absolutely want is to keep the germ of the grain of wheat, but in this case of a sieve divided into 3 compartments, the germ will only be present in the first third of the sieve . In the whitest flour, not in the other flours which will therefore be of lower quality.

So if we divide our sieve into 3 parts, we force the millings through the mesh of the sieve with the brushes, we will have: a nutritious part with the germ in the first third and then a flour close to what you can have with a cylinder grind but... without the yield!

Influence on the dependency relationship with the manufacturer and the retailer

Here it will be necessary to make sure to have a good after-sales service for all the mechanism and electronic part and to make sure to provide in time for repairs of normal wear but to be taken into account in the budget.

Be careful too, because this type of mill is not often sold by the manufacturer but by a reseller or a company that assembles or has assembled different elements of your mill.

There is therefore a matchmaker and it is therefore strongly advised to check the terms and conditions of after-sales service and guarantees between the reseller and the actual manufacturer and its geographical location (in Europe? Abroad?). ..

Beware also of "manufacturers" who actually assemble certain parts of a mill and add others. Make sure who provides what (in terms of after-sales service) before your purchase and in what time frame the after-sales service can or cannot be provided. Beyond of course the fact that the assembly of all or part of the mill often raises the question of the consistency of the whole.

Stone Grinder Mill says Astriatum

What is the principle?

There are stone millstones there too, but the rotating millstone does not crush the grain by its weight but unrolls the grain.

Astreia mill - the composition of wheat grain - Professional and agricultural flour mill

How does scrolling change everything?

There is therefore no need to pass the grain several times between the millstones, since in a single pass we directly obtain the 80% extraction rate. So all of the wheat grain is present in the flour and the sieving allows the sound to be extracted (the envelope of the wheat grain which represents the remaining 20%).

It is this oscillating millstone (it is on a spring so as not to crush the grain) and the micrometric adjustment between the millstones that makes this mill an Astrié mill (named after their inventors Pierre and André Astrié).

These two elements combined and consistent with each other make it possible to overcome the weight of the grinding wheel and to adapt to the flow of grain that will arrive between the grinding wheels.

Influence on mill performance: all at once!

With an Astrié mill, the extraction rate is done in a single pass, so there is no need to re-run the semolina in the mill, no need for human intervention. The wheat grains pass through the mill and the flour comes out all at once, directly.

Influence on flour quality

Astrié flour is neither more nor less than the exact reflection of the grain.


On an Astrié mill, you have a sieve that is stored in the sieve (the wooden box that holds your flour). The sieving is carried out using taps which are not in contact with the flour but simply create a slight vibration which gently unclogs the flour through the sieve cloth.

So we don't come to change the quality of the flour according to the ash content that we want. We just change the sieve, and changing the sieve (the meshes are more or less tight) allows you to change the ash content without changing or modifying the quality of the flour!

A single burr mill for several flours
A single burr mill for several flours by simply changing the sieve

Influence on the autonomy of the peasant

With an Astrié mill, you enter into a process of using a LowTech product with few embedded technologies (if not none) and therefore great ease in understanding the consistency and operation of the product. end to end. Everything is visible, accessible to all. So you have a product in your hands that is made to last and that you can easily handle. The parts that compose it are simple, available everywhere and are easily changed. The sensors are mechanical, repairable.

Manufacturer and only Manufacturer: Astrié

Whichever Astrié mill manufacturer you choose, you are in direct contact with the craftsman who manufactures your mill "before your eyes". There are no Astrié mill resellers today, anywhere in the world.

This human link allows you to ensure the quality of the manufacturing, but also the follow-up and the after-sales service. Even if no one wants to think about it, it is imperative to know its limits, its availability, its reactivity and its possibilities before your purchase.

In addition, you will meet people who have real expertise in the field because the manufacturers of Astrié mills are generally farmers themselves, or even farmer bakers. This is the case at Astréia, since JM Ximena is both a farmer and a baker, so he has his own land, his bakery and he is perfectly capable of understanding your problems in the field to find reliable and consistent solutions. in time for you.


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