How to determine the direction of the fibers in the meat. At an angle: the secrets of a perfect cut of a steak

“Properly cutting meat is a real science,” the chef will say. And he will be absolutely right. After all, the method of cutting depends not only appearance dishes, but also taste qualities. We will tell you how to cut meat.

To begin with, the basic rule before work: the product must be fresh, the knife must be sharp, and the cutting board is moistened with water so that the blood does not soak into the wood.

When buying, please note:

• the meat should be elastic (do not leave dents when pressed)
• pink or red (old product is usually grey-brown with dark spots)
• not swollen and not wet (otherwise it was either injected with harmful injections or frozen several times)
• if the meat is fresh, then in this fresh not suitable for all dishes. For example, it should not be allowed to barbecue. For this dish, a piece should lie down for two to three days before cutting. During this time, excess blood will drain, and the muscle fibers that have contracted during slaughter will relax. Otherwise, the dish will just turn out tough.
• For barbecue, it is better to buy tenderloin, loin or ham. You can buy a product from other parts of the animal's body (lamb or pork), but in this case, you have to carefully cut the meat itself from the veins and bones.

How to cut meat: fillet

1. Allow the product to “rest” for at least 15 minutes before slicing. So its juices are evenly distributed throughout the piece of meat, and the shredding process itself will be easier.
2. Pay attention to the knife. In addition to its sharpness, it should also be with a smooth blade: no nicks and similarity to files. Otherwise, the cooked meat will look very unaesthetic.
3. Often housewives put themselves in front of a choice: cut the meat lengthwise or across? So here is the main rule: the product is cut only across the fibers. Otherwise, as a result of cooking, the dish will be hard, and the fibers will begin to get stuck between the teeth.
4. If we are talking about cutting the loin, then their size will depend on the dish itself, but the pieces should be the same - here's how to cut the meat across the fibers. For example, for barbecue, make them 3 by 3 cm or 5 by 5 cm.

How to cut meat into bones

1. For bone-in cuts, hold the end of the bone with a towel or kitchen towel while cutting. Cut the meat away from the bone into slices about 1 cm thick.
2. We cut cuts of the rib part. To do this, set the meat so that its ribs stick up vertically. If necessary, also hold it with a towel or kitchen napkin. Cut the product between the ribs into pieces of equal thickness. Another option is to completely remove the bones by removing them from the meat. This will cut the product into thin slices.

That's all! Enjoy your meal! After all, whatever adherents of vegetarianism say, a well-cooked meat product very tasty.

Any chef should know how to cut meat correctly and how to butcher meat fresh. The meat of any animal is an excellent, nutritious product, rich in beneficial acids and unique animal proteins. But to get delicious food, for each cooking method you need to be able to cut the meat correctly.
If you do not know how to cut meat, you can focus on the basic rules.

First: meat is cut only thawed, not frozen. After defrosting, or if the meat was just chilled, it should lie down for 15-20 minutes in the air. During this time, the juices will be distributed evenly over the tissues of the meat, the fibers will go limp.

Second: cut meat properly can only be done with a sharp long knife. No curly blades or old jagged knives. The best cutting board is made from real wood (you don't want to hurt yourself cutting meat on plastic or glass boards, do you?).

Third: cutting meat across the fibers is almost always necessary, only in rare exceptions - along. There is an opinion that if you cut meat across the fibers, juiciness is lost. But if it is properly processed thermally, then all the juices remain, and the meat turns out to be very tender, even as tough as beef.

In slicing, there are two fundamentally different methods that depend on the product: how to cut meat without bones and how to cut meat into bones. In the first case: you put a piece so that it is convenient to cut along the fibers, you orient the knife strictly horizontally at a right angle. You start cutting from a thick piece, observing a single thickness along the entire strip. You do not press too hard on the knife and at the same time you pull towards yourself, gradually cutting through, and not breaking through the product.

Properly cut meat on the bone you need a little differently. The knife is directed at an angle of 45 degrees, and the flesh is cut from the piece diagonally from the top to the very bone, which should lie on the cutting board (otherwise the piece of meat will slide, you will not be able to cut uniform pieces, and it will be very easy to injure yourself with a sharp knife ).

The specific method of slicing should depend on what dish is supposed to be cooked. If you have first and second courses in your plans, you can not really try to separate the bones from the pulp. Bones with a small amount of meat become the basis rich broth. Almost everyone knows how to cut meat for main courses. For frying, it is not recommended to make very thin pieces (if you cut it too thin, the meat will lose all the juices during cooking).

If the meat is not too soft and young, and without beating, feel free to cut across the fibers, so you will achieve softness and tenderness. For stewing, cutting into identical cubes is suitable.

For small snacks (canapes, light sandwiches with meat, etc.), the meat will again have to be cut across the fibers, since the snack should be easily chewed with any type of meat used, be it juicy chicken, tender pork or delicious beef. For rolls and stuffing, cutting only along the fibers is suitable. For real steaks and steaks, you need to cut the meat across the fibers and nothing else.

How to properly cut beef

The most difficult question for housewives is if not a ready-made store tenderloin falls into the hands, but a separate part from the carcass (for example, a whole leg, or a large piece of ribs).

Way, how to cut beef, is not too different from butchering all other types of meat. Having bought half a carcass or even a whole one, you need to properly distribute the meat for all dishes. Classic way how to cut beef involves dividing into such parts as shoulder, back, fillet, tenderloin, brisket, shank.

The back on the ribs is indispensable for roast beef, excellent dishes with minced meat and excellent cutlets will turn out from the shoulder blade. For steak or roast, take the loin, the tenderloin is suitable for any cooking method, but tastes good only with seasonings and sauce.

You can't do it without a brisket delicious soup, buy this meat without fail, although it is considered tough, sinewy and not too dietary. In terms of obtaining the necessary amino acids, proteins and useful substances in the soup, the brisket will become simply indispensable.

The shank is suitable only for cooking jellied meat and for long stewing, because it is tough meat, but there are valuable bones here, which, when cooked for a long time, will give the calcium necessary for a person. Do not try to buy only the pulp, because the bones and cartilage in beef are among the most valuable.

Markets and shops know how to properly butcher beef or any other meat so that not a single bone is left in the waste, but meat cut into pieces and individual bones is not always the best solution for homemade dishes.

How to properly cut pork

Pork is less dietary meat, but it is just as necessary for the body as beef. Many dishes taste much better when cooked with pork rather than beef or chicken. The best meat cut from a carcass is called tenderloin. It is soft, juicy, fatty, boneless meat. You can cook anything from it, except rich soup(it will be too oily and will have a bad effect on well-being, because it is very difficult for the liver, kidneys and the entire gastrointestinal tract).

The table shows the thermal conductivity values ​​of any type of wood, regardless of the type of wood, depending on the density at different volumetric moisture content.

Data are given at positive and negative temperatures along and across the fibers wood.

The thermal conductivity in the table is indicated for wood with a density (bulk weight) of 400 to 800 kg/m 3 . Thermal conductivity is given at the volumetric moisture content of wood in the range from 0 to 30%.

With an increase in the density and moisture content of wood, its thermal conductivity increases, both along and across the wood fibers. The value of thermal conductivity of wood is presented in the table in the range from minimum to maximum. Dimension of thermal conductivity. For example, at positive temperatures and a humidity of 20%, the maximum thermal conductivity of wood with a density of 400 kg / m 3 will be equal to 0.438 W / (m deg).

Thermal conductivity of wood across the fibers at different density and humidity

The values ​​of the thermal conductivity of wood are presented across the fibers at positive and negative temperatures and at different humidity.

The thermal conductivity in the table is given for wood with a bulk density (density) of 300 to 900 kg/m 3 .
The value of thermal conductivity is given at the volumetric moisture content of wood in the range from 0 (dry wood) to 30%.

The thermal conductivity of wood in the table shows the minimum, average and maximum for any wood across the fibers, depending on the density. Dimension of thermal conductivity.

Density of a tree at a temperature of 20 °C

Given table of density of wood of various species at a temperature of 20 ° C. The density of the tree in the table is given in the dimension of 10 3 kg / m 3, that is, in tons per cubic meter.

The density of the following species is indicated: dry wood, satin, cork, balsa, bamboo, beech, birch, cherry, hickory, pear, oak, Canadian spruce, iron (backout), willow, gum, cedar, dogwood, maple, red (Honduras , Spain), linden, larch, juniper, alder, walnut, aspen, holly, fir, plane tree, carob, boxwood, sandalwood, plum, pine (white, common), teak (Indian, African), poplar, ebony (black ), elm, apple tree, ash.

The density of dry wood in the table is indicated in a certain range, it depends on the species and the place of felling. For example, the density of pine has a range of 370 to 600 kg/m 3 ; oak density is 600 ... 900 kg / m 3; spruce density 480-700 kg / m 3; birch density 510 ... 770 kg / m 3. It should be noted that the density of coniferous wood has a value correlated with hardwood.

It can be seen from the table that, under normal conditions, the cork tree has the lowest density(balsa), the density of which is 110 ... 140 kg / m 3, and the tree with the highest density is ironwood(bakout) and ebony (black). The density of this tree is 1110 ... 1330 kg / m 3, which is even more.

Sources:
1. .
2. Franchuk A.U. Tables of thermal performance of building materials, M .: Research Institute of Building Physics, 1969 - 142 p.
3. Physical quantities. Directory. A.P. Babichev, N.A. Babushkina, A.M. Bratkovsky and others; Ed. I.S. Grigorieva, E.Z. Meilikhov. - M.: Energoatomizdat, 1991. - 1232 p.

Strength is the ability of wood to resist destruction under the influence of mechanical loads. The strength of wood depends on the direction of the acting load, wood species, density, humidity, and the presence of defects. It is characterized by tensile strength - the stress at which the sample is destroyed.

Only the bound moisture contained in the cell membranes has a significant effect on the strength of wood. With an increase in bound moisture, the strength of wood decreases (especially at a moisture content of 20 ... 25%). A further increase in humidity beyond the limit of hygroscopicity (30%) does not affect the strength of wood. The tensile strength values ​​can only be compared at the same moisture content of the wood.

In addition to moisture, the mechanical properties of wood are also affected by the duration of the load. Therefore, when testing wood, it adheres to a given loading rate for each type of test.

There are main types of action of forces: tension, compression, bending, shearing.

Tensile strength. The average tensile strength along the fibers (GOST 16483.23--73) for all rocks is 130 MPa. The tensile strength along the fibers is greatly influenced by the structure of the wood. Even a slight deviation from the correct arrangement of the fibers causes a decrease in strength.

The tensile strength of wood across the fibers (GOST 16483.28--73) is very low and, on average, is 1/2 of the tensile strength along the fibers, i.e. 6.5 MPa. Therefore, wood is almost never used in parts that work in tension across the fibers. The strength of wood across the fibers is important in the development of cutting modes and wood drying modes.

Ultimate compressive strength (GOST 16483.10--73). Distinguish between compression along and across the fibers. When compressed along the fibers, the deformation is expressed in a slight shortening of the sample. Compressive failure begins with buckling of individual fibers; in wet samples and samples from soft and viscous rocks, it manifests itself as a collapse of the ends and buckling of the sides, and in dry samples and in hard wood it causes a shift of one part of the sample relative to the other.

The compressive strength of wood across the fibers is about eight times lower than along the fibers. When compressing across the fibers, it is not always possible to accurately determine the moment of destruction of wood and determine the magnitude of the destructive load.

The wood is tested for compression across the fibers in the radial and tangential directions. In hardwoods with wide core beams (oak, beech, hornbeam), the strength in radial compression is one and a half times higher than in tangential; in conifers, on the contrary, the strength is higher with tangential compression.

Ultimate strength in static bending (GOST 16483.3--84). During bending, especially under concentrated loads, the upper layers of wood experience compressive stresses, and the lower layers experience tension along the fibers. Approximately in the middle of the height of the element, there is a plane in which there is neither compressive nor tensile stress. This plane is called neutral; the maximum tangential stresses occur in it. The ultimate strength in compression is less than in tension, so failure begins in the compressed zone. Visible destruction begins in the stretched zone and is expressed in the rupture of the outermost fibers.

The tensile strength of wood depends on the species and humidity. Flexural strength is twice the compressive strength along the fibers.

Shear strength of wood. External forces that cause the movement of one part of the part relative to another are called shear. There are three cases of shear: shearing along the fibers, across the fibers and cutting.

The shear strength along the fibers is 1/5 of the compressive strength along the fibers. In hardwoods with wide core rays (beech, oak, hornbeam), chipping along the tangential plane is 10 ... 30% higher than along the radial one.

The shear strength across the fibers is approximately two times less than the shear strength along the fibers. The strength of wood when cut across the fibers is four times higher than the strength when shearing along the fibers.

According to the degree of hardness of the end surface, all tree species at 12% moisture can be divided into three groups: soft (end hardness 40 N / mm2 or less) - pine, spruce, cedar, fir, poplar, linden, aspen, alder; hard (end hardness from 40 to 80 N / mm2) - Siberian larch, birch, beech, elm, elm, elm, maple, apple tree, ash; very hard (end hardness more than 80 N / mm2) - white locust, iron birch, hornbeam, dogwood, boxwood, yew, etc.

The hardness of wood is essential when processing it with cutting tools: milling, sawing, peeling, and also in those cases when it is subjected to abrasion when constructing floors, stairs, railings.

The ability of wood to hold metal fasteners. When driving a nail into the wood perpendicular to the fibers, they are partially cut, partially bent; the fibers of the wood move apart and exert pressure on the side of the nail, which causes friction to hold the nail in the wood. When testing wood, the force in newtons or the specific force in megapascals is determined, which is necessary to pull out a nail or screw of given dimensions.

In places of cuts or joints of wooden parts with metal (under shoes, bolts, etc.), the compressive strength of wood across the fibers is of significant practical importance. A classic example of the work of wood in compression across the fibers are also railway sleepers (places under the rails). There are three cases of wood compression across the fibers: 1. The load is distributed over the entire surface of the compressible part.

2. The load is applied to part of the length, but across the entire width of the part. 3. The load is applied to parts of the length and width of the part (Fig. 54). All these cases are encountered in practice: the first case - when pressing wood, the second - when using sleepers under the rails, the third - when using wood under the heads of metal fasteners. When compressed across the fibers of wood of different species, two types of deformation are observed: single-phase, as in compression along the fibers, and three-phase, characterized by a more complex diagram (see Fig. 54).

Table 35. Compressive strength of wood along the fibers.

Rice. 54. Cases of compression across the fibers (below) and diagrams of compression of wood across the fibers (above): a - with three-phase; b - with single-phase deformation; 1 - compression over the entire surface; 2 - compression into parts of the length; 3 - compression into parts of length and width.

With single-phase deformation, the diagram shows a well-defined approximately straight section, which continues almost until the maximum load is reached, at which the wood sample is destroyed. With three-phase deformation, the process of deformation of wood during compression across the fibers passes through three phases: the first phase is characterized in the diagram by an initial, approximately rectilinear section, showing that at this stage of deformation, wood conditionally obeys Hooke's law, as in single-phase deformation; at the end of this phase, the conditional limit of proportionality is reached; the second phase is characterized in the diagram by an almost horizontal or slightly inclined curvilinear section; the transition from the first phase to the second is more or less abrupt; the third phase is characterized in the diagram by a straight section with a steep slope; the transition from the second phase to the third is in most cases gradual.

According to the nature of deformation under radial and tangential compression, the rocks can be divided into two groups: the first group includes coniferous and ring-vascular hardwoods (with the exception of oak), and the second group includes scattered-vascular hardwoods. The wood of coniferous species (pine, spruce) and annular deciduous species (ash, elm) under radial compression gives a diagram characteristic of three-phase deformation, and under tangential compression - a diagram of single-phase deformation.

The noted nature of the deformation of the wood of these species can be explained as follows. During radial compression, the deformation of the first phase proceeds mainly due to the compression of the early zone of annual layers, which is mechanically weak; the first phase continues until the walls of the elements of the early zone lose their stability and begin to collapse. With the loss of stability of these elements, the second phase begins, when the deformation proceeds mainly as a result of the collapse of the elements of the early zone; this occurs at a nearly constant or slightly increasing load. As the elements of the late zone of the annual layers are involved in the deformation, the second phase smoothly passes into the third. The third phase proceeds mainly due to the compression of the elements of the late zone, which consists mainly of mechanical fibers, which can only be crushed under heavy loads.

Under tangential compression, deformation occurs from the very beginning due to the elements of both zones of the annual layer, and the nature of the deformation is naturally determined by the elements of the late zone. At the end of deformation, the destruction of the sample occurs, which is more clearly expressed in coniferous wood: the samples usually bulge towards the convexity of the annual layers, which, when tangentially bent, behave like crooked beams during longitudinal bending.

Among ring-vascular hardwoods, oak does not follow the above patterns, the wood of which, under radial compression, deforms according to a single-phase type, and under tangential compression it shows a tendency to switch to three-phase deformation. This is explained by the fact that under radial compression, the nature of deformation is strongly influenced by wide core rays. With tangential compression, the tendency to transition to three-phase deformation is explained by the radial grouping of small vessels in the late zone.

The wood of scattered vascular hardwoods (birch, aspen, beech) showed three-phase deformation under both radial and tangential compression, which, apparently, should be explained by the absence of a noticeable difference between the early and late zones of annual layers. Hornbeam wood has a transitional form of deformation (from three-phase to single-phase); Obviously, in this case, the influence of falsely wide core rays comes into play.

The beginning of the destruction of wood can be observed only with single-phase deformation; with three-phase deformation, wood can be compacted up to a quarter of the initial height without visible signs of destruction. For this reason, when testing for compression across the fibers, they are limited to determining the stress at the limit of proportionality from the compression diagram, without bringing the sample to failure.

Wood is tested in two ways: under compression over the entire surface of the sample and under compression over part of the length, but over the entire width (collapse). For compression tests across the fibers, a sample is made of the same shape and dimensions as in compression along the fibers; the annual layers at the ends in this sample should be parallel to one pair of opposite faces and perpendicular to the other pair. The sample is placed on the support of the machine by the side surface and is subjected to a stepped load over the entire upper surface at an average speed of 100 ± 20 kg/min. The deformation of soft wood is measured with an indicator with an accuracy of 0.005 mm every 20 kg of load and hard wood - every 40 kg; the test continues until a clear transition of the proportionality limit. On the basis of paired readings (load-strain), a compression diagram is drawn, on which the load is determined with an accuracy of 5 kg at the proportionality limit as the ordinate of the transition point of the rectilinear section of the diagram into a clearly curvilinear one. The conditional compressive strength across the fibers is calculated by dividing the load found by the specified method at the limit of proportionality by the compression area (the product of the width of the sample by its length).

For crushing tests, a sample in the form of a block of square section 20X20 mm, 60 mm long is used. The load on such a sample is transmitted across the entire width through a steel prism 2 cm wide, placed in the middle of the sample perpendicular to the length; the edges of the prism adjacent to the sample are rounded with a radius of 2 mm. Otherwise, the procedure and test conditions are the same as in the first method, but the conditional tensile strength is calculated by dividing the load at the limit of proportionality by the compression area equal to 1.8 a, where a is the width of the sample, 1.8 is the average width of the pressure surface prisms in centimeters.

The conditional tensile strength in crushing across the fibers is 20-25% higher than in compression; this is due to the additional resistance from fiber bending at the edges of the prism. In the third case of compression across the fibers (see Fig. 54), the indicators of the conditional tensile strength are slightly higher than those obtained in the second case as a result of additional resistance to chipping across the fibers at the edges of the stamp running parallel to the wood fibers.

Table 36

Wood species with wide or very numerous beams (oak, beech, maple, partly birch) is characterized by a higher conditional tensile strength in radial crushing (about 1.5 times); for other hardwoods (with narrow beams), the indicators of the conditional crushing strength in both directions are almost the same or differ little.

For coniferous wood, on the contrary, the conditional tensile strength with tangential crushing is 1.5 times higher than with radial crushing due to a sharp heterogeneity in the structure of annual layers; in case of radial crushing, it is mainly the weaker, early wood that is deformed, and in case of tangential compression, the load from the very beginning is also perceived by late wood. Compared to the compressive strength along the grain, the conventional crush strength across the fibers averages about 1/8 (from 1/6 for hard hardwoods to 1/10 for softwoods and soft hardwoods).