Modern technology has made possible great progess in the preparation of food, yet the old methods of the preparation of food on an open fire e. g. barbecue are still popular, in some cases they are even considered to be better than the more recent techniques because they give the food a specific taste.

For this purpose various sorts of aromatic wood such as apple, oak, cherry, peach wood etc. have been used as fuel. Yet the use of wood as fuel has certain disadvantages, because the wood burns with a flame and a longer period of time is required for the flame to subside and a layer of hot embers to form. The aromatic volatile substances mostly evaporate too fast from the wood so that the food is not aromatized.

Due to these disadvantages people have gradually gone over to baking with charcoal which burns with a flame only for a short time so that the baking is easy to supervise.

The main disadvantage of charcoal is that it does not contain any moisture, which makes the food dry at baking; besides, it does not contain any aromatic volatile substances that would aromatize the food.

Known are also charcoal briquettes, yet it is characteristic of them that they do not contain any moisture, which makes the food dry at baking, and in their manufacture adhesives on tar basis are used, which are harmful for health.

Ordinary wooden briquettes burn with a flame and when the flame goes out, they disintegrate.

For baking on a barbecue also wooden pellets are used, but since they burn fast, they are used only as an additive to charcoal.

The subject of the present invention are aromatic wooden briquettes made of a mixture of various sorts of wood and various sorts of aromatic plants or aromatic parts of plants, which contain from 5-30 % of natural moisture, preferably 10-20 % of moisture. Wooden briquettes according to the invention serve as a fuel at which or above which the food is prepared, e. g. different kinds of food like meat and preparations from flour like bread, bread products, pizzas etc. are baked, whereat, due to the moisture present in the briquettes, the food is not dried up and remains juicy and at the same time gains a specific flavour.

The briquettes according to the invention make it possible that with a proper choice of briquettes i. e. of a combination of various sorts of wood and various sorts of aromatic plants, in the preparation or baking of food a specific kind of aroma, which suits it best, is chosen for a specific kind of food.

A preferred mixture of various sorts of wood for the manufacturing the aromatic wooden briquettes according to the invention is a mixture of beech wood, vine wood and olive wood. The most preferred mixture of various sorts of wood for the manufacturing the aromatic wooden briquettes is a mixture of vine wood and olive wood.

As aromatic plants and parts thereof, which are added to the mixture of various sorts of wood, any aromatic plants may be used, preferably rosemary (rosemary needles), juniper (juniper needles), laurel (laurel leaf), oregano, garlic and caraway. To the mixture of various sorts of wood the aromatic parts of a particular aromatic plant or a combination of aromatic parts of various sorts of aromatic plants are added.

The briquettes according to the invention are made in such a manner that suitable proportions of various sorts of wood and of aromatic parts of plants are used, the particle size of the wood mixture is suitably distributed, and a sufficiently high pressure for the compression of the wood mixture is applied.

As vine wood and olive wood there is primarily used waste wood i. e. the biomass resulting from the annual pruning of vines and olives. Thus, the invention also solves the problem of the removal of the biomass resulting from the pruning of vines and olives, which is considered waste and is usually discarded or burned.

As beech wood the waste beech sawdust in the form of polishing dust resulting from the finishing of products made from beech wood is used.

The waste biomass is first coarsely milled to a bulk density of about 300 kg/m3. Then various sorts of wood and aromatic parts of one or more sorts of aromatic plants are additionaly milled and mixed in an appropriate mill in order to obtain a mixture with the following composition: 5-60 % of beech wood in the form of polishing dust, 5-40 % of vine wood, 5-40 % of olive wood and 1-10 % of aromatic parts of plants.

A mixture can be made also of only two sorts of waste biomass i. e. of the biomass of vine and olives. The waste biomass of vine and olives is first coarsely milled to a bulk density of about 300 kg/m3. Then these two sorts of wood and aromatic plants or aromatic parts of plants are additionaly milled and mixed in an appropirate mill in order to obtain a mixture with the following composition: 70-95 % of vine wood, 5-10 % of olive wood and 1-3 % of aromatic parts of plants.

Preferably, rosemary or oregano are used as aromatic plants.

By milling, a mixture with an appropriate composition of sieving proportions is obtained: 10-30 % of particles with a particle size of 0-0. 3 mm, 20-50 % of particles with a particle size of 0.3-0. 8 mm and 20-40 % of particles with aparticle size of 0.8-1. 2 mm.

Different sorts of wood have a different degree of moisture. For example, beech polishing dust has a moisture of about 8 %, whereas the wood biomass of vines and olives has a moisture content of 50-55 %.

In order to achieve an optimal moisture of the wood mass, the obtained mixture i. e. the milled mass is filled into a provisional silo where the moisture among the single sorts of wood is equalized at a temperature of 5°C-90°C, preferably at a temperature of about 20°C, to an absolute moisture content of 5-30 %, preferably 10-20 %, still more preferably 14-15%. Subsequently, this mixture is filled into a briquette press.

In a specially designed briquette press the wood mass is, at a pressure of 1500-2000 bars, 10-20 times pressed into individual briquettes. The moisture present in the wood mass acts as a binder.

The specific composition of the wood mixture, particularly the low granulation of the wood mixture and the high pressure used give to the wooden briquettes according to the invention specific properties. As a consequence of the high pressure the surface of the briquettes manufactured according to the present invention is smooth. The smooth surface of the briquettes prevents them from disintegrating at burning. At burning the briquettes according to the invention no single burning parts twist and separate from the briquette mass as it is the case with wooden pellets, therefore the briquettes do not disintegrate at burning but retain the original form. Such briquettes burn with a flame only for a short time, whereupon they are surrounded by a layer of ashes, under which the wood mass slowly glows and gives off moisture and aromatic volatile substances.

Such briquettes make possible a uniform baking without the use of charcoal and are particularly suitable for barbecuing since they aromatize the food and give it a specific and pleasant taste. The briquettes according to the invention may also be used for smoking different kinds of food at lower temperatures if the food is lifted high enough above the glowing briquettes.

The following examples explain but in no way limit the present invention.

Examples Example 1 In an appropriate mill a) there are mixed and milled together: - waste beech wood in the form of polishing dust, - waste vine wood and olive wood, which were previously coarsely milled to a bulk density of about 300 kg/m3, - aromatic parts of one or more aromatic plants in the following proportion: 60 % of beech wood in the form of polishing dust, 19 % of vine wood, 20 % of olive wood, 1 % of aromatic parts of plants (rosemary needles), so that a mixture with the following composition of sieving proportions is obtained: 10-30 % of particles with a particle size of 0-0. 3 mm, 20-50 % of particles with a particle size of 0.3-0. 8 mm and 20-40 % of particles with a particle size of 0.8-1. 2 mm; ) the obtained mixture is filled into a provisional silo, wherein the moisture among the single sorts of wood is equalized at a temperature of about 20°C to the absolute moisture content of 14-15 % ; ) the. mixture is filled into a briquette press, wherein at a pressure 1500-2000 bars it is compressed into individual briquettes with the present moisture acting as a binder. i such a manner briquettes are manufactured which burn with a flame only for a hort time, whereupon they are surrounded by a layer of ashes and glow further without flame.

, xample 2 ri an appropriate mill there are mixed and milled together: waste vine wood, which was previously coarsely milled to a bulk density of about 300 kg/m3, - waste olive wood, which was previously coarsely milled to a bulk density of about 300 kg/m3, aromatic parts of one or more aromatic plants in the following proportion: 90 % of vine wood, 8 % of olive wood, 2 % of aromatic parts of plants (rosemary needles), so that a mixture with the following composition of sieving proportions is obtained: 10-30 % of particles with a particle size of 0-0. 3 mm, 20-50 % of particles with a particle size of 0.3-0. 8 mm and 20-40 % of particles with a particle size of 0.8-1. 2 mm; b) the obtained mixture is filled into a provisional silo, wherein the moisture between the single sorts of wood is equalized at a temperature of about 20°C to the absolute moisture content of 14-15 %; c) the mixture is filled into a briquette press, wherein at a pressure 1500-2000 bars it is compressed into individual briquettes with the present moisture acting as a binder.

In such a manner briquettes are manufactured which burn with a flame only for a short time, whereupon they are surrounded by a layer of ashes and glow further without flame.