FR2509747A1 - Smoke flavoured malt prodn. - by heating malt with smoke from burning peat in controlled temp. sequence - Google Patents

Abstract

Prodn. of smoke-flavoured malt (whisky malt) comprises first heating for 4 hr with air at 48 deg.C., the air being loaded with smoke by passing under grills being used to dry peat of 40% moisture content, then passing through green malt spread out on perforated plates, 80% of this air is evacuated through a chimney. The temp. is then increased to 80 deg.C. for 1 hr to cause partial caramelisation and fixation of flavour components, 80% of the air used is also evacuated. A flow of air at 60 deg.C. is maintained for 6 hr with a weaker supply of smoke made by slow combustion of peat of 30% moisture content, placed above a burner. 80% of this air is evacuated. Then the temp. is quickly increased to 90 deg.C. for 3 hr with vigorous release of smoke by total combustion of the peat. During this stage all the air is recirculated.

Description

 The present invention relates to the field of the preparation of malt intended for breweries or for the manufacture of whiskey, and relates to a process for the preparation of a malt with a smoke taste, called "whiskey malt".

 The invention also relates to a device for implementing this method.

 In accordance with the invention, the process for preparing a smoke-flavored malt, called "whiskey malt", is characterized in that it essentially consists in heating air to 48 "C for approximately 4 hours, and to load it with flavoring smoke by passing under peat drying grids at 40% humidity, this air then passing through the green malt placed on a perforated tray and being evacuated 4/5 by a chimney, then at achieve a temperature rise to 80 "C for about 1 hour to perform a partial caramelization and fixing of flavoring products with air evacuation at-4 / 5th, to keep the hot air at 60" C for about 6 hours with a weak smoke emission and a 4 / 5e evacuation of the air-smoke mixture, the smoke being produced by slow consumption of a layer of peat at 30% humidity above a specially adapted burner , and finally to carry out a fire stop with a temperature rise to 90 "C for e About 3 hours with intense smoke generation by total consumption of the peat slowly consumed during the previous operation in the burner, and total recycling of the air.

 The device for implementing the method described above is constituted by a reinforced concrete enclosure surmounted by a chimney with a height of about 10 meters allowing good evacuation of fumes into the atmosphere, and provided, substantially in its middle part, a perforated tray made of very resistant steel on which is placed a thick layer of malt by a powerful blower of hot air blowing opening in the lower part of the enclosure under the perforated tray, by a or several peat support grids at 40% humidity arranged under the perforated plate, by an indirect air heating circuit, by a peat burner equipped with a differential ventilation system, with a first grid fixed combustion stove for dry wood and dry peat, a second movable grate surmounting the hearth by about 20 cm and used for depositing partially dried peat on the grids provided in the enclosure, and a device from chargem ent of fuel, and by a set of flaps intended for the orientation of the air currents according to the various phases of the process.

 The invention will be better understood thanks to the description below, which relates to a preferred embodiment, given by way of nonlimiting example, and explained with reference to the attached drawing, the single figure of which is a sectional view. of a device for implementing the method according to the invention.

 The process for preparing a smoke-flavored malt called "whiskey malt" according to the invention consists in heating air at 48 "C for approximately 4 hours in a reinforced concrete enclosure 1 provided with a chimney 2 for evacuating the smoke into the atmosphere, and for charging said air with flavoring smoke by passing under grids 3 for drying peat at 40% humidity These grids 3 are arranged under the perforated tray 4 made of very resistant steel intended for loading a thick layer of malt 5, and are loaded with a layer of peat at 40% humidity. The air loaded with flavoring smoke passes through the green malt placed on the tray 4 and is evacuated to the 4 / 5th by the chimney 2, the remaining 1 / 5th being recycled thanks to a flap 6.We then carry out, for approximately 1 hour, a rise in temperature to 800C to carry out a partial caramelization and the fixing of the flavoring products by evacuating the air at 4 / 5th through the chimney 2, then keep the hot air at a temperature of 60 "C for about 6 hours with little smoke, the air-smoke mixture being evacuated to 4 / 5th by the chimney 2, and finally, we fire with a rise in temperature to 90" C for approximately 3 hours with an intense release of smoke, and by completely recycling the air, that is to say by closing the flap 7 of the chimney 2 and by fully opening the flap 6, the flap 8 for taking d fresh air is also closed.

 The circulation of hot air and flavoring fumes is achieved by a powerful blowing fan 9, which opens into the lower part of the enclosure 1 under the perforated plate 4, and the sheath 10 of which is provided with a deflector 11 distributing the air throughout the lower volume of the enclosure 1, so that it can initially perform a partial drying of the peat disposed on the grids 3 before passing through the malt layer.

 The various temperature rises are obtained by means of a peat burner 12 and an indirect air heating circuit 13, for example in the form of a heat exchanger connected to an external heat source.

 The peat burner 12 is provided with a differential ventilation system comprising a draft control flap 14, a first fixed grid 15 serving as a combustion center for dry wood and dry peat, a second mobile grid 16 surmounting the hearth by about 20 cm and serving as a deposit for partially dried peat on the grids 3 and a device 17 for loading fuel. This burner 12 is connected to the enclosure 1 by means of a flap 18 for circulating the peat fumes.

 Smoke generation by the burner is obtained by slow consumption of the partially dried peat on the second mobile grid 16 under the effect of the flames produced by the mixture of wood and peat placed on the first fixed grid 15.

 The peat used for the implementation of the process is advantageously particularly aged, poor in ashes and tars, and has an average combined content of 58% humic substances and lignin, which allow the production of flavoring fumes. To allow good release of flavoring products with intense smoke release and without flame formation, the peat preferably has a humidity of 40%, which is first reduced to 30% by the hot air on the grids 3, then it is brought to the second mobile grid 16 on which it is partially consumed without flame until it is completely dry with a strong release of flavoring smoke. The dry peat obtained is then burned entirely to obtain a total combustion of the cellulose and tars in the hearth on the fixed grid 15. During the flameless consumption of the peat at 30% humidity, the grid 16 is kept constantly naked about 20 cm above the hearth to prevent the formation of flames.

 The wood intended to supply the burner 12 is advantageously hard wood, preferably debarked, very dry and cut in winter, and does not exhibit any degradation, even partial, due to atmospheric conditions or to microbial and plant flora.

 By the passage of hot air through the layers of peat disposed on the grids 3, the volatile flavoring compounds are entrained by water vapor and are fixed on the malt. The peat thus undergoes partial distillation, and produces, when it is used on the grid 16, a smoke that is twice as flavorful.

 For regulating the flaps 6 and 7 for recycling air and opening the chimney 2, a hygrometer 19 is provided which continuously measures the humidity above the malt layer 5 and acts on the motors of said flaps, the air is quickly recycled to maintain smoke throughout the room.

 The regulation of the flaps 14 and 18 is carried out automatically by means of a differential pressure sensor 20, which, to allow a good draft and avoid detachment of the peat layer on the movable grid 16, regulates the opening of said flaps 14 and 18 to maintain a pressure difference of 0.1 atmosphere between the top of the burner 12 and the atmosphere. The control of the fresh air intake flap 8 is also carried out by means of the sensor 20 and as a function of the position of the flap 14. In fact, when the latter is fully open and the air flow is still insufficient, c '' that is to say that the vacuum is greater than 0.1 atmosphere, the flap 8 is controlled to open. For safety reasons, all the shutters are fitted with a manual control allowing direct intervention in the event of unfavorable atmospheric conditions or mechanical failures.

 Of course, the invention is not limited to the mode of; realization described and represented in the appended drawing. Modifications remain possible, without departing from the scope of protection of the invention.

Claims (6)

- CLAIMS -  1. A method of preparing a malt with a smoky taste, called "whiskey malt", characterized in that it essentially consists in heating air at 48 "C for about 4 hours, and in charging it with smoke flavoring by passing under peat drying grids at 40% humidity, this air then passing through the green malt placed on a perforated tray and being evacuated 4 / 5ths by a chimney, then to achieve a temperature rise to 80 "C for about 1 hour to carry out a partial caramelization and the fixing of the flavoring products with evacuation of the air at 4 / 5e, to keep the hot air at 60" C for about 6 hours with a light smoke emission and an evacuation at 4 / 5th of the air-smoke mixture, the smoke being produced by slow consumption of a layer of peat at 30% humidity over a specially adapted burner, and finally making a blow of fire with a rise in temperature to 90 "C for about 3 hours with a release t intense smoke by total consumption of the peat slowly consumed during the previous operation in the burner, and total recycling of the air.  2. Device for implementing the method according to claim 1, essentially consisting of a reinforced concrete enclosure (1) surmounted by a chimney (2) with a height of about 10 meters allowing good smoke evacuation in the atmosphere, and provided, substantially in its middle part, with a perforated plate (4) made of very resistant steel on which is placed a thick layer of malt (5), by an air heating circuit (13), by a flap (7) for evacuating the air through the chimney (2), by an air recycling flap (6), and by a flap (8) for fresh air intake, characterized in that it is equipped with a powerful fan (9) for blowing hot air opening into the lower part of the enclosure (1) under the perforated plate (4) and the sheath (10) of which is provided with a deflector (11) distributing the air throughout the lower volume of the enclosure (1), in that in this lower part of the enclosure (1) are provided, under the perforated plate (4), one or more usieurs grids (3) for supporting the peat at 40% humidity, in that the air heating circuit (13) is an indirect circuit connected to an external heat source, and in that it is equipped with a peat burner (12) provided with differential ventilation comprising a draft control flap (14).  3. Device according to claim 2, characterized in that the peat burner (12) consists of a first fixed grate (15) serving as a combustion center for dry wood and dry peat, -by a second movable grate ( 16) surmounting the hearth by about 20 cm and serving as a deposit for partially dried peat on the grids (3) of the room (1), and by a device (17) for loading fuel, this burner being connected to the enclosure (1), via a flap (18) for circulating peat fumes.  4. Device according to any one of claims 2 and 3, characterized in that the regulation of the flaps (14 and 18) of regulation of draft and circulation of peat fumes is carried out automatically by means of a sensor differential pressure (20) maintaining a pressure difference of 0.1 atmosphere between the top of the burner (12) and the atmosphere, the control of the fresh air intake flap (8) also being carried out by means of the sensor ( 20) and depending on the position of the draft control flap (14).  5. Device according to any one of claims 2 to 4, characterized in that all the flaps are provided with a manual control.  6. Method according to claim 1, characterized in that the peat used is advantageously particularly poor in ash and tar, and has a combined average content of 58% humic substances and lignin allowing the production of flavoring fumes, as well as '' a humidity of 40%.