WO2011148228A1

WO2011148228A1 - Improved fermentation apparatus

Info

Publication number: WO2011148228A1
Application number: PCT/IB2010/052313
Authority: WO
Inventors: Remo Crosato
Original assignee: Lasi S.R.L.
Priority date: 2010-05-25
Filing date: 2010-05-25
Publication date: 2011-12-01

Abstract

Herein described is a method for breaking the skin cap (CP) formed in a tank (12) of a fermentation apparatus for must composed of juice or fruit extract and respective skin, in particular grape must, the must fermenting creating a skin layer called cap in the tank, characterised by providing inflatable means (20) inside the tank, and inflating/deflating the inflatable means in such a manner to break the cap.

Description

IMPROVED FERMENTATION APPARATUS

The present invention refers to an improved fermentation apparatus for must made up of juice, or fruit extract, and respective skin, in particular a vinificator for the grape must.

Known fermentation apparatuses, here using vinification apparatuses as an example, are formed by a tank in which the must can ferment creating a layer of floating skin

(called cap) on a liquid part.

During the vinification the cap is broken up and sprayed with the underlying juice so as to extract its essence and the flavours. Provided for this purpose are proper plunging means that serve for mechanically breaking the cap, submerging it into the liquid part up to a given intermediate level of the tank. The plunging methods envisage the use of one or more pistons adapted to move a single plunging grid, which serves for submerging the entire cap. Otherwise, the cap is sunk little by little, over several passes, using smaller grids and/or more plunging pistons.

All these interventions on the cap are violent and damage the pressed product, lacerating the skin and hence producing dregs.

Patent FR 2 832 353, solely regarding the pressing of the pomace at the bottom of the tank, discloses how to use an inflatable membrane (or pocket). The tank is opened and the membrane is inserted (manually) and then inflated, however this implying contaminating the pomace with air. The membrane can operate on the bottom solely when it reaches and presses against the walls of the tank, hence it must occupy the entire tank which must be necessarily empty. This implies that only a part of the membrane has an active surface on the pressed product. In addition, this system does not allow automated and/or repetitive operations, given the slow process of inflating such a large membrane and the practical impossibility to plung downward. The same solution, practically revealing the same drawbacks, is disclosed by patent FR 2 708 243.

Also known are other presses for the crushed product that use a membrane mounted inside a tank, e.g. WO 2005 051642 or EP 0 533 274. In order to allow pressing even small loads, the membrane is required to have an inflated extension that practically occupies the entire internal volume of the tank, so as to ensure the pressing of the pomace against the draining ducts provided on the walls. The ducts are extended over the entire length of the tank, given that the pomace is pressed on the entire internal surface. Furthermore, the presses neither have circumferential pockets for thermoregulator liquid, nor vents for the gas, given that the pressure of the membrane must be entirely exploited for expelling the liquid. As a matter of fact, the cap does not form in these presses given that the pressing is carried out immediately.

The main object of the invention is that of improving the prior art.

Another object is that of providing a method, and an apparatus suitable to implement it, capable of better maintaining the organoleptic characteristics of the must breaking the cap in an efficient but non- violent manner.

Another object is that of providing a method, and an apparatus suitable to implement it, capable of allowing efficiently oxygenating and/or wetting the cap.

Such objects are attained through the methods defined by claims 1-5.

The key element of the invention is that of having inflatable means, or equivalently one or more inflatable elements (in brief IE), inside the tank. Only the term HE shall be used hereinafter for the sake of brevity.

The dilatation of the IE may serve to crush, break or press the cap and/or for compressing gases and/or the liquid must present inside the tank. The reduction of the IE may serve to provide space for and distribute the broken cap and/or for making dilate the gases in the tank and/or for drawing back the liquid must (or generally a fluid) from outside. All this, as explained, allows providing a vinificator with new functionalities and characteristics.

In order to implement each or some of the steps of the abovementioned methods, the invention provides for a fermentation apparatus suitable for the purpose according to claims 6-19.

The IE may be mounted permanently or removably inside the tank, or fixed onto the end of plunging means, these being removable too, so as to manually insert it into the tank and break the cap by inflating the EG. The plunging means provided with the IE may be permanently integrated into the tank.

The IE is preferably positioned inside the tank at the point where the cap is formed during fermentation, for maximum efficiency while breaking it, e.g. at a distance of about ¼ to ¾ of the length of the tank starting from the bottom, preferably from ½ to ¾. Generally, it is advisable to position the IE at a height - inside the tank - where the cap is usually presumed to be formed and distant from the expulsion means - where provided - to avoid causing damage thereon.

The tank, contrary to a press, preferably

- comprises circumferential pockets for thermoregulator liquid over the entire or most part of the side walls, and/or

- comprises controlled flow-rate venting means for the fermentation gas; and/or

- it is fixed onto the ground lying on support legs (it is not a rotary drum); and/or - it is provided with expulsion means for expelling the pomace which are positioned on the bottom of the tank.

A press is not provided with mechanical members adapted for expelling the pomace, in that they would come into contact with the pressing membrane during the inflation step, lacerating it.

In the presses, the expulsion step for the exhausted pomace occurs by rotating the drum or tank in which it is held. The rotation of the drum also allows moving pomace in the press itself during the pressing steps, and this allows both cleaning the must draining ducts, which are clogged after each pressing process, and for supplying to the same ducts non-exhausted pomace and soaked with must. As a matter of fact, the pressing step allows draining - at most - a pomace layer 15 cm thick and overlaying the ducts; the rest of the pomace is not drained, given that the first 15 cm form an almost airtight cap and do not allow the must to flow.

By mounting, whether permanently or not, an IE inside the tank the vinificator acquires advantageous automated functionalities.

For example one may use a pipe not only serving as a support for the IE but also as a collector for the fluid to inflate it. The pipe, for example, may be fixed with a flange onto the roof of the tank. The same pipe - bearing the IE - may be easily dismounted at the end of the vinification to clean the EG, for possible reparation thereof in case of breakage, and for transforming the vinificator into a perfect tank for storing the wine.

The cap-breaking operation occurs by inflating the IE, which widens on one side or at the centre of the cap. Not only is the breaking of the cap efficient and repeatable, due to the fact that the crushed or broken portion of the cap is determinable by the final expanded volume of the IE, but it is also delicate, due to the fact that the mechanical action is performed gradually and without rigid crumbling members operating in percussion. The plunging operation using the IE can be operated with a closed or open tank.

Preferably, the IE is mounted suspended at the centre of the tank on a support, for breaking the cap 360° around it. However, it may also be good to arrange the IE on a wall of the tank, at the same height, or on the bottom of the frusto-conical tank, wherein the variation of the level of the must caused by the inflation/deflation is enough for the cap to crumble when sliding up and down on the inclined walls of the tank. A frustoconical tank and the deriving effect is however useable in all variants described herein.

Alternatively, or in combination, the IE may serve to regulate the pressure in the tank: inflation thereof causes an increase of the internal gas pressure, without for example having to inject supplementary gas from outside, while deflation thereof decreases the pressure. In this case, the tank is a closed container. Preferably the tank is provided with controlled vent means or having an adjustable threshold and/or with gas injecting means for reintroducing gas into the tank. The coordinated action of the vent means, which correct the internal pressure lowering it, and the inflation of the IE or the injection of external gas with gas restoring means , which correct the internal pressure increasing it, allow an accurate control of the pressure, e.g. at least with the resolution of 0.01 bar.

The sole expulsion of disposable gas towards the external environment when the IE is inflated may for example be obtained through simple vent means, for example valves, which shall allow natural passage of gases set under overpressure.

The variation of the internal volume of the tank caused by the variable dimensions of the IE may also, or solely, be exploited for oxygenating the must, or breaking the cap by means of pressure and/or gas, or wet the cap with must. This occurs by associating to the vinificator suitable inlets and outlets for internal fluids (gas or liquid), preferably provided with valve means for controlling the flows. As a matter of fact, inflation causes the IE to compress the internal volume of the gas and/or liquid in the tank and can cause discharge thereof to the outside. When the IE is deflated, the tank is instead subjected to a depression which may naturally suction fluid from the external. Thus, air or must may be suctioned into the must, beneath the cap, in such a manner that when raising it impacts and crumbles the cap; or must may be drawn back into the tank and poured over the cap to wet it. In practice the IE is used as a plunger. An inlet conduit may be preferably provided for inletting external gas or air (for example a pipe drawing free air) which leads to the tank at a level where the must is in use. The inlet conduit may be provided with valve means, for example check- valves, to allow the sole unidirectional entry of air.

Or to the main tank one may add

an auxiliary tank for storing fluid,

a first piping system for letting the auxiliary tank communicate with the top part of the main one,

a second piping system for letting the auxiliary tank communicate with the bottom or a point inside the main tank located between the bottom and about the half-height, and valve means on each piping system.

This equipment allows transferring gas into the auxiliary tank when the IE is inflated, and drawing it back beneath the cap when the IE is deflated, with the result of impacting the cap with gas under pressure breaking it. Or the must may be transferred into the auxiliary tank when the IE is inflated, and let it fall over the cap when the IE deflates, with the result of wetting the cap and extracting the flavours.

In a further variant, added to the main tank may be a tank or auxiliary container, with elastically extensible or inflatable volume. This auxiliary tank serves to recover the C0₂ or nitrogen (or any other gas) present in the tank, and which would otherwise be expelled and hence lost due to the inflation of the internal IE. During the deflation of the IE, the gas stored in the external tank will naturally flow into the main tank, thus avoiding having to reintroduce additional inert gas. The costs are definitely lower than the case wherein at each inflation cycle the gas is dispersed into the environment, and at each deflation the gas is reintegrated with new gas.

The use of the auxiliary tank allows controlling - in a simple but efficient manner - the pressure in the main tank, by exploiting the equivalence or difference of volume between the internal inflated IE and the inflated inflatable auxiliary tank.

Used additionally or in combination with the inflatable tank, may be a rigid tank for storing the must and/or the pressure gas. Such equipment allows fully exploiting the possibility of having IE inflation cycles also exploiting the possibility of varying the internal pressure of the main tank and/or the volume of the must contained therein, and cycles wherein - instead - the pressure is preferably maintained at a constant pressure inside the same.

Generally, the described auxiliary tanks may be applied and fixed externally with respect to the main one or obtained by partitioning the latter.

The IE may be of various dimensions, and a good compromise between the load capacity of the apparatus and vinification efficiency requires that the IE - when fully inflated - fills a volume lower or equivalent to 60% of that of the tank, preferably lower or equivalent to 50%.

The apparatus preferably comprises an elaborating unit configured to drive and/or control the inflation/deflation of the IE and/or the state of the valve means and/or the output of gas pressure sensors and/or the level of the must and/or timer means (useful for managing the process cycles).

The invention also comprises the developed program so that the elaborating unit controls the means of the apparatus so as to execute part of or fully the abovementioned methods.

The invention and advantages thereof shall be clearer from the description that follows of some preferred embodiments, illustrated in the attached drawing wherein:

Figure 1 shows a transparent front view of a vinificator according to the invention;

Figure 2 shows a transparent side view of a second vinificator according to the invention;

Figure 3 shows a transparent side view of a third vinificator according to the invention;

Figures 4-5 show a series of configurations for the vinificator of figure 3;

Figure 6 shows a transparent side view of a fourth vinificator according to the invention;

Figure 7 shows a transparent side view of a fifth vinificator according to the invention;

Figures 8-12 show a series of configurations for the vinificator of figure 7;

Figures 13 and 14 show a transparent side view of a sixth vinificator according to the invention in two different configurations;

Figures 15 and 16 show a top sectional view of the vinificator of figures 13 and 14, according to planes XV and XVI respectively;

Figure 17 shows a top sectional view of a seventh vinificator according to the invention;

Figures 18-21 show another series of configurations for the vinificator of figure 7.

Figures 22-23 show another series of configurations for an eighth vinificator.

Shown in figure 1 is a vinificator 10 comprising a cylindrical tank 12 for must M mounted at the top part of which is an inflatable membrane 20 suspended on a conduit 22, e.g. a pipe. Due to blow/injection means 24 and also preferably suction means, e.g. a blower or turbine, a fluid (e.g. air) may be pumped into the, or suctioned from the, membrane 20 for inflation or deflation thereof. Formed over the must M is a cap CP composed of pomace. A valve 26 allows venting - in a controlled manner - a gas contained under overpressure in the tank 12. Associated to the means 24 may be a valve for depressurising the membrane 20.

The bottom FF of the tank 12, preferably inclined for better evacuation of the pomace at the end of vinification, is accessible through a lower hatch CH, through which the pomace is extracted. This characteristic may be present in all variants of the invention.

Each vinificator may also be possibly and preferably be provided with means for expelling the pomace at the end of fermentation, such as for example those described hereinafter.

Shown in figure 2 is a vinificator 30 identical to the previous one, except for the fact that its tank 32 for the must M is frustoconical, with the larger base serving as bottom. Identical reference numbers shall be used here and hereinafter to indicate identical components.

Shown in figure 3 is a vinificator 50 comprising a cylindrical tank 52 for must M mounted at the top part of which is an inflatable membrane 58 suspended on a conduit 54, e.g. a hollow support for the passage of fluid. Blow/injection means 56 allow pumping a fluid into the, or suctioning it from the, membrane 58 for inflation or deflation thereof. Formed over the must M is a cap CP composed of pomace. A valve 60 allows venting - in a controlled manner - a gas contained under overpressure in the tank 12. Associated to the means 56 may be a valve for depressurising the membrane 58. A conduit 62 is arranged vertically outside the tank 52 and communicates therewith at a point located at about half the height of the tank 52. The length of the conduit 62 slightly exceeds the roof of the tank 52 and here, at the open air end, it is provided with a check-valve 64. At the other end, the conduit penetrates into the tank 62 with a horizontal section 66, submerged into the must M.

Described referring to figures 3-5 is the operation of the vinificator 50.

The process of breaking the cap CP floating on the must M starts in figure 3.

The means 56 are used to inflate the membrane 58, which is expanded inside the cap

CP that surrounds it. By expanding, (figure 4) the membrane 58 crumbles and deforms the cap CP, and simultaneously causes an increase of the level of the must M and thus an overpressure in the gases GS (especially C0₂) in the tank 52. These gases GS exit from the valve 60 which is, in the meanwhile, opened and controlled. (One or more simple safety valves capable of allowing venting both the overpressure and depression may also be used for such purpose).

Then, the membrane 58 (figure 5) is deflated. The cap CP reduces in thickness, the internal empty volume of the tank 52 increases and the pressure thereof decreases. There is a suction of external air through the valve 64 which passes through the conduit 62 and the section 66 to end up in the must M, beneath the cap CP. Rising, the air AR impacts the cap CP, subjecting it to mixing, further breaking and oxygenation.

The effect of breaking the cap CP as described above is also obtained in the vinificators 10 and 30, inflating the membrane 20. In this case, the gases and the air will exit and enter into or from the valve 26, or from an open hatch on the roof of the tank. The tank 32 has the advantage lying in the fact that the cap CP - rising and coming down along the inclined side walls thereof - will first be broken and then defibred, ending up expanding further.

Figure 6 shows a vinificator 70, entirely and functionally identical to the vinificator 50 except for the position of the conduit for injecting the external air. Such conduit 72 is or it is adjacent to the mechanical support 54 for the membrane 58. The conduit 72 at the open-air end is provided with a check-valve 74, while the other end penetrates vertically into the tank 52 up to the lowest point of the membrane 58, or beyond. During the operation, the vinificator 70 will allow the injection of air AR into the centre of the tank 52, which will rise along the sides of the membrane 58 impacting a larger surface of the cap CP.

In order to increase the breaking and/or oxygenation effect, in the described variants and those that follow the membrane may also be inflated with air, which may be released into the must beneath the cap.

Figure 7 shows a vinificator 80, entirely and functionally identical to the vinificator 50 except for the addition of a storage tank 82 arranged above the tank 52. The tank 82 is in communication with the conduit 62 and with a second conduit 84 which leads to the roof or into the tank 52 and having a flow control valve 84. Present on the tank 82 is a vent valve 88.

The vinificator 80 may operate according to two different methods.

In the first method (figures 8-12) the cap CP is sprayed with must; the valves 64, 86, are closed. When the must M generates a cap CP (figure 8) the process for inflating the membrane 58 (figure 9) begins by opening valve 64 and valve 88. The volume increase of the membrane 58 causes a variation in volume of the must M, alongside increasing the pressure (with the pressure regulating valve in the tank closed) inside the vinificator 80. Such pressure increase pushes the must through the conduit 62 into the tank 82 (arrow ml), and here the must pushes air outside through the valve 88. The volume of the transferred must is compensated in the tank 52 by the entry of gas or air from outside, through a pressure regulating valve 87, preferably unidirectional.

The more the membrane 58 expands, the more must M ends up in the tank 82 (figure 10). Then, the valve 64 is closed, the valve 86 is opened and the membrane 58 is deflated (figure 11). The must contained in the tank 82, by gravity and suctioning, passes through the conduit 84 and falls into the tank 52 over the cap CP, which was crushed by the membrane 58. By passing through the cap CP the must wets it and extracts flavours and characterising substances thereof. When the tank 82 is emptied (figure 12) the cap CP is crumbled, wet and well oxygenated due to the fact that at each emptying the tank 82 is filled with fresh air which oxygenates the must that arrives there afterwards.

Generally, the internal pressure in the tanks 80 and 52 - during the various steps described above - will be regulated by the two pressure regulating valves 88 and 87.

In the second method of operation, the technical effect is the oxygenation and delicate breaking of the cap.

From the configuration of figure 7, where the valves 64, 86, 88 are closed and the must M has generated a cap CP, the process for inflating the membrane 58 (figure 18) begins by opening also the valve 86. The valves 87 and 88 are closed. Increasing the volume of the membrane 58 causes a variation in the level of the must M, which pushes the gas GS present above the cap CP into the tank 82 through the conduit 84.

Upon complete inflation of the membrane 58 the pressure in the main tank 52 and in the storage tank 82 is maximum (figure 19).

At this point, the valve 86 is closed and valves 64 and 87 are opened. The gas stored in the storage tank 82 is insufflated beneath the cap CP creating macrobubbles BL which crush it (figure 20). The membrane 58 is deflated simultaneously or non-simultaneously. When the membrane 58 is entirely deflated, the pomace cap is entirely crumbled (figure 21); the pressures inside the tanks 52, 82 are entirely balanced and the cycle may be restarted.

Figure 13 shows a variant 90 of a vinificator, identical to that of figure 1. Though not shown, the vinificator 90 may comprise an aeration conduit like the conduit 62 or an auxiliary tank like the vinificator 80 and respective conduits and flow regulation means, as well as an external inflatable tank for storing C0₂ or gas as better described hereinafter.

The peculiarity of the vinificator 90 is that the membrane, herein indicated with 20a, is mounted on an internal side wall of the tank 12. The function of the membrane 20a is analogous to that of the membranes described previously. The advantages of these variants lie in the fact that the membrane creates less problems during the operations of internal cleaning of the tank 12 and it exploits the wall to withstand the thrust-reaction of the cap CP. Thus, less massive anchoring onto the tank is sufficient.

Figure 14 shows the inflated membrane 20a and illustrates the variation of the form of the cap CP. Thus, the cap CP may be subjected to all the operations described above. Figures 15 and 16 show a top sectional view of the perimeter of the membrane 20a, respectively deflated and inflated. The ratio between the maximum extension of the membrane 20a and the total area of the tank 12 may be appreciated.

Figure 17 shows two membranes 20b, 20c mounted on a diameter of the tank 12. Each is identical to the membrane 20a. It should be observed how the use of two or more membranes may increase the breaking surface on the cap CP, to the advantage of greater aeration and/or wetting. Arranged on the wall of the tank 12 may be perforated baffles or drain ducts 92 for collecting the juice of the cap CP subjected to pre-pressing. The baffles 92 have a limited length, preferably a maximum of about 70% of the height of the tank 12, given that they are required only where the cap CP is formed and crushed. In this case, contrary to the action of a press, this operation aims at squeezing the cap and not separating the liquid must from the solid part.

Above all, it should be observed that in case of very thick pomace caps (for grapes with berries whose liquid/skin part ratio favours skin), the inflatable means of the present invention may also be advantageously used for pressing the cap at the end of fermentation in the tank.

Several membranes may be used inside a tank, e.g. with combinations of the described positions, in order to increase the effect on the cap.

In any case, the described membranes as inflated occupy, alone or as a whole, solely a fraction of the internal volume of the tank. The maximum volume thereof is dimensioned starting from the nominal load of must of the apparatus, and considering the fact that the liquid must is incompressible, and so is the compacted pomace. A good compromise is, for example, between 30 and 70 % of the internal volume of the tank, preferably about 50%, in such a manner to be able to process even smaller amounts of crushed product with respect to the optimal amounts processable according to the invention.

Several external conduits and/or outlets for gas or must in a tank may also be used, to increase the amount of gas or must and thus the effect on the cap.

As mentioned, it is preferable to provide each vinificator with means for expelling the pomace at the end of the fermentation. Such means (blades or other mechanical members) are preferably present at the bottom of the vinificator, so as not to interfere with the action of the membrane in any manner whatsoever or lacerate it by impacting them. As a matter of fact, the pressing step may be highly optimized through means arranged at the bottom of the tank to divaricate and/or break the cap when it lies on the bottom of the tank. Opening and breaking the deposited cap increases the exposed surface from which the juice may exit.

As a preferred variant, simple but efficient, the divaricating means comprise a rotatable member provided with projections (e.g. baffles, fins, teeth, combs, etc.) adapted to cut the cap when the member rotates. Opening the cap increases the drain surface thereof, and this increases the efficiency and the pressing quality.

Preferably, the projections are arranged radially each at a different distance from the centre of rotation of the rotatable member. In this manner, the cutting action of the projections is maximum.

Preferably the rotatable member is automated through motor means, e.g. a step motor, adapted to rotate it by a fraction of round angle at each pressing cycle. Thus, at each pressing the cap is widened at a different angular sector. By the end of the cycle, the entire cap has been opened and pressed.

At the end of the pressing process, the exhausted pomace CP is extracted from the tank also thanks to the blade which -rotating - may scrape the bottom and push the pomace near the discharge openings.

Should the blade be provided with nozzles for the gases entering from outside, the blade also serves as a movable gas supplier, thus improving the oxygenation of the cap.

The vinificator 100 (see figure 22) comprises a cylindrical tank 112 arranged in which is an inflatable membrane 120. Connected at the roof of the tank 1 12 is a pipe 162 in communication with an external inflatable bag or membrane 160, or generally an inflatable and/or elastically variable volume tank. The bag 160 is kept stretched by a support element or bracket 164.

During the crushing operation of the cap CP (figure 23) there occurs the progressive inflation of the membrane 120. The inflation of the membrane 120 expels gases from the tank 1 12, such gases being stored in the bag 160. The bag 160 is preferably designed to be inflated as much as the membrane 120, in such a manner that the internal pressure of the tank 1 12 remains substantially constant. Basically the bag 160 serves as an outer lung chamber for receiving over-pressured gases in the tank 112. By deflating the membrane 120, the gases in the bag 160 are drawn back into the tank 112, restoring the pre-existent balance.

The same gas decanting may occur during the pressing step of the cap, when the membrane 120 is deflated to press against the cap CP deposited at the bottom of the tank 112, or in the step of discharging the exausted pomace, when the membrane 120 is deflated again.

The use of the bag 160 allows controlling - in a simple but efficient manner - the pressure in the tank 1 12. By varying the elastic and dilatation characteristics of the bag 160 one may set the final internal pressure in the tank 1 12. The final volume of the inflated bag 160 being referred to as Vf and that of the inflated membrane 120 being referred to as Vm, the final internal pressure will be the same if Vf = Vm, greater if Vf < Vm, and lower if Vf> Vm.

Not only does the simple mounting of a different bag allow varying the final internal pressure in a simple and accurate manner, but it is also possible to obtain a pressure control otherwise attainable solely by means of sensors, valves and automatic controls. Thus, this allows saving on production costs and reducing the complexity of the machine.

Preferably all these operations of the vinificators described above are managed by an elaborating unit or computer, which particularly controls the actuation of the pistons, and/or the inflation/deflation of each membrane, and/or the rotation of the blade through respective position and pressure sensors, and/or the driving of motors, actuators or valves, and/or the system for regulating the pressure in the tank and/or the system for introducing/expelling air or inert gases into the and from the tank.

The elaborating unit may be programmed to perform periodic operating cycles like the ones described beforehand or timed combinations thereof.

It should be observed that installed or memorized in the elaborating unit is a program adapted to manage and coordinate all or some of the operating steps of the vinificator. Such program is equally comprised in the invention.

Claims

1. Method for breaking the skin cap (CP) formed in a tank (12) of a fermentation apparatus for must composed of juice or fruit extract and respective skin, in particular grape must, the must being able to ferment creating a skin layer - called cap - in the tank, characterised by

- providing inflatable means (20) inside the tank,

- inflating/deflating the inflatable means in such a manner to break the cap.

2. Method for oxygenating and/or breaking the skin cap (CP) formed in a tank (12) of a fermentation apparatus for must composed of juice or fruit extract and respective skin, in particular grape must, the must being able to ferment creating a skin layer - called cap - in the tank,

characterised by

- providing inflatable means (20) inside the tank,

- inflating the inflatable means to expel gas and/or must from the tank,

- deflating the inflatable means to draw back gas and/or a fluid from outside the tank conveying it beneath the cap, in such a manner that upon rising in the must the gas or fluid breaks and/or oxygenates the cap.

3. Method according to claim 2, wherein the expelled gas or must are stored in an auxiliary container (82, 160) and such stored gas or must are drawn back into the main tank through the deflation of the inflatable means.

4. Method according to claim 3, wherein an inflatable container (160) or container with expansible volume is used as auxiliary container.

5. Method for spraying - with must - the skin cap (CP) formed in a tank (52) of a fermentation apparatus for must composed of juice or fruit extract and respective skin, in particular grape must, the must being able to ferment creating the skin layer called cap in the tank,

characterised by

- providing inflatable means (58) in the tank,

- inflating/deflating the inflatable means to expel liquid must from the tank towards a second storage tank (82),

- deflating the inflatable means to draw back the must from the storage tank making it fall over the cap.

6. Fermentation apparatus (10) suitable to carry out each or some of the steps of a method according to the preceding claims,

the apparatus comprising a tank (12) for must composed of juice or fruit extract and respective skin, in particular grape must, adapted to let the must ferment creating a skin layer called cap,

characterised in that it comprises inflatable means (20) which are mounted permanently inside the tank and are configured to be inflated/deflated in such a manner to occupy - when inflated to the maximum - solely a part of the internal volume of the tank, so as to reduce the actual internal volume of the tank.

7. Apparatus according to claim 6, wherein the inflatable means are mounted suspended at the centre of the tank at a height where - during use - the cap is formed, at a distance from the bottom of about half to ¾ of the tank.

8. Apparatus according to claim 6, wherein the inflatable means (20a) are mounted on an internal wall of the tank.

9. Apparatus according to any one of claims 6 to 8, wherein the tank (32) is frustoconically shaped with the larger base defining the bottom.

10. Apparatus according to any one of claims 6 to 9, comprising vent means (60), controlled or with adjustable threshold, for the gases contained in the tank and/or gas injection means for injecting or allowing gas to enter into the tank, the latter being a closed container, wherein said vent means and said gas injection means are adapted to regulate the pressure of the gases inside the tank during the inflation/deflation of the inflatable means.

1 1. Apparatus according to any one of claims 6 to 10, comprising an inlet conduit (62) for external fluid leading into the tank at a level where in use the must is, the conduit being provided with valve means (64) which are configured or regulated to allow an entry of external fluid solely when drawn back due to pressure difference by the inflatable means that are being deflated.

12. Apparatus according to claim 1 1, wherein the inlet conduit is a conduit (62) with free-air suction provided with a check-valve (64) adapted to allow unidirectional entry of air into the tank.

13. Apparatus according to any one of claims 6 to 12, comprising a mechanical support (54) to which the inflatable means are anchored and suspended inside the tank, in such a manner that the inflatable means can be inflated and push the cap on a 360° perimeter thereof.

14. Apparatus according to claims 11 and 13, wherein the inlet conduit for external fluid (72) constitutes or composes the mechanical support (54) to which the inflatable means are anchored and suspended inside the tank.

15. Apparatus (80) according to any one of claims 6 to 14, comprising

- an auxiliary tank (82) for storing fluid,

- a first piping system (84) for letting the auxiliary tank communicate with the top part of the main one,

- a second piping system (62) for letting the auxiliary tank communicate with the bottom of or a point inside the main tank, said point being located at an intermediate level between the bottom and about half height, and

- valve means (64, 86) on each piping system adapted to stop or allow the flow of fluid.

16. Apparatus according to any one of claims 6 to 15, wherein the inflatable means are designed in such a manner that - when fully inflated - they fill a volume less than or equivalent to 50% of that of the tank.

17. Apparatus according to any one of claims 6 to 16, comprising

- an auxiliary inflatable- or expandable-volume tank (160),

- a piping system (162) for letting said inflatable tank communicate with the main one where - during use - gases build up or are present.

18. Apparatus according to any one of claims 6 to 17, comprising an elaborating unit configured to run and/or control

- the inflation/deflation of the inflatable means and/or

- the state of valve means and/or

- the output of the gas pressure sensors and/or

- the level of the must and/or

- timer means,

in such a manner to make the apparatus execute one or more of the steps of one of the methods defined in claims 1 - 5.

19. Apparatus according to any one of claims 6 to 18, comprising perforated baffles or draining ducts (92) present on the internal walls of the tank (12), the baffles or the ducts having a maximum length of about 70% of the height of the tank.

20. Program designed to run on an elaborating unitof an apparatus according to claim 18, comprising instructions that - upon execution - are adapted to make the apparatus perform one or more steps of one of the methods defined in claims 1 to 5.