FR2495920A1 - METHOD AND DEVICE FOR REDUCING OXIDATION AND EVAPORATION OF COFFEE IN A CONTAINER WITH SPOUT - Google Patents

Abstract

THE SHELF LIFE OF A QUANTITY OF COFFEE CAN BE EXTENDED IF A SUPRA-ATMOSPHERIC PRESSURE IS MAINTAINED INSIDE A POT 10 OF THE SPOUT 24 TYPE AND IF THE COFFEE IS SPILLED FROM THE BOTTOM FROM THE POT. THE SHELF LIFE OF A QUANTITY OF COFFEE CONTAINED IN A POT CAN ALSO BE EXTENDED IF AN APPRECIABLE TEMPERATURE DIFFERENCE BETWEEN THE SURFACE OF THE COFFEE CONTAINED AND THE CONTENTS OF THE BOTTOM OF THE POT, AND IF THE COFFEE IS POURED. FROM THE BOTTOM OF THE POT. THE REDUCED SURFACE TEMPERATURE, COMPARED TO THE HIGHER "CONSUMPTION TEMPERATURE" WHICH IS MAINTAINED AT THE BOTTOM OF THE POT FROM WHERE THE COFFEE IS PIPED, RESULTS IN A SIGNIFICANT REDUCTION IN OXIDATION AND A SPECTACULAR DECREASE IN EVAPORATION, AS MAY BE RECOGNIZED FROM THE EXPONENTIAL NATURE OF THE VAPOR PRESSURE CURVE FOR WATER IN THE TEMPERATURE RANGE IN QUESTION.

Description

The alteration of the coffee, that is to say the loss of its flavor

  and its aroma "fresh" or palatable, is mainly due to

  oxidation and evaporation. In a coffee pot

  8 to 12 cups, the alteration is usually sufficient

  completed within one to two hours, depending on the

  consumption rate, to make the remaining coffee undrinkable.

  The role of oxidation alone in altering the flavor of coffee is obvious to anyone drinking coffee from a "Thermos" bottle. The first time the bottle is opened, whether after one or several hours, the coffee has a perfectly fresh goit. If you close the bottle by leaving a small amount of coffee, for example half a cup, it will quickly deteriorate, as evidenced by the bad taste it has when you consume it for example

  one hour later. Evidently, there was no evapo-

  large amount from the closed bottle, but fresh air was introduced at the time the first cup was poured. The altering role of evaporation is even more

  obvious, because the coffee solution is concentrated by evaporation.

  The idea of extending the shelf life of coffee, that is, the period during which it retains the flavor and aroma of freshly brewed coffee, virtually eliminating its exposure to the atmosphere, while maintaining the The conventional idea is to hermetically isolate the main bulk of the coffee from a conventional pourer-type coffee pot. is contained in relation to the atmosphere. The top of the pot is hermetically sealed by a deformable lid, for example a bellows or a bag, and the coffee which is contained at the lower end of a small diameter pouring spout which opens into the coffee pot. in the vicinity of the bottom of it serves as hr-d-ulic closure between the atmosphere and the main mass of the coffee contained in the pot.

  The result is that the only oxidation that can

  coming happens at the top level of the coffee in the spout duct. If the spouted duct is given a sufficiently small section, the amount of coffee that is oxidized and can pass into the main contained coffee tank through the hydraulic closure is negligible in the first 4 to 8 hours, following the cross section of the pouring duct. Similarly, the only loss in the atmosphere that can occur by the evaporation mechanism takes place at the level of the small coffee surface in the spout duct,

  because there is inherently a state of equilibrium

  gas / liquid sprayable surface in a hermetically sealed container

  cally. In other words, the patented idea is to pour the coffee from the pot 1, while keeping the top of the pot tightly closed by means of a movable cover which follows the level, keeping the pot at bay. it is atuospheric on coffee in such a way that it. can be paid without creating a

blocking by vacuum.

  The described invention eliminates the need for a cover

  mobile key which follows the level; while at the same time reducing the oxidation and evaporation of a quantity of coffee contained in a pot, so as to prolong in this way its shelf life. The aims of the invention are twofold:

  (1) Introduce a notion of "restricted means of penetration

  ture "to obtain, in a pot having no moving element, an extension of the shelf life close to that given by the patented idea of using a closed pot in a completely hermetic manner; and 2) Introduce a notion of "temperature difference" to prolong the shelf life of coffee without the need

  a special cover assembly, as provided for a

  hermetic sealing or lice; the production of means of restricted air penetration; indeed, the top of the pot can present the characteristic of wide central opening of the classic pots

  automatic drip coffee makers.

  These goals are exposed separately: in fact, under conditions of high consumption in which, for example, a pot full of coffee is typically consumed in the space of one or two hours, the notion of "temperature difference" will be quite sufficient to keep the coffee fresh, whereas with longer periods of consumption, the concept of "restricted air penetration means" will extend the shelf life by up to four to five hours. When the two concepts are combined in a single pot, as also described in this memo, the extension of the shelf life is six to eight

  hours, approaching that of the patented hermetic pot.

  The common denominator and the

  the two concepts is that coffee is

  delivered from the immediate vicinity of the bottom of the pot.

  In order to adapt the concept of "restricted air penetration means" to a conventional blown borosilicate glass pot which does not have a spouted conduit, the patented idea of substantially hermetically isolating the main mass of coffee contained in relation to the atmosphere by means of a hydraulic closure constituted by the column of liquid in a small-diameter spouted pipe which extends to the bottom of the pot, so that, in fact, we pour from the bottom of this pot. However, the spouted conduit extends upwardly from the bottom of the pot, within the confines of the peripheral wall thereof, to exit through a lid assembly that closes the top end.

open pot.

  If the open top of the pot was completely closed

  In the absence of a movable member depending on the level to maintain the atmospheric pressure on the coffee, it would be impossible to distribute coffee through the spout duct, because of the blockage by the vacuum that would occur. The

  the need for a mobile element according to the level can be eliminated.

  n & iî- and - Y-f fatilamentL ditribiu, without perédre pratigliement any of the advantages dl a-p farm so

  completely hermetic, provided that means of penetration are

  airflow sufficiently small so that the vapor pressure of a quantity of coffee contained in the pot is

  above atmospheric pressure. The result is a firm

  vapor barrier, at the level of the penetration means

  of air, which opposes the entry of air at all times, except

  As soon as coffee is actually dispensed through the Pour Beaker. The volume of air entering during pouring is obviously negligible compared to the volume that enters a conventional open jar for the duration of a

  period of one to several hours. In other words, the oxidation

  produced by this minimal amount of air introduced during

  as it is poured has practically no alteration

  within a period of several hours.

  A concomitant and important consequence of the use

  restricted means of air penetration is the evaporation

  significantly reduced compared to a classic pot

  hence the steam can escape freely.

  Indeed, when the vapor can escape freely, the equilibrium at the gas / liquid interface is never reached and the evaporation can continue until the end. On the other hand, in a closed system, partial pressures of the coffee vapor will increase until a state of equilibrium is established; at this moment, for each molecule that escapes through the liquid / gas interface in gaseous form, another molecule goes back from the gaseous form to the liquid form and, at

  In this respect, no further loss of liquid volume by evaporation

  tion does not occur. This is what happens with the patented process, according to which the space above the coffee contained in

  the pot is closed completely hermetically.

  A similar result can be obtained by the restricted air penetration means herein described and claimed which impose a counterpressure on the enclosed gas phase, so that an equilibrium state is approached with the result that the return percentage of the gaseous phase in the liquid phase is close to the percentage of escape from the liquid phase to the gaseous phase, the consequence. is, over a period that can reach to. 8 hours depending on the rate of emptying the pot by coffee distribution, is a negligible loss of volume of coffee by evaporation. Real tests, conducted with a volume of six cups in a pot of twelve cups, with a

  coffee temperature maintained at 800C and a single penetration hole

  1.52 mm in diameter, showed that the evaporation loss was less than one third of a cup,

  contrast with a loss of two and a half cups per evapora-

  from a classic pot. It is obvious that the more

  air penetration will be small, the closer we get to

  the equilibrium state and the loss of volume by evapo-

ration will be small.

  In summary, with respect to the means of air penetration which, for the purposes of this disclosure, will be considered as being constituted by a single pinhole in the lid, otherwise sealed, of a coffee pot that passes through a spouted duct extending to the vicinity of the bottom of the container, the means of air penetration are necessary so that one can pour the coffee, in the absence of any moving element, without happening a blockage by vacuum. In view of their role in reducing oxidation, the air inlet means must have a total area sufficiently small to produce a counterpressure or supra-atmospheric pressure inside the pot to prevent the penetration of air. air, by means of a vapor closure, through the means of

  air penetration when the pot is in the upright position, ie

  say outside the times when coffee is poured. The role of restricted air penetration means in reducing volume loss through evaporation is to cause partial pressures across the gas / liquid interface to

of balance.

  Since the general object of the invention is to ensure that the entire contents of a coffee pot can be consumed without having to throw the last few cups because they have taken an unpleasant taste in It is difficult to see how important it is for a small diameter spouted pipe to extend almost to the bottom of the container and remain immersed all the time while coffee is lowered. Thus, at the time when the coffee rake has been strongly lowered, for example up to the mark of two or three cups, oxidation and evaporation will, if allowed to intervene, play a much more distorting role than when full coffee pot is initially prepared. In the first place, the smallest volume of coffee will be at a higher temperature than the initial filling state of the pot 'assuming

  that one uses a stove-coffee automa-iq.- to Ocoule-

  standard type) and, like most other chemical reactions, oxidation is accelerated by

  high temperatures, as well as the rate of evaporation.

  Secondly, the alteration due to oxidation progresses more

  quickly because of the proportional exposure

  larger in a small volume, an equal evaporation rate producing a much higher proportional concentration in a small volume compared to a large volume of liquid. If the lower end of the pipe & spout does not

  remain immersed when the level of coffee decreases, the

  As the hydraulic air is drawn off the air traps the remaining coffee and oxide, the equilibrium approach through the liquid / gas interface is destroyed, allowing evaporation to continue until completion. That's why a lot of jars

  coffee of the electric or electric percolator type, comprising

  both externally placed beak outlets do not

  not come to use with the present invention. In any case, they have at least a portion of the mouth of the spout in the pot which is% a level clearly above the bottom of the pot, and as soon as this upper level of the mouth of the spout in the pot has been reached by the fact that the coffee level is falling, the rest of the coffee is quickly altered by oxidation and evaporation. Therefore, the entire open bottom end of the spout duct must be placed

  stay completely immersed at all times, the hydrau-

  It remains intact until the coffee has been poured almost completely, otherwise the essential advantage of preserving the good taste of the remaining coffee is lost. In practice, with various 8 to 12 cup coffee pots, it is best to ensure that the hydraulic closure will remain intact, if possible, until the penultimate cup has been poured. , to leave only one cup exposed to the altering effects of oxidation and evaporation. He was

  practical experience that the latter cup is ordinarily

  consumed before it has been appreciably altered. The above results in the fact that it is necessary to place the open bottom end of the spout pipe at such a height, above the bottom of the pot, that

  the whole of this open lower end remains complete.

  immersed for remaining coffee levels which are generally in the range of 1/6 to 1/4 of the filling height of a pot of 8 to 12 full cups. This range is given to take into account abilities and shapes

  different pots, being of course that the inferior end -

  the spout line should be as low as this

* is practicable.

  Although the lid assembly and the wall of the pot

  above the coffee level behave inherently as a condenser, it is possible to further reduce this

  low vapor loss to the atmosphere by means of penetration

  by providing an additional surface on the assembly, essentially constituting a section

condenser.

  This is the idea of combining a spout and an air vent assembly, which may or may not include a condenser section, in the form of a complete structure

  in one piece, equipped with a handle for a standard coffee pot.

  which is one of the important aspects of the invention.

  If the lid assembly is to be placed on a pot after it has been filled with coffee, the means of penetration

  need only have one penetration opening

  If the lid is to be placed on the pot before it is placed under a drip coffee maker to receive coffee frankly infused with central "air-entraining means", a second air opening must be provided for - i. -_. u-u-ue-ue pdot -st rexnp- ;. It is necessary to complete a large central opening of the lid assembly in the conventional manner, this opening then being closed by a closing slide or the like, containing the restricted air penetration means. It is not the number of air openings or their mutual distance which is of decisive importance, it is rather their total surface; that is to say that their total surface must be sufficiently

  small to maintain supra-atmospheric pressure on the

  the pot, when it contains a quantity of hot coffee more than 710C for example. Indeed, there is no need to form special holes in the cover assembly if it is fitted on the open upper end of the pot so that air can be admitted, any by preventing overflow of coffee when the pot is tilted for "1% 'erser from the bottom". As an example of this

  last possibility is the use of a cover

  screwed which ensures a tight seal, but not total,

compared to the atmosphere.

  The fact that a supra-atmospheric pressure is now

  naked in a glass jar can be easily discerned when the spout is made of glass or clear plastic, because we can see the surface of the coffee, inside the spout, fluctuate to corresponding levels or higher at the level of the main mass of coffee content

in the pot.

  In summary, a quantity of hot coffee, in a coffee pot having a small diameter spouted conduit that extends upwardly from the bottom and through the open top of the pot, is substantially insulated from the atmosphere by a cover assembly which contains air penetration means whose total dimension is such that the

  coffee vapor pressure is higher than the atmospheric pressure

  pheric. Therefore, except when coffee is poured,

  the quantity of coffee is isolated from the atmosphere by a firm

  hydraulic system in the spout pipe and by means of a

  steam through the air penetrating means, which considerably reduces oxidation. Evaporation is virtually eliminated by the fact that the partial pressures across the liquid / gas interface approach the equilibrium in the pot which has been made substantially watertight. Although apparently simple retrospectively, one of the major advantages of the invention from the point of view of the reception reserved by the user is that its objectives are achieved in a structure-completewith handle, using no mobile part and not imposing any constraint

  traditional methods of serving coffee.

  The "temperature difference" aspect will now be considered

  The main factors of coffee weathering, oxidation and evaporation, occur only on the surface of the coffee, and the rates of oxidation and evaporation are one and the same. As a result, an extension of the shelf life based on the idea of "temperature difference" involves maintaining a lower temperature on the surface of the coffee surface. that the consumption temperature kept at the bottom of the

  pot, from which coffee is poured.

  The difference in temperature is maintained in a pot

  heated by the bottom, making at least the upper part

  the wall of the pot and the pouring spout in a material which has a relatively low thermal conductivity, for example a ceramic material (glass or porcelain>

  or a thick walled plastic.

  Although the convective flow inside a bottom-heated liquid volume normally tends to maintain an equal temperature throughout the liquid volume, this tendency can be corrected to some extent. measuring, in order to obtain an appreciable temperature difference between the top and the bottom of the enclosed liquid, by manufacturing the container pot in a material having a low thermal conductivity. And this is because the main part of the wall of the pot is heated mainly by conduction from the contained liquid, whose maximum temperature is typically in the range between 71 and 800C, as opposed to the fact that it is also heated to an appreciable extent by conduction through the wall of the pot, from the heat source at 190 C on which the pot is placed, for example in the case of a pot of metal and, to a lesser extent in the case of a low-walled thin-blown borosilicate glass jar, the result is that in the case of a coffee pot made of a relatively low thermal conductivity material, such as porcelain or glassware. thick walls for example, the upper part of the wall of the pot is cooler than the lower part of the wall and the bottom of the pot, placed directly on the brtleur. This results in a temperature difference of 2.8 to 8.3 C between the top level of coffee in the pot

  and the bottom of the volume of coffee, from which coffee is poured.

  The reduced surface temperature, as opposed to the higher "consumption temperature" that is maintained at the bottom of the pot from which the coffee is poured, results in a

  appreciable decrease in both oxidation and evaporation.

  as the second exponential character of the vapor pressure curve for water in the temperature range in question. The temperature is high for coffee in a pot

  is usually found to be 80 C. Coffee is

  given this temperature exhibits a vapor pressure of about 335 minutes; Ia. as opposed to a vapor pressure of about 23 l-0 nm, and since evaporation can occur only from the surface of the liquid, it is apparent that the coffee to be consumed, which is poured from the bottom of the pot, may be at a desired consumption temperature of 80 C, while its upper surface is at a lower nettenc-int temperature producing a very high vapor pressure lower, which translates into a decrease

  spectacular loss of evaporation into the atmosphere.

  In the particular example just given, the vapor pressure in a conventional pot containing coffee at 80 ° C. would be more than 50% higher than the vapor pressure of a coffee.

  maintained in accordance with the concept of "difference in temperature

  "difference" being 8.3 C between the top and the

bottom of the pot.

  Since oxidation can also occur only on the surface of the liquid and since, like most chemical reactions, the rate of oxidation is directly related to the temperature, It is clear that the oxidation is similarly reduced. The precise magnitude of the difference in temperature can be determined, among other factors, by the height and

the wall thickness of the pot.

  The particular pot which is shown in Figs. 5 to 8 annexed is made of porcelain and has, for the most part, a wall thickness of 6.35 mm which is increased locally in the vicinity of the spout, the handle attachment and the base which rests on the heating burner. A porcelain pot of similar shape, with a capacity of 168 cm 3, a maximum base diameter of 127 mm and a height of the filling level of 177.8 mm was used to collect test results. Initially, the pot was filled with coffee from an automatic drip coffee maker delivering coffee at 800C. The heater control was set to produce a maximum temperature of the 1900C heater surface and maintain the temperature of the coffee at 80C in the immediate vicinity of the pot bottom. The temperature at the top level of the coffee inside

  the pot stabilized accordingly at 740C and at the upper

  coffee inside the small diameter spout,

  at 71ÀC. This last temperature can be easily explained

  on the basis of the convective flow which is forced

  reduced in the spout of small diameter and long

  relatively large, this spout being further away from conductive heating sources

  coffee in the pot on the one hand and the warming

  on the other hand. In the test pot, a spout having a circular cross section measuring 9.52 mm in diameter was used. The additional importance of the strong temperature reduction on the coffee surface in the spout will be explained below in relation to the combination of the notions of

  "temperature difference" and "air penetration means".

  The ratio of the top and the bottom of the coffee contained in the table is due to the character of the vapor pressure curve in this temperature range.

as already indicated.

  In case of use of a lid-shaped set

  more or less classical, with a large central opening

  trale through which the steam can escape freely, the shelf life of the coffee kept under the conditions of the example just given is approximately doubled,

  according to the rate of lowering of the level by consumption.

  We get a dramatic increase in the duration

  of conservation by combining the notion of "means of penetration

  restricted air "with the notion of" difference in temperature

  in this case, loss through evaporation into the atmosphere and oxidation occurring

  from and at the level of the large coffee surface to the

  the pot are clearly limited respectively by said equilibrium approach and said vapor closure. These two alteration factors are further limited by the lower surface temperatures in the pot, when

  the latter is made of a bad thermal conductor.

  However, the most important aspect of the combination

  both of these terms refers to the higher level of coffee inside the spout. When the concept of "restricted air penetration means" is applied, the main container of coffee contained is protected against oxidation and evaporation, the small-diameter pouring spout being the only one to present a surface of coffee or the Oxidation and evaporation can occur without hindrance. The fact that this exhibition area is very small, to the point that the altering effects

  are limited enough to be considered negligent

  over a period of several hours, is the basis of the success of the concept of "means of restricted air penetration". Nevertheless, alteration occurs at this surface, although to a negligible extent compared to a conventional free-penetration pot. But even this limited alteration that occurs in the spout can be significantly reduced by the notion of "temperature difference" here exposed. Indeed, if one refers to the vapor pressure curve, one can see that the temperature difference (90C in the case of the described test) between the upper level of the coffee in the spout and the bottom of the pot increases the duration of conservation, even beyond that obtained by the notion of

  "Restricted air penetration means" applied alone.

  Due to the small size of the spout, the difference

  The temperature referred to above (80 ° C at the bottom of the pot and 71 ° C at the top of the coffee in the spout) does not give rise to a significant drop in the temperature of the coffee poured. Under test conditions, coffee being poured

  in a cup at room temperature, a constant measurement of

  cup temperatures of 73.4 ° C + 0.550 ° C, compared to cup temperature

accepted from 740C.

  As will be appreciated from the foregoing, there is no significant difference in temperature between the upper and lower portions of a quantity of coffee contained in a conventional thin-walled borosilicate glass pot, as shown in FIGS. 1 to 4, and this also applies to

  the upper level of coffee in the interior vent with green beak

  fig. 1 to 4. This last point can be explained by considering that the small-diameter spout and the small volume of liquid it contains quickly reach a temperature equilibrium with the liquid that surrounds them completely, unlike the external spout. shown in figs. 5 to 8, is relatively isolated from heating by

conduction by the contained liquid.

  FIG. 1 is a vertical sectional view, some parts being shown in broken lines, of a blown borosilicate glass coffee pot to which the

  notion of "means of restricted air penetration" and which

  carries a pipe with internal spout.

  FIG. 2 is a partial view in a higher plane of

Figure 1.

  FIG. 3 is a vertical sectional view, partially

  in elevation, of a variant of the embodiment

2495920 -

shown in Figure 1.

  FIG. 4 is a top plan view of the

figure 3.

  Fig. 5 is a vertical sectional view of a porcelain coffee cup designed to maintain a temperature difference between the surface of a quantity of coffee contained and the

content of the bottom of the pot.

  Figure 6 is a top plan view of the

figure 5.

  FIG. 7 is a vertical sectional view of the pot of FIG. 5, equipped with another cover assembly for holding

  a supra-atmospheric pressure on the coffee contained.

  Figure 8 is a top plan view of the

figure 7.

  Figure 9 is a plot of the pressure curve of

steam for water.

  In Figures 1 and 2 there is shown a coffee pot, having a peripheral perimeter not perforated 12 in borosilicate glass or a similar material, its upper end open? tne.inant by a circular lip to

edge 14.

  A set 16 plastic cover comprises -

  outer and outer circumferential projections 1E, 20 spaced apart from one another, forming a closing ring 22 directed downwards, adapted to snap fit on the rim lip 14 of the pot. A pouring spout 24, closed in one piece, extends from the vicinity of the bottom of the pot 10 to the upper surface of the cover assembly 16 and has reinforcing ribs 26, a central filling opening 28 in the cover assembly 16 can be closed at will by a slide 30 mounted in guide supports 32 formed integrally with the cover assembly. In the drawer 30 is formed a small air passage opening 34 so that it is possible to pour coffeeparle pour spout 24 when the drawer 30 is closed. The cover assembly 16 is preferably manufactured by injection molding of a plastic material such as polysulfone or polycarbonate, since the temperature range of the coffee, with which the lower end of the spouting conduity will be in prolonged contact,

  varies between more than 71 ° C and about 880 ° C, because the differences

  different heaters with which the pot will be used will vary

  to an appreciable extent with regard to their calibration.

  The desired temperature range is in the immediate vicinity of 79 # 50C to give a desired temperature of cups of

the order of 73.50C.

  If necessary, the snap ring

  22 Should be interrupted to marry the upper extremity

  upper 38 of the handle assembly 40 if it covers a portion of the upper lip rim 14 in the immediate vicinity of the handle, provided that the assembly is substantially sealed. It should be remembered that it does not matter whether such an interruption of the snap-fastening crown 22 (not shown) results in a leaky assembly of a

  side or other of the upper end 38 of the whole

  handle, because it is the total area of air passage that is important. Indeed, if a perfectly sealed seal is not established on one side or the other of the handle assembly, the unsealed portion is nevertheless very small, so that its surface of "air passage ", considered with the air passage surface of the central air passage opening 34, is still the" restricted air penetration means "which will maintain a supra-atmospheric pressure in the container in the presence of a amount of coffee maintained above 71 ° C. It is important that the seal on the spout side of the pot is intact, so that coffee does not "leak" over

  the lip when poured through the spout.

  The handle assembly 40 and the method of attachment of its steel strip 42 are quite conventional and play no role in the present invention, beyond the fact that such

  set-handle is needed in any form.

  For the use of the model shown in Figs. 1 and 2, the assemblycover 16 is adapted to the pot 10 and the drawer 30 is placed in the open position of the

  Fig. 2. The Dot is then placed under a self-service coffee maker.

  drip flow and coffee frankly

  infused flows through the central filling opening 28.

  When the pot is filled, the drawer 30 is placed in the position

  closed. With a conventional heater that maintains the stability and stability of the engine, the hydraulic system closes the baffle. pourer 24 and the pinhole passage 34 which admits a loss of vapor in the atmosphere much lower than the formation of steam vaporization through the liquid interface /

  gas. This results in the establishment of a sup-

  atmospheric inside the pot, blocking the penetration

  air through the means of air penetration, and the

  conditions close to equilibrium

  liquid / gas side, which virtually eliminates the loss by evaporation into the atmosphere. The oxidizing effects of the relatively negligible volume of air introduced by the means of

  air penetration produces little oxidative

  during a period of 4 to 6 hours, depending on the rhythm

  drop in consumption level.

  Instead of providing a central opening of

  wise and a drawer, the upper surface of the entire-cover

  Key 16 may be non-pierced, except for an air entry opening. In such a case, the cover assembly would

  set up after the pot has been filled.

  The embodiment shown in FIGS. 3 and 4 illustrates an application of the invention to a different style coffee pot, with a lid assembly whose surface

  is increased, the means of air penetration also serving

  Filling opening aperture In FIG. 3 is shown a coffee pot 44 of thin glass, the open upper end has a

cylindrical neck 46.

  A cover assembly 48 made of a deformed material

  mable such as a plastics material or the like, comprises a cylindrical skirt 50 dimensioned to fit in the opening of the neck 46, with respect to which it is sealed by deformable sealing rings 52, 54,

  respectively in contact with the upper and lower edges

  the opening of the cylindrical neck. The lid assembly includes a convolutional condenser section 56 which converts centrally into a well 58, at the lower end of which is formed a combined flow opening 60

  drip and air penetration. An additional opening

  The air inlet 62 is formed at an external point.

  the opposite side to the pouring side of the pot. A small diameter spout conduit 64 extends from the vicinity of the bottom of the pot 44 to the upper surface of the lid assembly 48. The spout conduit 64 may have an inside diameter of 9.52 mm and it is formed in one piece with the cover assembly 48, for example by blow molding or the like, or it can be manufactured separately and fixed to the cover assembly in a subsequent operation. In either case, the cover assembly 48, which includes the condenser section 56 and the spout conduit 64, is a complete assembly with a handle that can be placed in

  the opening of the neck 46 of a conventional shaped pot.

  When used with a drip-flow automatic coffee machine, the lid assembly 48 can be put into place on the pot 44 before the coffee has passed. The frankly brewed coffee then flows into the well 58 and into the pot through the drip opening 60. The air passage hole 62 allows the displaced air to escape during the filling of the pot. beyond the open bottom end

of the spout 64.

* The total area of the air passage openings 60 and

  62 is chosen small enough that a supra-atmospheric pressure

  The amount of coffee intended to be contained therein is maintained at 71 ° C at least. With the usual coffee holding temperature of 79.50C, the air passage opening 60 can have a diameter of 1.58mm.

  and the air passage opening 62 has a diameter of 0.39 mm.

  When the coffee should not be introduced into the pot through the opening 60 of the well, it is desirable that it be even smaller, in order to further reduce the escape of the well.

vapor in the atmosphere.

  The exclusive application of the "temperature difference" approach to extend the shelf life of coffee is illustrated in figs. 5 and 6. In these figures is shown

  a coffee pot 100 provided with an external spout 102 in communi-

  with the inside of the pot by an opening 104 immediately

  adjacent to a thickened bottom 106 to be placed on a heater (not shown). The pot and the spout are

  made of relatively thick-walled porcelain and open

  The lower spout 104 of the spout is completely contained

  in the lower sixth of the filling height of the pot.

  A cover assembly 108, having a large central aperture 110, is sealed at its periphery with respect to the upper end 112 of the pot 100 by means of a gasket.

deformable 114.

  For use, freshly brewed coffee is introduced

  in the pot, for example by dripping from an automatic coffee machine, through the central opening 110 of the assembly 108. The bottom 106 of the pot resting on a

  conventional thermostat-controlled heater, whose tempera-

  maximum surface area varies from 177 to 2180C depending on the manufacturer, the temperature of this coffee in the immediate vicinity of

  background typically stabilizes at a "consumer temperature"

  In the range of 710C to 820C, the surface temperature of the coffee contained in the pot is lower than the temperature of consumption at the bottom of the pot, because of the poor thermal conductivity of the pot porcelain. , 7 to 8.30C, depending on the temperature of the heater, the volume of the coffee contained, the height and the wall thickness of the

  pot among other factors. In any case, a difference in temperature

  The structure is inherently existent in such a pot heated by the bottom and the difference is even greater at the surface of the coffee in the spout. Referring to the vapor pressure curve for water (Fig. 9), it can be seen that the exponential nature of the curve in the question range converts even a small temperature difference into a large variation in temperature. vapor pressure. Since the coffee is poured from the bottom of the pot where the temperature of consumption is maintained, the lower temperature at the surface has no disadvantage from the point of view of serving hot coffee, but offers the advantage of greatly reduced evaporation loss, because the vapor pressure is lower. The lower temperature on the surface

  also results in a lower rate of oxidation.

  It is understood that the pot 100 of figs. 5 and 6 is completely in communication with the atmosphere by the great

  central opening 110, so that the oxidation and evapo-

  may occur freely from each other at and from the upper surface of the coffee contained in the

  pot. It is about the reduced rate of these two processes of alteration.

  depending on the lower temperature at the surface, compared to the higher consumption temperature which is necessarily maintained at the bottom of the pot, which is relied upon to extend the duration of consumption. The peripheral seal 114 between the assembly and the container is intended to prevent leakage over the top wall of the container.

  pot while pouring coffee through the spout 102.

  The pot 120 of FIGS. 7 and 8 does not differ from pot 100 of the

  Fig. 5 that by the form of construction of the assembly-cover

  122. The cover assembly 122 includes a cover member 124 which is sealed at its periphery relative to the

  upper wall 126 of the pot, by a sealing ring 128.

  The cover member 124 is in a bowl, so as to form a well portion 130, and is blind, except for a small central air passage hole 132, of the order of 1.58. 1 mm diameter, and an additional air passage pinhole 134. At its upper end, the cover member 124 is covered by a removable decorative top 136, pierced with a

large central opening 138.

  For use, the coffee is introduced into the well portion 130 through the central opening 138, and from there it flows into the pot 120 through the central through opening 132. The pinhole 134 allows movement of air from the pot 120 from the moment the coffee level rises above the lower opening 140 of the spout. The coffee pot 120 being filled and the coffee immediately adjacent to the bottom being kept at the temperature of consumption, the pressure of

  reduced vapor resulting from the notion of temperature difference

  described above results in a higher pressure than

  above the level of the contained coffee, due to the

  restricted character of the air penetrating means 132 and 134.

  It should be noted that this effect can be reinforced and that the shelf life can be prolonged if only one of the following is provided: in which case the set 12a should be adapted to the pot after it has been filled with coffee. In either case, the mass of coffee contained is isolated from the atmosphere, when the pot is standing outside the moments when the coffee is poured, by a hydraulic closure inside the spout and by a closure of steam through the means of restricted penetration of air. Thus, the oxidation is strongly

  limited. Similarly, partial pressures across the

  liquid / gas face approaching equilibrium, which limits strong-

loss by evaporation.

  The explanation of the limitation of oxidation and evaporation by the notion of means of restricted penetration of air is here the same as that which was given previously

about figs. 1 to 4.

  Although the combination of the notions of "temperature difference" and "hoyens of restricted air penetration"

  result in an extension of the net retention period

  more important than the exclusive application of any of these notions, the most important aspect of the combination of these concepts is, it seems, the fact that the spout is relatively isolated, thermally, from

  heating sources (coffee content and reheater). The explanation

  This seems to be the following: since the higher level of coffee in the spout is the only surface, although small, where oxidation and evaporation occur.

  produce without obstacles, it is clear that in the combination of

  sound, if the temperature at the top level in the spout

  is significantly lower than the consumption temperature required

  If it is maintained, oxidation and evaporation from this surface will be reduced. Since the reduction in temperature is even more pronounced than at the surface of the coffee contained in the pot, because of the relatively greater distance, and since the temperature ganme concerned is situated on an exponential part of the vapor pressure curve, we can see how important it is to combine these notions. Indeed, in the thin-walled pots of FIGS. 1 to 4, the temperature at the upper level of the coffee in the spout is almost the same as that of the coffee contained in the pot that surrounds this duct, which in turn is practically the same.temperature at the bottom of the pot, because it is made of thin-walled borosilicate glass, so that the shelf life with this pot (Figures 1 to 4) is less than that of the embodiment of figs . 7 and 8, applying the two concepts of "means of restricted air penetration" and

"temperature difference".

  Although the difference in temperature that can be obtained is a little less marked, the notion of difference in

  temperature can be put into practice with a construction pot

  composite, if at least the upper part of the pot wall is made of a material with low thermal conductivity. For example, a composite pot having a stainless steel bottom joined to a plastic top wall,

  for example polysulfone, and an external spout.

R E V IN D I C A T IO N S

  1. Coffee container open at its upper end and intended to contain a quantity of hot coffee whose vapor pressure is greater than atmospheric pressure, with a

  cover assembly (16; 48) which has a vertically

  24, 64) and which closes the upper end of the container (10; 44), characterized in that the spouted conduit (24; 64) extends from the vicinity of the bottom of the container (10; 44). to the upper end thereof, such that coffee can be poured through the spouted conduit from the bottom of the container, and that means (16, 34; 48, 60, 62 ) comprising this cover assembly (16; 48) are:

  intended to allow air to enter the container and to

  hold a supra-atmospheric pressure in this one in the presence

a quantity of hot coffee.

  2. Container according to claim 1, characterized in that the assembly cover (16; 48) is contained substantially

  entirely within the profile of the container (10; 44).

  3. A container according to claim 1, characterized in that the open bottom end of the pouring spout (24; 64) is contained entirely in the lower quarter of the

container (10; 44).

  4. Coffee container for containing a quantity of hot coffee having a vapor pressure above atmospheric pressure, said coffee container (10; 44) having a peripheral wall (12) without piercing and an open upper end characterized by the combination of means (16, 24, 34; 48, 60, 62, 64) for maintaining a supraatmospheric pressure within the vessel (10; 44) in the presence of a quantity of hot coffee and for allowing pour this coffee from the bottom of the container, to the top of the top, open

of it.

  5. A container according to claim 4, characterized in that said means comprise a cover assembly (16; 48) which substantially closes the open top of the container (10; 44) with restricted passage means. air (34; 60, 62) in this cover assembly and a conduit to

  spout (24; 64), sealingly attached to the

  cover and extending from the vicinity of the bottom of the container

  to the upper surface of the cover assembly.

  6. A container according to claim 5, characterized in that the assemblycover (48) comprises a condenser section (56). 7. A process for reducing the oxidation and evaporation of coffee in a spout-type container (10; 44) (24; 64) according to claim 1, characterized in that it comprises introducing a quantity of coffee in the container at

  coffee (10; 44), to maintain this amount of coffee at a

  higher than 710C, to maintain a pressure above

  atmospheric inside the container, and to pour the coffee from the immediate vicinity of the bottom of = said amount of coffee. 8.- that the coffee method according to claim 7, characterized in that it is poured by a spout (24; 64) and in that.the lower open end of the spout is contained

  entirely in the lower quarter of the container (10; 44).

  A process for reducing the oxidation and evaporation of coffee in a spout-type container according to claim 7, characterized by lowering the level of coffee in the container (10; ) by pouring

  periodically one or more cups of coffee from the

  Immediately swim the bottom of said amount of coffee, and to maintain said supra-atmospheric pressure following each intake of coffee does not remain more than two cups of inside the periodic container, until

coffee in the container.