WO1993025132A1

WO1993025132A1 - Yoghurt maker

Info

Publication number: WO1993025132A1
Application number: PCT/NZ1993/000049
Authority: WO
Inventors: Leonard Douglas Light
Original assignee: Leonard Douglas Light
Priority date: 1992-06-16
Filing date: 1993-06-16
Publication date: 1993-12-23
Also published as: AU4361293A

Abstract

Apparatus for making a fermented food product such as yoghurt. The apparatus comprises an insulated chamber and a baffle having a moderate thermal conductivity. In use, the baffle is placed in the chamber and hot water is poured into the chamber, covering the baffle. A container containing a yoghurt producing mixture is placed in the chamber above the baffle. The hot water provides a heat source necessary for yoghurt production and the baffle member provides a controlled transfer of heat energy from the water to the container.

Description

"YOGHURT MAKER"

TECHNICAL FIELD This invention relates to apparatus for producing a fermented food product and has been devised particularly though not solely for use in producing a fermented milk food product such as yoghurt in a domestic environment

BACKGROUND ART Fermented food products such as yoghurt can be made in a domestic (that is a home) environment by mixing milk powder with water and a bacterial culture and maintaining the mixture at a required temperature for a period of time.

French patent specification No. 837305 discloses the use of a hot liquid such as boiling water to provide a source of heat to maintain a mixture such as that described above at the required temperature. The hot liquid is placed in a container and a further container containing the mixture is placed over the liquid container.

Similar constructions are described in French patent specification No. 868215 and U.S. patent specification No. 4,163,472. French patent specification Nos. 1023749, 1089213 and 1302517 disclose a container for containing a mixture such as that described above, the container having a closed chamber or the like in the base or walls in which a hot liquid may be placed for providing the source of heat

British patent specification No. 242174 discloses apparatus for containing a hot liquid which can be placed around a container containing a mixture such as that described above, the outer container providing the heat source for maintaining the mixture at the required temperature.

The apparatus described in the above specifications does not effectively provide for the controlled release of heat from the heat source to the mixtiire. In apparatus such as that disclosed above, heat from a source such as boiling water is released too quickly to the mixture, so that the temperature of the mixture is too high for an initial period, following which a temperature required for the effective production of yoghurt is not sustained.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide apparatus for producing fermented milk food which will at least go some way toward overcoming the above disadvantages or which will at least provide the public with a useful choice.

Accordingly, in one aspect the invention consists in apparatus for producing a fermented food comprising a chamber having a base and walls defining a mouth of the chamber, and a baffle member having a moderate thermal conductivity, the walls having an inner surface constructed and arranged so that the baffle member is adapted to be placed in the container in contact with the inner surface and located between the base and the mouth thereby defining a cavity between the baffle member and the chamber mouth which in use receives a container for storing the food to be fermented. In a further aspect the invention consists in a baffle member for a chamber for producing a fermented food, the chamber having a base and walls defining a mouth of the chamber and an inner surface constructed and arranged to receive the baffle, the baffle member comprising a web of substantially disc form having a peripheral edge being adapted to contact the inner surface and having an aperture therein; a first flange dependent from the edges of the aperture, the first flange extending in a direction substantially perpendicular to the plane of the web.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

Figure 1 is an elevation in cross section of apparatus for producing a fermented milk food in accordance with the present invention, and Figure 2 is a plan view of a baffle member in accordance with the present invention.

BEST MODES(S) FOR CARRYING OUT THE INVENTION Fermented food products such as yoghurt may be made in a domestic (that is a home) environment by mixing milk powder with water and a bacterial culture and maintaining the mixture at a temperature of 40°C for example for four to six hours. The apparatus of the present invention allows such a mixture to be maintained at a temperature within the temperature range required for producing yoghurt and maintains the temperature of the πiixture within the required temperature range for a sufficient period of time to produce yoghurt.

Referring to Figure 1, a chamber generally referenced 1 has a base 2 and outer walls 4 constructed from a material such as a moulded plastics material. The chamber also has an inner surface 6 which is separated from the outer walls 4 by a space 8 which may contain air, or a material having good thermal insulation properties.

A closure 10 is also provided and adapted to engage with the mouth 12 of the chamber. The closure 10 has outer walls 14 and inner walls 16 which are also separated by a space 18 which contains, for example, a material having good thermal insulation properties.

The inner walls 6 of the chamber have a first shoulder 20 formed therein which supports a baffle member generally referenced 22. The baffle member has a web portion 24 of substantially disc form having a central aperture 26 therein. The edges of the central aperture 26 have first flange 28 dependent therefrom. The peripheral edges of web 24 have a second flange 30 dependent therefrom. Both the first flange and second flange are preferably provided on both sides, that is, the upper and the lower side (Figure 1) of the web member 24 and are provided continuously about the circumference of the peripheral edges of the web member and the edges of the central aperture. A second shoulder 32 is also provided on the inner walls 6.

Referring to Figure 2, the baffle member 22 is shown in plan view, and appears as shown in Figure 2 when viewed from above or below. In use, the user removes closure 10 of the chamber and with the baffle present within the chamber as shown in Figure 1, the user pours a hot substance, preferably boiling water into the chamber up to a level marked above the upper edges of flange 28 of baffle 22 to provide a source of heat A container or jar containing a sachet of milk powder and the required cultures of yoghurt producing bacteria and water is placed in the chamber above baffle 22 The jar (not shown) may rest on upper edges of flange 30 or may rest on shoulder 32 such that it is in thermal contact with the baffle. The closure 10 is then placed over the mouth of the chamber and the chamber is left for the 4 to 6 hours usually required for making yoghurt The yoghurt is produced by raising the temperature of the mixture within the jar to approximately 40°C and this approximate temperature is required to be maintained for a majority of the time required to produce the yoghurt The construction of baffle member 22 assists in the effective production of yoghurt from the mixture in the jar container by assisting in keeping the mixture within the required temperature range for the required period of time. Initially the heat in the water above the baffle is supplied to the jar to raise the temperature of the yoghurt mix. The hot water beneath the baffle 22 acts as a reservoir of heat and slowly releases heat up into the jar to balance the heat loses from the apparatus. The flange 34 of the central aperture 26 of the baffle has its edges extending below the central web 36. The distance which the flange 34 extends below the central web may be 10mm for example. Flange 34 of baffle member 22 traps air under the baffle after water has been introduced to the container and the air slows the release of heat into the jar, so preventing the temperature in the jar from rising to too great a temperature within the first few hours of the yoghurt producing process. Thus the baffle provides a member having a moderate thermal conductivity which allows a gradual or controlled release of heat from the source of heat in the chamber to the container. The baffle construction is desirable for the effective production of yoghurt, particularly when the temperature of the surrounding environment is relatively warm, for example during summer in temperate climates.

Claims

CLAIMS:

1. Apparatus for producing a fermented food comprising a chamber having a base and walls defining a mouth of said chamber, and a baffle member having a moderate thermal conductivity, said walls having an inner surface constructed and arranged so that said baffle member is adapted to be placed in said container in contact with said inner surface and located between said base and said mouth thereby defining a cavity between said baffle member and said chamber mouth which in use receives a container for storing the food to be fermented.

2. Apparatus as claimed in claim 1 wherein a shoulder is provided on said inner surface for supporting said baffle member.

3. Apparatus as claimed in claim 1 or claim 2 wherein said walls include outer walls, which outer walls are spaced away from said inner surface to thermally insulate said outer walls from said inner surface.

4. Apparatus as claimed in any one of the preceding claims wherein a closure is provided for placement over said mouth.

5. Apparatus as claimed in any one of the preceding claims wherein said baffle member comprises a web of substantially disc form having a peripheral edge being adapted to contact said inner surface, and having an aperture therein; and a first flange dependent from the edges of said aperture extending in a direction substantially perpendicular to the plane of said web.

6. Apparatus as claimed in claim 5 wherein said peripheral edge has a second flange dependent therefrom, said second flange extending in a direction substantially perpendicular to the plane of said web.

7. Apparatus for producing a fermented food substantially as herein described with reference to and as illustrated by the accompanying drawings.

8. A baffle member for a chamber for producing a fermented food, said chamber having a base and walls defining a mouth of said chamber and an inner surface constructed and arranged to receive said baffle, said baffle member comprising a web of substantially disc form having a peripheral edge being adapted to contact said inner surface and having an aperture therein; a first flange dependent from the edges of said aperture, the first flange extending in a direction substantially perpendicular to the plane of said web.

9. A baffle member as claimed in claim 8 wherein said peripheral edge has a second flange dependent therefrom, said second flange extending in a direction substantially perpendicular to the plane of said web.

10. A baffle member as claimed in claim 9 wherein said first and second flanges extend either side of said baffle member in a direction substantially perpendicular to the plane of said webs.

11. A baffle member substantially as herein described with reference to and as illustrated by the accompanying drawings.