Microwave canning apparatus

Claim 1

An apparatus for use in a microwave oven for canning food products in a non-metallic jar having a mouth, comprising: a non-metallic jar having a mouth; a jar lid of non-metallic material and having sealing means for engaging the mouth of the jar and forming an airtight seal therewith under the influence of greater atmospheric pressure outside the jar than inside; and an enclosure of non-metallic material generally transparent to microwave energy enveloping said jar and said lid and comprising a base member for engaging the base of said jar and holding said jar in a predetermined position; a cover member releasably engaging said base member and enclosing at least the portions of said jar and said lid not enclosed by said base member, said cover member and said base member forming a pressure-tight seal therebetween when so engaged as to prevent the entry of gas from outside the enclosure to within the enclosure; means connected to said cover member for resiliently urging said jar lid against said jar mouth, and pressure control means communicating with the interior of said enclosure for limiting the maximum pressure within said enclosure to a predetermined amount above the ambient pressure outside said enclosure sealing the enclosure against entry of air, whereby said jar and said lid enclosing a food product and held within the enveloping enclosure may be heated within a microwave oven to form steam of the predetermined maximum pressure within the jar to sterilize the food product and venting the steam from the jar and from the enclosure, with subsequent cooling of the enclosure and the jar causing the pressure within the enclosure and outside the jar to be less than the ambient outside the enclosure and greater than the pressure in the jar, said pressure control means preventing the entry of air into said enclosure, thereby causing the venting of the steam from the jar, again, and to effect an air-tight seal between the lid and the jar when removed from the enclosure.

Claim 2

An apparatus for use in a microwave oven for canning food products in a non-metallic jar having a mouth, comprising: a non-metallic jar having a mouth; a jar lid of non-metallic material and having sealing means for engaging the mouth of the jar and forming an airtight seal therewith under the influence of greater atmospheric pressure outside the jar than inside; and an enclosure of non-metallic material generally transparent to microwave energy enveloping said jar and said lid and comprising a base member for engaging the base of said jar and holding said jar in a predetermined position; a cover member releasably engaging said base member and enclosing at least the portions of said jar and said lid not enclosed by said base member, said cover member and said base member forming a pressure-tight seal therebetween when so engaged as to prevent the entry of gas from outside the enclosure to within the enclosure; means connected to said cover member for resiliently urging said jar lid against said jar mouth, and pressure control means communicating with the interior of said enclosure for limiting the maximum pressure within said enclosure to a predetermined amount above the ambient pressure outside said enclosure sealing the enclosure against entry of air, whereby said jar and said lid enclosing a food product and held within the enveloping enclosure may be heated within a microwave oven to form steam of the predetermined maximum pressure within the jar to sterilize the food product and venting the steam from the jar and from the enclosure, with subsequent cooling of the enclosure and the jar causing the pressure within the enclosure and outside the jar to be less than the ambient outside the enclosure and greater than the pressure in the jar, said pressure control means preventing the entry of air into said enclosure, thereby causing the venting of the steam from the jar, again, and to effect an air-tight seal between the lid and the jar when removed from the enclosure.