An apparatus for manufacturing food tablets for hot beverage brewing, said apparatus comprising: a reservoir, configured for feeding a loose infusible food product; grinding means, configured for grinding the loose infusible food product to obtain grounds with a predetermined particle size; moistening means, configured for moistening the grounds to impart a predetermined moisture content thereto, to obtain wetted grounds; mixing and homogenizing means, configured for mixing and homogenizing the wetted grounds to obtain a homogenized mixture; weighing means, configured for weighing the homogenized mixture to obtain a dose having a predetermined weight; forming means, configured for forming the dose into a tablet having a predetermined volume; irradiating means, configured for irradiating the tablet with a beam of electromagnetic waves to overheat particles of the homogenized mixture of said dose to partial baking and/or sintering, and impart relative compactness and self-supporting ability thereto without requiring an enclosure; wherein control means are provided, configured for controlling the grinding means, the moistening means, the mixing and homogenizing means, the weighing means, the forming means and the irradiating means to control particle size, moisture content, homogeneity, weight, volume and compactness parameters of the tablet, to thereby change water permeability of a finished food tablet to be obtained according to said parameters, wherein the irradiating means comprise an electromagnetic wave generator connected to an antenna within an applicator via a coaxial cable, said electromagnetic wave generator being adapted to generate an AC electromagnetic field with an oscillation frequency in the microwave range, from 0.5 to 3 GHz, and wherein: - the forming means comprise at least one pocket adapted to be placed below the weighing means for temporarily collecting said dose; - said applicator comprises a stationary upper portion defining an inner irradiation cavity and a movable lower portion, which is defined by said at least one pocket, said antenna being located in said inner irradiation cavity, and - said applicator is equipped with a regulator element, which is adapted to vary and calibrate a resonance frequency of said inner irradiation cavity to adapt said resonance frequency to an emission frequency of said electromagnetic wave generator. a reservoir, configured for feeding a loose infusible food product; grinding means, configured for grinding the loose infusible food product to obtain grounds with a predetermined particle size; moistening means, configured for moistening the grounds to impart a predetermined moisture content thereto, to obtain wetted grounds; mixing and homogenizing means, configured for mixing and homogenizing the wetted grounds to obtain a homogenized mixture; weighing means, configured for weighing the homogenized mixture to obtain a dose having a predetermined weight; forming means, configured for forming the dose into a tablet having a predetermined volume; irradiating means, configured for irradiating the tablet with a beam of electromagnetic waves to overheat particles of the homogenized mixture of said dose to partial baking and/or sintering, and impart relative compactness and self-supporting ability thereto without requiring an enclosure; wherein control means are provided, configured for controlling the grinding means, the moistening means, the mixing and homogenizing means, the weighing means, the forming means and the irradiating means to control particle size, moisture content, homogeneity, weight, volume and compactness parameters of the tablet, to thereby change water permeability of a finished food tablet to be obtained according to said parameters, wherein the irradiating means comprise an electromagnetic wave generator connected to an antenna within an applicator via a coaxial cable, said electromagnetic wave generator being adapted to generate an AC electromagnetic field with an oscillation frequency in the microwave range, from 0.5 to 3 GHz, and wherein: - the forming means comprise at least one pocket adapted to be placed below the weighing means for temporarily collecting said dose; - said applicator comprises a stationary upper portion defining an inner irradiation cavity and a movable lower portion, which is defined by said at least one pocket, said antenna being located in said inner irradiation cavity, and - said applicator is equipped with a regulator element, which is adapted to vary and calibrate a resonance frequency of said inner irradiation cavity to adapt said resonance frequency to an emission frequency of said electromagnetic wave generator. - the forming means comprise at least one pocket adapted to be placed below the weighing means for temporarily collecting said dose; - said applicator comprises a stationary upper portion defining an inner irradiation cavity and a movable lower portion, which is defined by said at least one pocket, said antenna being located in said inner irradiation cavity, and - said applicator is equipped with a regulator element, which is adapted to vary and calibrate a resonance frequency of said inner irradiation cavity to adapt said resonance frequency to an emission frequency of said electromagnetic wave generator.