Effervescent composition and method of making same

A method for the manufacture of an effervescent granulate which comprises moistening particles of a crystalline edible organic acid with a solvent for said acid,

• mixing the moistened acid particles under agitation with solid, powdery calcium carbonate under conditions sufficient to produce a surface reaction between said acid crystals and said calcium carbonate and the formation of a generated calcium carbonate layer upon the crystals with the elimination of reaction water,
• adding additional crystalline organic acid and agitating the same with the surface-reacted particles to react with the generated calcium carbonate layer while the same is still damp with said reaction water,
• adding calcium carbonate or an alkali bicarbonate to the particles thus treated to react with the remaining additional crystalline organic acid,
• repeating the steps of adding crystalline organic acid and calcium carbonate or alkali bicarbonate until the desired number of additional layers has been built up and
• applying a vacuum to terminate further layer formation.

A method for the manufacture of an effervescent granulate which comprises:

• providing citric acid particles of a grain size between 50 and 700 microns,
• applying a vacuum to said particles to bring the ambient pressure to at least as low as 0.1 bar,
• moistening said particles with a mixture of alcohol and water while at a temperature of about 40.degree. C. to 60.degree. C.,
• adding calcium carbonate particles having a grain size substantially less than the grain size of said citric acid particles to form a mixture comprising a layer of calcium carbonate over said citric acid particles,
• agitating said mixture while increasing the pressure thereon to the range of 800 to 900 mbar, and
• drying said mixture at a pressure of about 10 to 20 mbar.