This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
The cardamoms, the ripe fruits of Elettaria car-damomam Mat., which grow and are extensively cultivated in Hindostan and on the coast of Malabar, contain from three to five per cent, volatile oil, which is employed sometimes in compound flavors.
This may be prepared by macerating one pound of powdered cardamoms in five pints of diluted alcohol and filtering. The United States Pharmacopoeia recommends moistening the powder and packing in a percolator, and exhaust afterwards by percolation.