VANILLA CURING

The vanilla orchid and the mature vanilla bean have no aroma; it is the curing process that develops the characteristic flavor of vanilla beans. Vanilla beans left on the vine will cure naturally, but the pod splits, loses contents, and ultimately decreases in flavor and value. The Mexican Indians developed the original, very labor intensive process for curing green vanilla beans.French made slight modifications to this original process, and this Bourbon process is generally practiced in the Madagascar and Comoros Islands today. Other modifications are practiced in Indonesia.

No geographical source of vanilla beans strictly employs one method of curing and many parts of the process are interchanged (mixed and matched). The curing operation is not a regulated, largescale, sophisticated procedure. It is crude, nonhygienic, subject to personal modifications, and is practiced by individual small farmers up to larger scale curer-exporters. Any given shipment of cured beans may represent the composite
curing operations of dozens of individual producers. During the curing process, each bean is individually handled and inspected at least a dozen times.

All curing methods involve four basic phases:

1. Wilting or killing of the beans, which stops the natural respiratory metabolism and vegetative life of the pod . The specific technique used to kill the beans will affect subsequent vanillin contents. After wilting, the beans may have begun to turn chocolate brown in color.

 2. Sweating the wilted beans until they are flexible in the hand and can be easily wrapped around the finger. This step involves a fairly rapid dehydration and slow fermentation. The characteristic flavor compounds develop here. Key enzymatic and nonenzymatic reactions occur during this phase forming sugars, phenols, quinones, pigments, vanillin and other aromatic compounds. After sweating, the beans are deep chocolate brown. 

3. Drying of the sweated beans very slowly at low temperature to 20-25% finished moisture. Beans should still be flexible; over-drying, or too rapid drying, reduces flavor quality and value.

4. Conditioning of the dried beans in closed boxes for a few months, where they finish the development of their characteristic fragrance. Unless moldy, beans can be kept indefinitely in this state.