In this post, you’ll lean how to process vanilla beans.
Post-harvest processing and curing of vanilla beans is an important part of vanilla cultivation. To get quality-cured beans, you need to use a combination of experience and sound technical know-how.
Vanilla beans are ready for harvest in six to nine months after pollination. The beans are harvested one by one when they are fully-grown and as they begin to ripen.
At this stage, beans change their colour from dark green to light green with yellow tinge. The well-ripened ready beans detach easily from the bunch just by lifting them in reverse direction whereas the immature beans are very difficult to detach.
As the green beans do not have any aroma, the processing and curing of these beens should start within a week of harvest.
The grading of the vanilla beans is done based on the size and appearance of the beans due to the high correlation between these factor and the aroma of the beans i.e. the vanillin content.
The beans are classified according to their length into three main categories. After sorting the beans are washed with fresh water to remove any dust present on the beans.
Graded beans are transferred to a bamboo basket and immersed in hot water at a temperature of 65 degrees celsius for periods varying between 4-15 minutes depending on the length and size of the beans.
The beans taken from the killing process are then kept in a wooden box lined with blanket for 24 hours, for sweating. The temperature is initially maintained at around 45 degrees. The beans attain a light brown colour and start bringing out aroma at the end of sweating process.
Later on, the beans are spread in hot sunlight (from 12 noon to 2 pm) over a wooden loft on a clean black blanket. The temperature of the beans, at this time is to rise to 55 degrees celsius. After 2 hours of sun drying, they are bundled together covered with same blanket and kept in sunlight for half to one hour so that sweating initiates there itself.
Later on, the bundles are transferred to the sweating box. This process is repeated for 2-7 days depending again on size of the beans. At the end of this period, the beans lose half of initial weight, turn to a shining dark brown colour and develop wrinkles. This process improves the aroma of the beans.
The next step involves the spreading of the beans in racks kept in well-ventilated room maintained around a temperature of 35 degrees celsius and relative humidity of 70 per cent. The duration of slow drying depends on size of beans and varied from 2-8 days to 20-35 days.
On completion of slow drying, the vanilla beans get brownish black in colour and become supple. They offer a soft leathery touch; can be rolled around finger easily and regain the shape. The moisture content at in the beans at the end of slow drying is around 30-32 per cent.