Part 3: Curing the Pods into Vanilla
Now that we had beans growing on the vines, we needed to know how to make them into vanilla. In our research, we found there were a small number of articles and publications discussing ways to cure the pods, but they were all either descriptions of the traditional “bourbon” method or methods suitable for industrial-scale curing. Interesting information, to be sure, but none of it was something we could do exactly as described.
Hand Curing the Beans at Home
When it came time to cure the beans from our first harvest, we looked at several curing methods. The bourbon method is slow and laborious, but the quality of it’s results are well-known and it’s an accepted standard. Several alternative methods have been developed, but the bourbon method is preferred, especially for the whole-bean trade.
The problem with the bourbon method is that I didn’t think it would work here due to the climate. The vanilla harvest season is February-April and Kauai tends to be cool and wet at that time of year. The Bourbon method calls for periods of outdoor drying to raise the temperature of the beans then they are packed into insulating blankets and into a box where they “sweat.” This sweating process is the most important part of the curing process in developing the full aroma and flavor of vanilla.
This isn’t going to work on Kauai, it’s really just not warm enough, and certainly not dry enough. Our solution is to use an insulated box with hot water bottles to keep it warm while the beans are sweating. For the drying, the beans are placed under cover in the open air. I have a drying rack on the roof that I use for this purpose. The roof is a good location for this because at night, moisture comes up from the ground, so being far away from the ground gives you lower humidity. It’s also further away from critters, which normally are not interested in vanilla, but still you don’t want them around where you’re trying to cure the vanilla.
After several years of experimentation and experience, we’ve developed what we think is the best way of curing the vanilla pods we grow here.
Our process is simple and not too different from how it is practiced throughout the Pacific where vanilla is grown.
First, we pick the beans at the peak of ripeness: this is critical because the last few days of ripening brings a big increase the the presence of glucovanillins, which are the precursors to vanillin and other aromatic phytochemicals. You want this to be at it’s maximum, but before the pod begins to open. The beans cure up better before they have opened, and the quality standard for Grade A beans requires they not be split.
Next, the beans are scalded in hot water to stop the development of the pod. If you didn’t do this, the pod would continue to ripen and split as you try to cure it. The scalding also opens up the cell walls in the pod so that the needed enzymes will be released and the hydrolysis can begin. Hydrolysis is the chemical process that develops the vanillin and other aromatics in the bean.
Once the beans have been scalded, they are wrapped in plastic and placed in the warm sweating box. They sweat like this for 48 hours, and then they are brought out for a couple of hours to dry down a little. The drying needs to take place very slowly so the hydrolysis has time to do its work, but not so slowly that the pods begin to rot. It’s often said that this curing process is a kind of fermentation, but that is not strictly true: it is an enzymatic process. There are no inoculants used, nor is an active culture of any kind encouraged to grow during the curing process. Because of this, other organisms can take up residence, so lowering the moisture level helps keep that from happening.
The sweating takes place over a 15-day period, during which the beans are moved twice a day: from the box to the drying rack and back. That’s a lot of labor when you think about this happening every day for 3 months: it’s a continuous process because we are bringing in harvests 2 or 3 times a week as the pods ripen.
After the sweating period, the pods are put out to air dry until they reach the target moisture level. This can take anywhere from 10 days to 6 weeks for a large, fat pod. The target moisture level is 30% or 20%, depending on whether it is going to be a grade A bean or grade B. You know beforehand because the grade A beans are the largest, most intact beans with no deformities. We also generate an “extract” grade bean that is not sold in whole form, but is just made into extract. These are deeply split or misshapen beans that couldn’t be sold otherwise.
After air drying, the beans are vacuum-sealed and stored for at least 2 months for conditioning. After that, they are repackaged for sale or made into extract.
In the next chapter, I will talk a little about how vanilla culture is practiced here. We have our own take on that, too, and there’s good and bad.