I occasionally get questions from people who are growing their own vanilla and want to know the best way to cure the beans. Getting a good cure out of your beans can be a little challenging, but hopefully, this guide will make it easier.
This guide is specific to the curing method we use here on Kauai. It is adapted from the “bourbon” method used in equatorial areas. Kauai is too cool and cloudy during the curing season to rely on the sun for heating the beans, so we use electricity to maintain curing temperatures.
It is essential that vanilla be properly cured in order to obtain the desired aroma and flavor from your vanilla beans. Processing vanilla beans is a matter of supporting both the vanillin development and the slow drying of the bean in order to preserve it.
The instructions here are for vanilla planifolia beans. There are 3 types of vanilla beans: Bourbon (vanilla planifolia), Tahitian (vanilla tahitensis), and Pompona (vanilla pompona). Each type has a somewhat different curing process, although the vanillin chemistry is generally the same. Planifolia is the one most widely used for vanilla production.
Equipment You’ll Need
In order to cure your vanilla, there are a few essential pieces of equipment you’ll need.
- Big pot for killing/thawing the beans
- Freezer (if you’re freezing them)
- Food Dehydrator
- 48 qt. Cooler
- 2 Gallon Jugs
- Kitchen Towel
- Thermometer (spike or infrared thermometer for food applications)
- 1 Gallon Plastic Zipper Bags
The food dehydrator is the most substantial item here, the widely-available Excalibur is a good choice. It’s best to have one that uses a fan to circulate the air and has a temperature control.
The cooler should be one that is well-insulated with thick walls and lid. Thin, inexpensive plastic or styrofoam coolers can be used, but it’s harder to maintain the internal temperature with those. The cooler needs to be big enough for the two gallon jugs, leaving room for your curing vanilla. The common 48 qt. size works well.
The freezer is to store your ripe beans until they can be cured. If you’re blessed with a large harvest (8 ounces/25 beans or more), you can skip the freezing part, and you’ll get better results. The thermometer is needed to to monitor the temperature, and zipper bags are what you use to hold the curing beans.
Start With Ripe Vanilla Beans
One of the most important ingredients for a successful cure is to start with ripe beans. A ripe vanilla bean will be yellowing at the tip and showing the early signs of splitting, or it’s beginning to split. The photo at the top of this article shows what ripe beans look like. The yellowing should ideally be pretty dark yellow/orange, not just pale green.
The ripening is important because the vanilla flavor is derived from the sugars that develop as the bean ripens. You want maximum sugar development for two reasons: strongest flavor and the sugars act to preserve the bean once it’s cured.
Beginning the Curing Process
Ripe vanilla beans, once picked, should be cured right away. You should begin curing the beans within 24 hours of picking.
The first step is called “killing” and what it does is stop the ripening process and open the cell walls to release the enzymes and vanillin precursors. There are several ways to kill your beans, but for most hobbyist growers, freezing is very practical.
Freezing the beans works well if you’ve got a small number of vanilla plants. The beans on your plants are not going to ripen at the same time, you’ll be harvesting a few each couple of days. As each bean ripens, put them into a freezer bag in your freezer until all your beans have ripened.
By doing it this way, your many small harvests will be combined into a single batch the be cured. This will make the curing process a lot easier to manage, and get you closer to the optimal curing batch size, which is about 1 pound of green beans.
If your harvest is 8 ounces or more (about 25 beans), you can and should cure your beans immediately, skipping the freezing part.
Setting Up The Sweat
Then next stage of the curing process is called the “sweat.” This is because the beans seem to sweat out moisture, which is necessary to get the chemical reactions going.
In very simple terms, the process we are fostering here is the enzymatic breakdown of the gluco-vanillins that are present in the ripe pod into two components: vanillin and glucose. Vanillin is the flavor and aroma of vanilla and glucose is an essential natural preservative to prevent the bean rotting or molding.
When you’ve harvested all your ripened beans and they have been in the freezer for at least 24 hours, you’re ready to begin sweating.
Prepare your sweat box (the cooler) by filling the jugs with hot tap water. This will typically be about 120℉. Place them in the cooler with space between them for the vanilla. Put a rolled-up towel (one you don’t mind getting wet and possibly stained) into the gap. The sweating vanilla will go on top of the towel, which prevents it from sitting in any moisture that might collect on the bottom of the cooler.
“Killing” the Beans
To prepare the beans for curing, they must be treated to prevent them from ripening further during curing. This also fulfills the critical function of initializing the enzymatic process that develops the vanillin in the bean. Traditionally, “killing” is done in the sun or in hot water. Freezing accomplishes the same goal, while holding the beans until you are ready to take them to the next step.
For beans that were frozen, we only need to thaw and warm them.
We used to do this in the food dehydrator, but I’ve found the results are better using a hot water bath. Get a large pot of water hot, not boiling, should be about 130–150℉. Put your frozen beans into the big pot of hot water for a minute or two, just enough to get the beans warm. You want to use a big pot for this, as the frozen beans will cool the water. If there is more water, this will be less of an issue.
For fresh/not frozen beans, we keep them in the hot water bath for 2 1/2 to 3 minutes depending on the size of the bean.
Place the thawed/killed beans into a freezer bag. If you do have more than about one pound of beans, split it into two bags. Label the bag with the date, and place in the sweat box, on the towel between the hot water jugs. Keep the lid closed.
In the next part, we get into how to complete the sweating process and how to dry and age the beans…