A vanilla bean is an organic product and, like any organic product it can go bad. However, given the nature of the tough outer skin of the vanilla bean and the protective, naturally-occurring vanillin oil, it is surprisingly durable and usually salvageable.
Mold can occur as a result of temperature fluctuations and/or the inclusion of excess water or bacteria during the harvesting/drying process. Like any mold, the vanilla-bean mold feeds on oxygen and bacteria as it grows. (This is why we ship our vanilla beans in vacuum-sealed pouches with oxygen removed. It mitigates mold growth in transit.) Unlike molds on breads and cheeses, however, mold on a vanilla bean can often be removed by wiping the bean with a clean towel that has been dampened with vodka or other alcohol with a 35%+ alcohol content. Some users have used Everclear or stronger alcohols with positive results. Sometimes, the part of the bean with mold can simply be cut off.
It can often be difficult to distinguish mold from naturally occurring imperfections on the bean pod, or damage caused to the bean pod during harvesting. In addition, one bad bean does not necessarily mean that the entire batch is bad, but the entire batch should be inspected further if one bad bean is found.
Of course, if mold is present and if you are concerned about the quality of the bean, the bean should be discarded.
Here are some images of vanilla beans where the mold has grown substantially and the bean should not be used:
Vanilla beans that are vanillin rich may show other signs that are "mold-like" but not mold at all, so be cautious when throwing out your beans. You don't want to discard a perfectly-healthy bean! In fact, the presence of these abnormalities often indicates a high quality vanilla bean.
One of these occurrences is a vanillin crystal (or vanilla frost) that can form on the outside of the bean. Usually white with the appearance of a spider web, this crystal forms from the vanillin's response to temperature changes. Here is an image that we found online of an unusually-high formation of vanillin crystals so you can see in detail what it appears like. (You will notice that this vanilla bean also has a split tip, which is not unusual) This is a very healthy vanilla bean with vanilla frost and a split end:
Another occurrence that can appear like mold on a vanilla bean is "vanilla butter". This is light in color and typically found at the top or bottom of the bean. You can know that it is butter by holding it close to a heat source for a moment, and it will melt just like regular butter. You can also rub it between your fingers and it will feel like butter.
Here is an image of vanilla butter at the end of several vanilla bean pods:
Cold temperatures can also create "speckles" on the beans, or in some extreme cases, it can create a white coating (almost like a white dusting) on the bean. This may happen during shipping in the winter time. In this case the vanillin oil on the skin of the bean hardens (similar to oil hardening when left out overnight or placed in the fridge) and creates a tiny, off-white speck or a white powdery coat. The specks can be easily wiped off or just left alone. If you look closely, the speckles are often a very light brown and crystal-like. The powdery coat is the most deceiving occurrence. It's usually white and can cover a large portion of the bean. To test whether or not the powdery coat is mold, put the beans near a heat source for 15 mins or so and the powdery coat will disappear. (Mold will not disappear with heat.)
Here is a picture of vanilla beans with speckles. You have to look closely to see them:
There may be other imperfections when you examine your beans closely. There can be damage to the skin of a bean where the beans were tied into bundles by the farmers. Bundling requires the use of twine that can erode the outer skin of the beans on the outside of the bundle, as pictured below. The quality of the bean is still great.
Finally, at-home extract makers may may notice white fatty-matter appearing on their beans shortly after submersing them in alcohol. It can have the initial appearance of mold, but when you look closely you will see that it is actually the fatty vanillin oils being extracted. They will break down over time. This is typically the sign of a vanillin-rich bean that is sure to be a sweet extract.
If you ever question whether it is fat or mold, simply remove the bean from the bottle and rub the fatty matter between your fingers. Oil will be smooth like butter and will break down easily. Also remember that mold cannot grow on anything submerged in alcohol.
We personally inspect every single vanilla bean individually before it is shipped to you. We vacuum seal our vanilla beans to remove the oxygen and mitigate the occurrence of mold growth in transit. We do not rinse our beans in alcohol before shipping to you, because you would be paying for the added alcohol weight and because beans are the very best when their natural, oily surface is left undisturbed.
If you ever have questions about your beans or you are concerned about their appearance, give us a call or send us an email at firstname.lastname@example.org.
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