The cost of a walnut kernel is highly dependent on its color. Therefore, you need to know why the kernel darkens, how to avoid it and how to bleach it.
The kernel of a young, only torn walnut has a light color, after lying for several days, the kernel it darkens a little. This is a natural and normal process. After drying, the kernel takes on its permanent color.
According to the classification of the kernel by color, it is divided into very light, light, slightly dark (wheat) and dark (amber).
Reasons why walnuts are dark inside:
1. Walnut was not harvested from the ground for a long time, after it ripened and fell.
2. After harvest, the nut was not peeled or poorly peeled from the green peel. In this case, not only the kernel will be dark, but also the shell itself. The thing is that the pericarp contains tannins and juglone, they stain the nut, hands and everything with which they come in contact with a dark color.
3. In-shell walnuts were stored improperly – at too low or high temperatures, high humidity, no air circulation.
4. The walnut was dried in the sun. There is no exact opinion on this matter. Many people believe that the tannins contained in walnuts are oxidized by sunlight and the kernel turns brown.
5. If the above conditions are met correctly – the nut was harvested on time, cleaned of the pericarp, properly dried, stored according to the rules and the kernel is dark throughout the tree, most likely this is such a variety.
One of the most popular searches on Google is how to whiten walnut kernels, but there are no safe ways to whiten walnut kernels. All chemical methods that can be heard from friends or read on the Internet negatively affect not only the quality of the kernel, but also the safety of use. Agree that you would not eat a product that was soaked in lime or some kind of acid !?
How to keep the kernel light:
– Collect the nut on time.
– Do not leave the nut on the ground, especially in wet weather.
– After harvesting, do not leave the nut in the green pericarp, especially if it has already begun to separate and darken.
– Dry the nut outdoors in the shade or in a well-ventilated area, in industrial volumes – in drying chambers.
– Store the nut in a warm, dry place, in cardboard boxes or mesh bags with good air circulation.
A light kernel means that the nut is of high quality, varietal, properly stored and has a pleasant taste. Therefore, its price is higher. The taste of the dark kernel is reduced (it may even taste bitter). It is also less attractive in appearance and it is difficult to understand freshness and quality from it. Because of this, the dark core is cheaper.