In this guide you will find out how to dry walnuts and store them correctly. We also give tips on what to do about mold on walnuts.
A walnut tree can bear up to 130 kilograms of fruit. Harvest time is eagerly awaited. There's nothing wrong with trying a fresh nut straight from the tree. However, fresh nuts only keep for a few days. It must be dried before storage. Below you can read how walnuts can be dried and thus preserved for a longer period of time.
Why do walnuts need to be dried?
Walnuts are not harvested directly from the tree. When the fruit is ripe, its green outer shell bursts open and the nuts fall to the ground. This usually happens from September and can extend into October. Then there is a lot to do and the floor should be checked daily for fresh nuts.
If the nut shells absorb moisture from the ground, mold quickly develops. If the fruit is not dried before eating, the entire harvest can spoil if the mold is allowed to spread unchecked.
Mold is difficult to identify at first glance, and it is particularly hard to spot on closed nuts. Moldy areas are usually found where the nut is opened. If the light brown shell has a dark discoloration in these areas, this can be an indication of mold.
Note: Check collected walnuts for mold before drying.
If large quantities of walnuts are harvested and are to be preserved over a longer period of time, professional drying is necessary. If the drying is neglected, walnut kernels will begin to mold and become inedible after just a few days.
When it comes to drying walnuts, time and patience are required. Under no circumstances should you try to dry the nuts in the oven or even in the tumble dryer. The temperatures in these devices are much too high. The nuts would go rancid and lose their distinctive flavor.
Tip: Frozen walnuts are not suitable for subsequent drying and should be dried immediately after thawingbe further processed.
Prepare walnuts for drying
After harvesting, the walnuts are first prepared for drying. The first thing to do is to completely separate the green fruit husk from the brown nut shell. If you reach your limits with your fingers, use a stiff brush to help. The green shells begin to rot quickly - the entire nut is endangered by the progressive rotting process.
Note: It is recommended to wear gloves and protective clothing. The nutshell secretes tannins that leave unsightly stains that cannot be removed from clothing.
Preparation is about cleaning and sorting the nuts.
| Operation | Explanation |
|---|---|
| Clean walnuts | • use no water if possible • clean the nuts with a brush • clean with heavy soiling wet but without pressure • dry the nuts well |
| Sort walnuts | • Only dry ripe and undamaged walnuts • Sort out nuts with damaged shells and black spots |
It is important to pick up the nuts from the ground every day. The risk of mold growth is particularly high in rainy weather.
What should be considered when drying walnuts?
Best results are obtained if the walnuts are dried indoors at room temperature. Drying directly on the heater is not advisable due to the high heat generated. On the other hand, the nuts can be laid out to dry in the attic, in the house entrance or in the boiler room without hesitation.
Drying walnuts - step by step
- Find the right place
Fruit crates have proven useful for drying nuts. These are laid out with several layers of newspaper. The nuts are then sorted into the boxes with sufficient spacing. Simple wooden frames covered with a grid are also suitable for drying walnuts.
- Make sure the temperature is right
As mentioned earlier, walnuts dry best at room temperature. Overheated premises are less suitable for this. Temperatures around 20 degrees are ideal.
- Create enough space
Make sure there are enough drying facilities, because walnuts must not be stacked in the fruit box or on the grid. So that an even drying can be achieved and theIf moisture does not accumulate, the nuts must not touch each other.
- Have patience - drying takes time
It takes four to six weeks until the walnuts are completely dry and can be stored. The nuts must be checked regularly. If the nut shells open during drying, the respective nut must be disposed of.
If you can crack the nutshell open, drying is complete. The core should appear dry and brittle. If the consistency of the core is more reminiscent of rubber, the nuts have to dry for a while longer.
Tip: Turning and turning the nuts frequently prevents mold from forming and ensures an even drying process.
Tip: If the walnuts have lost about half their mass, the drying was successful.
Drying walnuts outdoors - is that possible?
Harvest time falls in autumn and thus in a time with a rather unstable climate and a lot of humidity. On warm days, however, there is nothing wrong with drying the walnuts outdoors. If the thermometer rises above 20 degrees, there is a risk that the nuts will go rancid. The walnuts should also not be left outside overnight. There is a risk of mold due to the increased humidity. Furthermore, squirrels and other small animals are looking for food supplies for the coming winter these days.
Drying walnuts in the dehydrator
You can speed up the drying process by using a food dehydrator. The devices work with a low heat development. Therefore there is no risk of the nuts going rancid and spoiling.
Drying in the dehydrator - step by step
- Arrange walnuts on the grid of the dehydrator
- Set lowest operating temperature
- Place grid in device
- Close Dehydrator
The drying time varies depending on the device type. However, you have to be prepared for a drying time of six to eight hours. For smaller amounts of walnuts, the dehydrator is definitely an option. A large harvest can be dried more efficiently and in a more environmentally friendly way in fruit crates or on racks.
Store walnuts properly after drying
Before storing, check whether all the nuts are really completely dry. If mold forms on a nut during drying, it quickly spreads to the other fruits. The dried nuts are placed in a potato sack or in an onion netfilled and stored in a dry, cool and dark place. Hanging storage is preferable. If the walnuts are stored properly, they will keep for up to two years.