The walnut makes its grand entrance in autumn. It’s delicious and very healthy. The walnut tree is also a very good house tree. Walnuts are freshest when you can harvest them from your own tree. If its green shell bursts open, the actual nut appears and heralds the harvest time.
Walnuts can spoil relatively quickly, so it is all the more important to harvest them at the right time and in the right way. The harvest season for walnuts extends from mid-September to the end of October. Early frosts cannot harm them. So there is no rush to harvest. Walnuts don’t ripen all at once and should stay on the tree until they fall on their own. Only then are they ripe, have developed their full taste and can be stored. Ripe nuts can be recognized by the fact that the outer shell tears open, becomes wrinkled and darkened. The typical walnut comes to the fore, as we know it from the trade.
Instructions for harvesting
In contrast to traditional fruit, ripe walnuts are not picked, but rather collected. If they fall on the floor, they should be picked up quickly.
- There is a risk of rot, mold and pests in the damp grass
- Harvest or pick up as daily as possible
- Keep grass under the tree as short as possible during harvest time
- On rainy days, timely picking is particularly important
- Only intact and healthy fruits are suitable for drying and storage
- Discard damaged or moldy nuts
You should definitely not knock nuts from the tree to harvest them. This leads to damage to the nuts and tree, which in turn can affect the harvest for the next year. In addition, nuts that are knocked from the tree are not yet ripe, which is noticeable in the taste. After harvesting, cleaning or cleaning follows.
Tip: If you can’t wait and want to enjoy the nuts fresh, you should remove the thin, white skin that surrounds the nut after cracking the shell, it tastes very bitter. Only later, when drying, do the bitter substances almost completely disappear.
The 1 × 1 of cleaning
Before starting to dry, it is essential to clean the nuts, without any water. That would penetrate the shell and mold the nut from the inside out. It is better to first remove the green, soft shell from the nuts to clean them. It’s relatively easy to do with your hands. Then remove the coarse remains with a brush. So they are perfectly prepared for drying.
Tip: It is advisable to wear gloves when cleaning walnuts, as the tannic acid they contain leads to brownish discolouration on the hands.
After harvesting and cleaning, drying follows. But why do nuts have to be dried at all? When walnuts are harvested, very large quantities are usually produced that cannot be used up so quickly. To keep them from spoiling, they can be made more durable by drying them. The drying process can take between four and six weeks and depends on the ambient temperature and the conditions during storage.
After that, the nuts have lost about half their original weight. The drying can take place in different ways, the oven in particular being completely unsuitable for this purpose. Even if the moisture can escape in the process, they cannot withstand the high temperatures in the oven.
In well ventilated areas
Walnuts are dried by spreading them on an air-permeable surface. These can be sheets made of cotton or linen, a wooden frame covered with mesh or wire, newspaper, gratings or low fruit stairs.
- Always dry nuts in a single layer and not lying on top of each other
- Space between the nuts ensures optimal ventilation
- The premises should be well ventilated, warm and dry
- With temperatures as constant as possible between 20 and 25 degrees
- For example in a boiler room or a heated attic
- Other rooms with similar conditions are equally suitable
- Drying neither too warm nor too cold
- If possible not warmer than 28 degrees
At temperatures above 30 degrees, the nuts could quickly become rancid due to the oil they contain. Therefore, walnut oil should only be used cold and not heated. During the entire drying period, it is best to turn the nuts daily and sort out damaged or moldy ones consistently. If necessary, the nuts can also be dried in nets. Then the nuts should be shaken well several times a day, paying particular attention to rotten or moldy nuts and sorting them out carefully.
Tip: After about four weeks you can open one or the other nut and convince yourself of the condition and degree of drying.
In some cases, nuts can also be dried outdoors, provided the weather and temperatures play along. This is especially the case on days with sunshine and at the same time moderately warm temperatures. During this time, moisture should not get on the nuts, as this would delay the drying process.
It is important that walnuts dry quickly after harvesting. If it takes too long, there is again a risk that the nuts will go moldy. Therefore, you should only go outside to dry during the day, back into the house at night and only leave the house the next day. Again, it is best to turn them several times a day so that they can dry well on all sides.
In the dehydrator
In exceptional cases, the dehydrator could be an alternative to air drying. It is important that you use a device that works with particularly low temperatures (from 15 to 20 degrees), which only a few can do. This drying method is particularly useful if you only want to dry very small quantities of nuts. You place them on the grilles of the device and set the lowest temperature. Depending on the device type, the nuts are dried within six to eight hours.
Storage and shelf life
After harvesting and drying, correct storage is essential. Here, too, temperature, humidity and the type of storage play a decisive role.
- Storage location should be protected from light, cool and dry
- With a low humidity of 55 to 65 percent
- Optimal storage temperature of 10 to 18 degrees
- The basement usually best meets these requirements
- Put the nuts in air-permeable nets or bags made of natural fibers
- These can be standard onion or potato nets
- Then store it hanging from the ceiling
- Nets should be well ventilated all around at all times
- Airtight bags or sacks made of plastic are completely unsuitable
- Fruits would sweat and go moldy
- Avoid being near odorous foods
- Walnuts can be kept for several months
Alternatively, the nut kernels can also be preserved by freezing them. To do this, the dried nuts must be opened and the kernels packed in airtight freezer bags. Excess air is then forced out of the bag, the bag is closed and frozen accordingly. For better orientation, it is advisable to label the bags with the date of harvest or the date of freezing. Frozen walnuts can be kept for up to six months without any problems.
Tip: Freshly cracked walnuts can be kept for around four weeks, provided they are stored in an airtight container in a cool, dry place.