A long wait is over. Seven years after we planted the first hazelnut bushes in our garden planted with trees, we were now the first real harvest. As it was previously at best a handful of nuts this year we have been able to rake in more than 2000 nuts.
Although I hazelnuts harvested in the wild many times I felt rather helpless as I stood there in the hazel grove and saw the countless clusters emerge. How do I know really when the nuts are ripe? And how am I going to have time to harvest them before all the animals who also likes nuts?
When I tried googling me to answer my questions, I received no satisfactory results. "The nuts are ripe when they fall down on the ground," it said on many pages. That may indeed be true, but from my observations of wild hazel stocks I know it is only a fraction of the mature nuts to even end up on the ground. Most of the mature nuts are the squirrels and birds when they are still on the bushes.
Even in the scientific literature, I went for a bite. There is some research on how fat ingredients of hazelnuts changes during ripening, but nobody seems to have bothered to answer my simple question about how I know if the nut is ripe. Here, then, is my own hypothesis about how it all works, which also leads to the answer to the question how we can have time to harvest the nuts before the squirrels.
After ripening nuts or how I have time before the squirrels?
The nut is connected via a membrane to the bush which provides the nut with nutrition during its growth. All nutrients must pass through this membrane located on the underside of the nut. Before the diaphragm starts to drop, it is basically impossible to pull off a nut without pulling off the whole bunch. At some point during the maturation process, nut, however, had all the nutrients it needs. Then I assume that the nut starts to produce some neurotransmitter which makes the membrane slowly impermeable and that the nut starts to come loose from its attachment. All processes required for the nuts ripen occurs within the nut from now. How long this process takes varies from variety to variety and is certainly highly dependent on external factors such as air temperature. After a while the nut is so loose that even a small squirrel can dislodge the. The best time to harvest the nuts for us humans is before then.
A big advantage we have against squirrels and other wild nut lovers is that we can let the nuts after mature indoors where it's warm and dry. Because I am convinced that the maturation process after a while only continue in the nut, we can harvest the nuts earlier than the wild animals. To test how long the maturation process has come, I take hold of a bunch of nuts and then use your thumb to press any nut sideways. If it releases without much effort is cluster ready for harvest. It will plop when the nut jumps out of its holder. If it does not release the hold bush still pumping nutrients into the groove. Or the nut empty or damaged. Since it is the nut itself as a signal that it is ripe, damaged or empty nuts not initiate lossningssprocessen. Empty and cracked nuts release therefore never from their strongholds, something that is good to know when it's time to take care of the harvest. On the other hand releases filled, healthy nuts Always mount, provided they are mature enough.
With this knowledge, I went then over my shrubs periodically and checked maturity. Not surprisingly, it was on the south side of the bushes, nuts ripen first. There could be a difference of three to four weeks in maturity between sun- and the shadow side of the same bush.
What if I harvest too early?
At the beginning of the harvest, I made the mistake to harvest the entire shrub as soon as the first nuts were finished on one side. I did not want to get rid of all of the great harvest only because I waited a few days too long. To harvest too early means that the important processes that take place inside the nut is not completed. It is entirely possible, and also really good to eat green, immature hazelnuts, but you can not get those nuts that after mature properly then. What happens is that the nuclei shrink very much, something that probably has to do with the change of the fatty acids in nuts. In immature nuts are fatty substances are not stable and the water level is still very high, which simply means that there will not be much left to eat after a few weeks. Therefore I turned rather quickly to reap the rounds.
When the nuts are harvested well requires some processing both to favor the ripening process and to make them shelf stable as possible. For the most part, I harvested the whole bunches. The best thing is to simply spread out all bunches in an airy, ventilated, dry and not too cold place that is also mussäker. Where can they be until the nuts are fully mature and then just shake them out of their shells. Both the housings and the nuts turn brown after a while, which is a good sign that they are mature. Nuts from loosening is to say either damaged or completely empty and it is not worth the time to roll them out brackets.
If you are short of space, you can also pick out the nuts from their mountings immediately after harvest. One mistake I made was that I hung the whole bags of nuts in the roof. The nuts in the middle then got enough air and began to rot on the surface, something that can lead to the production of different very unhealthy fungicides (mykotoxiner) the nuts. Therefore it is important that each nut is airy until the water level is so low that it can not rot anymore. This process can take a number of weeks. In ancient times it sounded nuts even be on the wind until Christmas Eve so that they would be really dry .
Our crop variety for variety
In total, we have about 20 cultivars of hazelnuts and between hazel (Corylus x colurnoides). In addition, we have planted dozens vildhasslar from different areas in Sweden to ensure that we get good pollination of our great fruity name resorts. This year was the first year a wild hazel which we picked from a nearby stand blossomed. Of the big name resorts fruity it was six varieties that gave real harvest. The table below shows a summary of yield per bush. All shrubs are planted 2013, except the variety 'Cosford' planted 2012.
The shrub whose nuts ripen very first was wild hazel, more than two weeks before the first cultivar matured and over a month before most other shrubs began to get ready harvest nuts. The nuts, however, was very small in comparison. 'Frühe Lange Zellernuss' frequently recommended in the literature, and it was very quite early (med avlånga nötter). ’Kentish Cob’ (=’Lambert’s Filbert’) matured shortly thereafter, but Bush is still quite small, and the harvest was then. 'Halle'sche giant Sap (= ‘Jättenöt från Halle’) the kind that clearly has taken the best of cultures. I purchased the shrubs as 'Wunder aus Bollweiler', but according to a research article from 2006  är ’Wunder aus Bollweiler’ genetiskt identiskt med ’Halle’sche Riesennuss’, so I use that name to come. Two of these shrubs gave more than 2 kg Combine, which is a really good value when compared with the figures in the literature. The two real 'Cosford'-bushes gave for their size and age, a surprisingly poor harvest, although the quality of the nuts were very good. A pleasant surprise was the variety 'Butler' that is produced in the United States gave the harvest for the first time. 'Butler' was the kind that gave the largest single nut, although the average was slightly lower.
|Sort||Skördedatum||Vikt med skal, fresh (g)||Antal fyllda||Vikt per nöt (g)||Antal tomma||Andel tomma (%)||Note|
|Vildhassel||20 August||460||248||1.85||0||0||Från ett lokalt hasselbestånd|
|Cosford 1||8 september||120||60||2||6||10||Förmodligen felmärkt, ser mer ut som vildhassel till storlek.|
|Frühe Lange Zellernuss||8 september||1035||365||2.84||29||8||Två buskar|
|Kentish Cob||13 september||139||67||2.07||0||0|
|Halle'sche Riesennuss 1||18 september||2737||827||3.31||47||6||Skördade för tidigt|
|Cosford 2||18 september||850||196||4.34||7||4|
|Cosford 3||30 september||200||41||4.88||0||0|
|Halle'sche Riesennuss 2||30 september||1126||298||3.78||10||3||En del nötter fortfarande inte mogna|
|Halle'sche Riesennuss 3||30 september||2217||503||4.41||20||4||En del nötter fortfarande inte mogna|
|Halle'sche Riesennuss 4||30 september||170||55||3.09||5||9||Liten buske|
|Halle'sche Riesennuss 5||30 september||182||43||4.23||3||7||Liten buske, fåglar tog en del av skörden|
|Webb's Prize Cob||0||0||0||0||Fåglar tog hela skörden!|
The column "Number of empty" requires some explanation. When I started to reap from the bushes were already a lot of bunches of nuts on the ground. Upon further investigation, I discovered that all the nuts lying on the ground was empty. It seems that the hazel bushes repel whole bunches when they somehow realize that they only contain empty nuts. Probably it is a neurotransmitter that is not sent from the nut to the bush that allows the start of the rejection process. Very handy for me when eliminating time spent on managing empty nuts. The empty nuts remaining in the table, then, such as shared cluster filled with nuts. Overall, I think the percentage of empty nuts are low, especially in comparison with literature values generally above our values . One reason why the harvest was relatively high, it may also be that of hazelnut growers feared pest nötviveln not present with us. More on the bad guys and how we conduct ourselves in relation to it will in the next post.
 Boccacci, P., A. akka, and R. Botta, DNA typing and genetic relations among European hazelnut (Corylus avellana L.) cultivars using microsatellite markers. Genome, 49(6): p. 598-611, 2006.
 Pettersson, B., I. Svanberg, and H. Tuñón, Nuts: ethnic biological reader. Studentlitteratur, 1999.
 Solar, A. and F. Printing, Characterisation of selected hazelnut cultivars: phenology, growing and yielding capacity, market quality and nutraceutical value. Journal of the Science of Food and Agriculture, 91(7): p. 1205-1212, 2011.