Hazelnut Processing 101

It is said necessity is the mother of all invention and at this stage in our industry growers need low-cost, but effective processing lines...so growers have been searching high and low for suitable equipment.....or building it themselves.  Below you will find photos and descriptions of processing equipment built, modified, or found by fellow growers.  Want to share what you've learned, built, or found?  Contact Jason Fischbach and he'll help you post the information on this page.
Disclaimer:  The information provided in this online symposium is only that...information.  Neither the UMHDI Research Team nor the University partners of the UMHDI make claims, assertions, or endorsements as to the effectiveness, safety, or functionality of the equipment shown below.  Buyer and user beware.  As with all equipment, there is always room for improvement.  Try stuff out, learn, and build a better mousetrap!  

Drying

Passive Solar
Most growers are drying their hazelnuts before husking, usually by stuffing the in-husk nuts into onion bags and hanging in a covered spot to dry. Depending on the weather this can take too long and possibly result in moldy nuts.  A faster option is to find an unused greenhouse in the fall.  Most bedding plant greenhouses are vacant in September and October and might make their space available. 
Low-Cost Passive Solar
If you don't have access to a greenhouse you could build your own passive solar boxes.  Putting a fan on each end can help remove humidity.  Such boxes are subject to nut loss from rodents.  Steepening the roof angle on the dryer box shown in the photo on the right or making the south-facing front transparent would help increase heating and drying.
Forced-Air Box Dryer
Using warmed and forced air will greatly speed drying.  This forced-air box dryer has an electric baseboard heater in a box at the bottom.  A fan circulates that air through the box with holes forcing the air up through the drying trays.  A humidistat controls a vent that exhausts the humidity out of the box, further accelerating drying.  

De-Huskers

DIY Bucket De-Husker
The bucket husker is a good entry point for small hazelnut growers.  It is easy to make and effective, but the husks to need to be dry for the husker to be effective.
Don Price Bucket Husker
File Size: 2092 kb
File Type: pdf
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DIY Barrel De-Husker
The next step up from the bucket husker, the barrel husker uses the same flail concept to knock the nuts out of the husk while pulverizing the husk at the same time.  It is a batch-type unit that requires loading the barrel and running it until the nuts drop out the bottom.  Like the bucket husker it works best with very dry husks.  A number of growers have built barrel huskers.  The file below shows photos of one such unit.
Mickelson Barrel Husker Photos
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X2000 De-Husker
Designed and built by John Bashaw of Pendragon Fabrication, the X2000 Husker is a continuous flow husker with built-in aspiration.  Like every prototype, improvements could be made but the drawings and parts lists are available.
X2000 Hazelnut Husker Plans
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File Type: pdf
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X12A De-Husker
Version 2 of the X2000 De-Husker.  The de-husking cylinder is similar to the X2000, but the bells and whistles have been removed to make it less expensive and there is better outflow.  The X12A removes the nuts from the husk, but the husk material must then be separated from the nuts with other sorting equipment.
X12 De-husker Brochure.pdf
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File Type: pdf
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Hasatsan H2200 Harvest and De-Husking System
Imported from Turkey, the Hasatsan H2200 is designed for Turkish production systems where nut clusters are vacuumed off the ground or from piles and de-husked.  The unit also separates the husk material from the in-shell nuts.  There are now at least five of these units in the US, including three in the Upper Midwest.  The video at right shows the unit working through green clusters.  Preliminary data show the unit is capable of removing 96% of the nuts from green clusters, greatly reducing the need for drying the clusters.
Hasatsan Brochure
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File Type: jpg
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Pendragon X12B De-Husker
The third version of the X2000, this new unit separates the in-shell nuts from the chaff after leaving the de-husking chamber. A recirculation feature results in better overall performance and less material handling. 

Low-Cost Aspirator (Separating the Husk from In-shell Nuts After De-Husking)

DIY Aspirator with Vibratory Feeder
Separating in-shell nuts from husks after de-husking is not complicated and doesn't require expensive equipment.  A shop-vac or larger dust collector, a cyclone, and some PVC is all it takes.  After de-husking, the mix of in-shell nuts and husk material is fed through this aspirator to clean the husk material from the in-shell nuts. Although this unit can be used to separate shell fragments from whole kernels, it is not a food grade unit and should only be used for cleaning in-shell nuts. 
UW-Extension Low Cost Aspirator and Vibe Feeder
File Size: 2682 kb
File Type: pdf
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Sizers

UW-Extension Roller-Sizer
This one-channel roller-sizer used by UW-Extension in Bayfield County is like many roller-sizers where the nuts roll down the channel between two spinning cylinders.  The distance between the cylinders increases down the length of the channel and the nuts fall through once the gap is wide enough. The slow-motion video shows "popcorning" due to the cylinders not being quite large enough in diameter.
Pendragon Single-Channel Roller-Sizer
This roller-sizer was built specifically for handling post-crack material and works well to sort kernels from un-cracked nuts.  It is built of stainless to meet food safety standards.  As with most single-channel sizers, it is not particularly fast, but because the channel gap and outflow chutes are so adjustable, the sizing can be customized to the material.
Badger Dual-Channel Roller-Sizer
This version of the roller-sizer concept features two channels to speed flow-through rates.  Channel widths and outflow chutes are adjustable providing essentially an infinite number of size classes.  In general, roller-sizers are slower compared to drum-sizers, but are effective and are very easy to customize sizing parameters.
Badger Drum-Sizer
The drum-sizer is a standard piece of equipment for nut processing.  This drum-sizer, designed and built by Dr. Dave Bohnhoff and his students uses slots instead of round holes for the sizing allowing it to size in-shell nuts and separate shell from kernel after cracking.  This prototype unit is currently located in Ashland, WI as part of the UMHDI Hazelnut Processing Accelerator.
DSR1260 Drum-Sizer
A collaborative project of UW-Madison, UW-Extension, and Pendragon Fabrication, the DSR1260 is built with the current scale and characteristics of Midwest-grown hazelnuts in mind.  The screens on the drum are easily swapped out based on sorting needs.  Use it to sort whole nuts or kernels by size.  Use it to separate shells from kernels.  The uses and customizations are endless.  Instead of buying different sizing units, now it's possible to just make screens to match the needs.

Crackers

Drill Cracker
This commercially available cracker is powered by a hand drill.  It is available at: drill-cracker.com.   It has a high throughput rate, but not all nuts are cracked the first time through.  It is a compression-based cracker and the gap between the spindle and anvil can be adjusted.  As such, the nuts must first be sorted into size classes.  The research bulletin below outlines one method to calibrate the cracker to achieve a high whole-kernel recovery rate.  The picture to the right shows the cracker mounted below a hopper and above a vibratory feeder that feeds an aspirator to remove the shell fragments from the kernels.
Drill Cracker Bulletin_Calibration
File Size: 287 kb
File Type: pdf
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DaveBilt Cracker
The DaveBilt Cracker is powered by a hand crank.  Those with some mechanical skills can hook up a drill or other power source.  Like the Drill Cracker it is a compression-based cracker and the two plates are separated by inserting washers.  Simple to use and effective.  Available at DaveBilt.com.
Universal Nut Cracker
The Universal is another version of a spindle compression cracker.  The space between the rotating spindle and anvil can be adjusted to calibrate to the size nuts being cracked.  The Universal is faster than the Drill Cracker, but performance is similar with respect to whole kernel recovery.   Spindle crackers work well with large nuts with thin shells.  Midwest-grown hazelnuts tend to have thick shells without much air-space between the kernel and shell, resulting in more split kernels, especially with smaller in-shell nuts.
Terminutter
The Terminutter is a novel hazelnut cracker that throws the in-shell nut against a metal plate in order to crack open the nut and release the kernel.  The velocity of the nut and angle of the metal impact plate are adjusted until finding the right combination that yields a high whole kernel crack-out percentage.  The unit was designed and built by Mark Shepard and Pendragon Fabrication.
Borrell Sample-Sheller
Manufactured in Spain, the Borrell Sample-Sheller is intended for the large-scale processors in Europe to crack out samples of hazelnuts when they arrive by the semi-load.  But, it is more than adequate to handle the current volumes of Midwest production.  The in-shell nuts are fed onto a vibratory sizing screen and then fall into the cracking mechanism calibrated to each size class.  The outflow is a mix of kernels, shells, and the occasional un-cracked nut.  The mix must then be separated with other equipment to separate the kernels from the shell fragments.  This unit is currently used in the Hazelnut Processing Incubator Facility in Ashland, WI and may be the only unit of its kind in the US right now.

Separators (Separating the Shell Fragments from Kernels After Cracking)

Badger Tilt-Bed Sorter
Tilt-bed sorters are very common in food processing and essentially are used to separate things that roll from things that don't.  This particular unit was built primarily as a research device to test different combinations of angles and feeding options.  A tilt-bed sorter can be used to separate stick-ons from in-shells (left) and to separate whole kernels from shell fragments and split kernels (right).
AHC Aspirator
Cracking and cleaning hazelnuts commercially requires a food processing plant license, though exact regulations vary from state to state.  Whether due to food processing rules or food safety concerns equipment that handles raw kernels should be food grade and easily cleanable.  This aspirator used by the American Hazelnut Company feeds the kernel/shell mix under an air column.  Whole kernels drop into a bin below and the shell fragments (and split kernels) are pulled into the waste box under the dust cyclone.
Southern Nut n Tree Re-Run Aspirator
This aspirator feeds material under a vacuum and can be calibrated to clean husk from in-shell nuts and shell fragments from kernels.  It is powered by a shop-vac vacuum and is available at sntequipment.com.  
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