Farmer Built Spelt Dehuller

Project Overview

Project Type: Farmer
Funds awarded in 2011: $7,369.00
Projected End Date: 12/31/2014
Region: Northeast
State: New York
Project Leader:
Nigel Tudor
Weatherbury Farm

Annual Reports

Information Products


  • Agronomic: spelt


  • Education and Training: demonstration, display, on-farm/ranch research, workshop
  • Farm Business Management: marketing management, value added
  • Production Systems: organic agriculture

    Proposal summary:

    While spelt works well in an organic system, the hull presents a tenacious problem. With the hull on, the bulkiness of the grain doesn’t make it cost effective to ship spelt long distances. Larger processors want to buy entire truckloads of unhulled spelt and a small farmer would probably not have the volume of spelt to fill a truckload. The hull on spelt also prevents the small farmer from producing their own flour and selling their flour and whole grains locally. Spelt is gaining in popularity and products made from it can be found in most grocery stores. People with wheat allergies often can tolerate spelt and other people feel that they can digest spelt easier than wheat. Unfortunately the small farmer is shut out from this niche market by his inability to remove the hulls. In 300 miles from my farm, I have been able to find only 4 people who dehull spelt. The closest person with a dehuller is over 100 miles away. When you consider the cost of shipping in addition to the cost of custom dehulling, it makes this option prohibitively expense for me and many other small farmers like me. Additionally, people that do custom dehulling often don’t do identity preserved lots for less than truckload quantities. This is very important to the customers buying directly from small farmers as they want to buy a product that the farmer grew and not a mixture of product from several additional unknown farms. If the small farmer has a dehuller, its use wouldn’t be limited just to spelt. In addition to spelt, the ancient grains of Emmer (also known as Faro) and Einkorn could be dehulled with the dehuller I am proposing; thus offering an additional niche product for the small farmer. Also, if the farmer is growing hull-less oats he can use the dehuller without the rotary screen to remove the hulls from the oats that have still retained their hull after combining. Value added products is one strategy for the small farmer to remain viable. Spelt is well suited to this strategy and very popular in organic production. Currently there is no small scale equipment that would allow the small farmer to dehull the grain so that it can be used as a locally produced staple food or ground into flour. There are commercially available dehullers but their cost is such that over 100 acres of spelt would need to be grown to justify their purchase. The goal of my project is to build a spelt dehuller that could be built and used by any small farmer. The spelt dehuller will use a rotary screen with a grating – peeling- sizing action common to the German style dehullers but scaled down for the smaller farmer. The unit will also feature a simple aspirator to remove the free hulls. The spelt dehuller will be featured at a field day and on a page of our farm’s website. The plans, photos and project notes will be compiled into a book that will be put into a PDF format so that it can be widely disseminated.

    Project objectives from proposal:

    I have studied the commercially available dehullers and have come up with a dehuller which is a scaled down version of the German style dehullers with an integral aspirator. I have priced out all of the commercially available components. I have used my 16 years of metalworking and machining experience to create a ballpark budget for the steel and amount of time needed to complete the project.

    The machine will have a hopper at the top where unhulled spelt is fed into the machine. The hopper will have a magnetic grate which will prevent potentially damaging pieces of steel from entering the dehuller. At the bottom of the hopper there will be a 4” diameter sliding gate that will regulate the feed rate of spelt into the hulling chamber.

    The main part of the dehuller will be powered by a 7 ½ Hp motor that has its speed controlled with a variable frequency drive. In my project notes, I will describe how this motor could be replaced by a tractor driven PTO shaft, so farmers who don’t have 3 phase electric or an adequate electric service could still benefit from this dehuller technology.

    The motor will spin 2 free swinging hammers with paddles inside of a round wire space cloth cage (space cloth is wire screen with precisely sized openings). The hammers will spin the unhulled spelt around the inside of the wire cage. The abrading action of the cage will peel off the hull layer by layer. Once the spelt grain is dehulled, it will fall through the openings in the wire cage.

    Once the grain has been dehulled, it will pass through a short column of air in the aspirator where the loose hulls will be sucked away. This aspirator is necessary because if the hulls are not removed, they will overload the next machine (which will be either a seed cleaner or gravity table which will separate the hulled from unhulled grain). The aspirator fan will be powered by a 1Hp motor whose speed is controlled with a variable frequency drive. The variable frequency drive will allow the air speed in the air column of the aspirator to be fine tuned.

    The whole unit will sit on a stand so a bin or auger to the next machine can be placed underneath of it.

    Due to the nature of the machine, some parts will need to be machined but a large part of the dehuller will be able to be built by the farmer on the farm.

    After finalizing the details of my design I will draft blueprints in CAD. As I am building the dehuller I will take pictures and make notes to help anyone who wishes to build their own dehuller. When the dehuller is complete I will test it. If any design changes need to be made, I will make them and then test the dehuller again until it works to my satisfaction. Finally I will compile the blueprints, pictures, and notes into a book.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.