Mobile Hop Dryer

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2017: $7,500.00
Projected End Date: 12/31/2019
Grant Recipient: Ohio Valley Hops, LLC
Region: North Central
State: Ohio
Project Coordinator:
David Volkman
Ohio Valley Hops LLC

Information Products


  • Agronomic: hops


  • Crop Production: food product quality/safety, postharvest treatment
  • Production Systems: general crop production

    Proposal summary:


    Our problem is find a way to quickly dry hops to the ideal moisture content for processing, while reducing individual farmer investment by creating a shareable resource.
    Drying hops is time sensitive from start to finish. The sooner that harvested hops can begin and finish the process, the higher the quality, and more marketable. Hops (like any vegetative product) begin to break down as soon as they are picked, potentially resulting in off flavors that reduce their marketability. Conversely, immediate entry into the drying process and rapid completion prevents damage, and maximizes oil and acid retention that give hops the flavors and aromas desired, improved pelletability and storage, and thus sales potential and price point. Many growers rely on other farmer’s drying facilities, increasing travel and time between harvest and drying. Farmers who have immediate access can produce a much higher quality hop than those who don’t. Several growers in Ohio also process hops into pellets, the form required by brewers. These processors report most hops they receive are not dry enough, requiring them to be redried, further degrading their quality.

    We know of one commercially available small-scale dryer; a fan unit with blueprints for the dryer that costs $3800, materials not included. Several growers have built fixed drying facilities which allow on-farm drying which have proven to be effective and efficient. However, they cost several thousand dollars and permanently take up floorspace. Practically and financially, not every farm needs to tie up space and money in a dryer. Sharing is viable, since drying takes ~48 hours, and Ohio’s harvest starts in the southwest in July and continues through September in the northeast with about a seven to ten day harvest window per variety. It is practical that numerous growers could use one mobile dryer.


    We propose to build a prototype mobile hop dryer that incorporates best drying practices from small-scale hop growers. It would facilitate immediate drying after picking. It will be shared among a group of growers who manage their harvest dates to maximize utilization, eliminate the cost and inefficiency of a fixed facility, while improving the quality and marketability of their crop. The design could be replicated and shared collaboratively by other groups of growers.

    It will be built in an enclosed trailer, with a two-step, 48 hour drying process involving high volume air movement for initial drying and then lower volume conditioned air for finishing, powered by a generator for complete mobility, with food safe materials and practices as required. Although using proven drying techniques, we will test to ensure this design is able to accomplish its’ intended goal of drying the crop to accepted moisture content standards within approximately 48 hours.

    We will cooperatively share the dryer with 3-5 Ohio based farmers the first year to test scheduling and sharing, and attempt to schedule more the second year to determine the optimal number of farms that can be served by a mobile hop dryer.

    Project objectives from proposal:

    1. Build a mobile hop dryer that will quickly dry hops to national quality standards for processing, storage and sale.
    2. Improve crop quality by decreasing time between harvesting and drying of hops, and testing the mobile hop dryer prototype for quality of product.
    3. Increase farmers' profitability by allowing sharing of the mobile hop dryer among collaborating growers, reducing the need for all growers to build fixed facilities, saving them money, and improving crop quality and marketability.
    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.