Food Drying and Preservation in a Greenhouse Solar Dehydrator

View the project final report

• 2014 annual report

Commodities

• Fruits: melons
• Vegetables: beans, beets, broccoli, cabbages, carrots, cauliflower, eggplant, garlic, greens (leafy), leeks, onions, parsnips, peas (culinary), peppers, cucurbits, radishes (culinary), sweet corn, tomatoes, turnips
• Additional Plants: herbs

Practices

• Crop Production: food product quality/safety
• Education and Training: extension, farmer to farmer, on-farm/ranch research
• Energy: energy conservation/efficiency, energy use, solar energy
• Farm Business Management: value added
• Sustainable Communities: local and regional food systems

This project sets out to build a solar dehydrator that will utilize empty greenhouse space during the summer season to create value-added dried products out of surplus/ blemished produce. Pond Hill Farm is in the unique position to grow, harvest, and process our own fruits and vegetables from field to fork, serving our produce in our daily Garden Cafe and canning our goods onsite in one of our two licensed commercial kitchens. We are hoping to utilize our existing resources to diversify our value-added products by dehydrating produce during the season's peak in our empty and otherwise unusable greenhouse space. Our previous success with greenhouse-dehydrated kale chips, sun-dried tomatoes, and fruit leathers has inspired us to create a replicable model for other farmers to imitate for their own season-extension successes, and minimize the waste of an otherwise perishable crop. We hope to address the food-safety concerns by consulting our local MDA inspector, researching appropriate drying techniques, monitoring humidity and temperature levels throughout the day, and testing our products for water activity level. There are three universal farm issues that our project sets out to address: 1) Having local food products year-round in a northern region with a relatively short growing season 2) Finding a profitable use for surplus and/or blemished produce to minimize food/ crop waste 3) Inefficient utilization of greenhouse space during summer months.

Over the course of the year, we plan to measure a variety of components in order to assess this project as a model of sustainability and productivity.

We intend to keep detailed records of temperatures reached and time necessary to dry individual goods, as well as testing our products to assure food safety and measure water activity level, in order to determine what precise environmental factors must exist in order to successfully and safely dehydrate foods and create a shelf-stable product.

To measure the economic benefits of our project, we will track the number of personnel hours needed to maintain operation of the dehydrator, including dehydrator construction hours, time cleaning and processing the produce, as well as packaging and marketing the items. We will track the amount of product and sales dollars to measure against all other expenses along the way to determine certain product’s profit margins, and whether or not our design has the ability to pay itself off in the long or short-term.

We will measure social benefits by tracking participation levels in the workshops and outreach events we participate in, and include evaluations where possible. We will gauge interest levels to our project and products by tracking visits to our website’s dehydrator page.