Modeling Efficiency and Safety in a Vegetable Wash and Pack House

Problem

On our farm we use too much energy, water, and labor to wash and store our produce in a way that supports current best practices for food safety. We are pretty efficient in our use of water, energy and labor in the production of our crops as some of these things are scale neutral, and we have focused a lot of our mental energy on finding the best, most efficient and ergonomic way to do things in the field, however, when we bring things to the pack shed, our efficiency plummets. This is partially due to the lack of cost-effective and efficient equipment for produce washing on our scale. For example, we grow lots of carrots, beets, radishes, salad turnips, and parsnips, all crops which sell much better, and for higher prices, with tops on. Unfortunately the lowest priced commercial bundled root washer is over $3,700, while the next step up is tens of thousands of dollars. Because of this, most growers at our scale just use hoses and hand-held sprayers, often taking hours of wet, uncomfortable labor and hundreds of gallons of water to wash one market's worth of carrots. On our farm, we currently take about three hours, and about 400 gallons of water, to wash 150 bundles of carrots. We think there have to be better solutions for small-scale growers, which will reduce our energy, water, and labor use, leaving us with cleaner produce, better profits, happier help, and a better quality of life.

Solution

To this end, we have several changes we would like to make in our pack shed; 1. Build a better bunched veggie washer. Dave Hambleton of Sister Hill Farm in New York has a proto-type which we would like to build a version of, using a pressure washer, three spray nozzles, a five gallon bucket, and an adjustable stand. He states that using this his crew can wash up to 150 bunches of carrots in less than an hour, and because of the increased pressure, his water use per minute is less than a third of what we are currently using. By perfecting his model, which he admits has several shortcomings, we could use 90% less water, and 30% less time. 2. Add energy conservation measures to our walk-in cooler, which is one of the biggest energy users on our farm, including insulating the floor, adding slit curtains to the door, and installing a high efficiency split-unit ac unit to work with our Coolbot, which currently uses a much less efficient window unit. 3. Purchase and utilize a hand pallet truck, using miniature plastic pallets to move stacks of produce totes in and out of our cooler, rather than moving them by hand, as we do now. This will reduce our time and effort shuttling produce into and out of the cooler, meaning healthier backs and shoulders, while also reducing the number of times per hour that we open the cooler door, thereby saving energy. 4. Finally, we would like to install a small solar array on the roof of our packshed, to power the well pump, pressure washer, and a.c. units. With the recent dramatic reduction in the cost of solar panels, for a pretty minimal cost we can create a model for sustainable farm pack sheds.