UVM Extension Ag Engineering

This blog post is for those using or considering a converted washing machine as greens spinner. 

Background

For background information on several different types of greens spinners and general thoughts on using washing machine conversions see this blog post

Shopping Tips

What to look for when shopping for a washing machine for a greens spinner? The details are in the drum. Minimize seams, nooks and crannies for an easy to clean surface.

There are a few things to consider when shopping for a washing machine to convert into a greens spinner. Like most things, it comes down to:

  1. How much you want to spend, and
  2. What features are important to you.

Option 1 – A Basic Machine

There are few things you need to look for in searching or a washing machine that will be used as a greens spinner. A good rule of thumb is: The simpler the better. Fancy electronic controls are not used for this application; you only use the spin cycle.  The pictures below show a Whirlpool WTW500DW model which was used for our first review. Most models on the market are put together in similar ways, but individual washers will vary. This washer and others like it can easily be purchased at box stores. You can expect to pay $500-600 for these basic models. Other models are available from different manufacturers but they have not been evaluated by us yet.

Key Points

A brand new Whirlpool before the chopping block. (WTW500DW)

Top-loading washers are needed for greens spinning. Front-loading washers pose challenges in both use and cleaning.

Washers with an “impeller” or wash plate rather than an “agitator” up the middle allow easy use with basket inserts and require less modification.

This machine, an Amana NTW4516FFW, has an “agitator” instead of an “impeller” or “wash plate”. The agitator shaft sticks up high in the drum – A no-go for using a basket insert!

Some washing machines have an agitator that can be removed, providing enough clearance above the drive shaft for using a basket insert. But, some driveshafts stick-up too far which prohibits the use of a basket!

Start with a new clean washer. It is tempting to use the free, used washing machine you found on the roadside. But, remember, you are washing salad that people put in their mouth, so these machines need to be kept extremely clean. Because of this, we also recommend using a basket insert to spin your greens over directly placing them in the drum, or using a laundry bag. This makes the basket (which is easier to keep clean) the primary food contact surface and not the components of the spinner.

Whether you’re starting with a new washer or performing maintenance on your existing one, this next tip will ensure you are minimizing harborage points for bacteria and foodborne pathogens.

Downsides of “Basic” machines

A common spinner conversion, with many hard to see, hard to reach, and hard to clean areas.

Hard to Clean – Areas between the sidewalls and the drum are hard to access for cleaning.

Visually Unappealing – Washing machines are not visually appealing, especially when they’ve been hacked for farm use. Technically speaking they can be cleaned and maintained (read more tips below) to reduce produce safety risks. However, they can raise a flag for an auditor or inspector.

Drum Modification Required – Baskets don’t fit securely in the drum, and additional “bumpers” need to be installed for use.

Can Be Noisy – Loads can get out of balance, especially when modifying the drum to fit baskets. This causes the machine to wobble and shake. Sometimes the drum will even slap the sides of the machine. This makes for a very loud workspace and excess wear on your machine.

Sharp Edges – A hacked top or the edges of side panels can be sharp. The temptation to cover these with a split hose reduces the risk of cuts but increases harborage risk and creates additional pathogen growth locations.

Washer/Spinners have been used both with white Rubbermaid tubs and orange baskets.

Option 2 – A Commercial Machine

The second option we have explored is a commercial washing machine. These machines are made for the commercial market and are generally benefit from a more robust design. They really are the “cat’s meow” when it comes to washer conversions. They come with a price premium, but it is likely well worth it considering the benefits. The model we reviewed is the Speed Queen TC5. These are not found in the typical box stores but, rather, in appliance stores. These machines are in the $900-1,000 price range. Other commercial washer models from various manufacturers like Whirlpool etc. are available, but their build and features have not been evaluated by us yet.

Beneficial Features

There are several benefits that the higher end washer gains you that we think is worth the extra cost. Everything from the ease of modification, quality of the machine components, hygienic design of the final build and daily ease of use.

The company provided an exploded view right in their marketing material! (photo from speedqueen.com)

Ease of Modification – These washers are designed and built with clear attention to detail. Parts are designed to be easily removed or replaced and not designed cheaply as a use-and-replace appliance.

This model does have an agitator, but it can be easily removed close to the bottom of the drum to allow the use of a basket insert! (Speed Queen TC5)

Low Attachment Point Agitator – This brand of washer DOES have an agitator up the center, however the way it connects to the drive shaft is low enough in the drum so it doesn’t interfere with using a basket insert.

Direct Fit Baskets – The drum is the right diameter to fit orange harvest baskets without bumpers or spacers to secure the load.

We found this bottom mount design has many nice benefits when used as a greens spinner. (photo from speedqueen.com)

Quieter Operation – This machine has a bottom-mounted design (supported from a base on the floor) rather than chassis mounted (hung from the side panels). This keeps the load in better balance reducing excess vibration, noise and stress on the components. It also allows the top to be more open and reduces sharp edges and harborage points.

Improved Electronics – The motor used in a Speed Queen is a 3/4hp vs. a 1/2hp on a basic washer, more power and longer lifespan. The wiring harness uses a higher gauge wire and is easy to dissemble wire to a timer switch.

Single Piece Drum – The drum on the speed queen’s is fully stainless steel and has smooth drains holes and does not include stamped, molded or sandwiched pieces of plastic. These extra pieces and design features on the Basic Model create seams and sharp edges that are hard to clean and sharp to handle.

Almost as easy to disassemble as the picture shows. It was designed well and built to last. (photo from speedqueen.com)

Automatic Drum Brake – This machine is equipped with a mechanical brake that automatically stops the drum from spinning at the end of the cycle. This reduces the time it takes for the basket to slow down and stop. Basic machines coast to a stop and users find themselves waiting, or using their hands to stop the drum early.

Compact Design – Since the unit is bottom-mounted, the sides of the machine are not needed, and can be removed. This makes the unit lighter and take up less space in your wash-pack area. This makes it a more enjoyable place to work providing more open space and less visual clutter. (+1 for not looking like a misplaced washing machine, or Frankenstein appliance anymore!)

Easier to Clean – Removing the sides also increases the ability for the machine to fully dry between uses. This reduces conditions that favor growth of bacteria and other pathogens.

Our Speed Queen prototype. Working well, but could use a skirt to protect the motor from nearby water splashing.
Fits orange baskets without modification, and automatically brakes at the end of the cycle!

Early findings on the Commercial Washer Model

No side panels make it a smaller unit in the packshed, and easier to work around.

We have our first version dropped off at a partner farm (Footprint farm) for a long term use test. Early reports suggest that it’s a great washing machine spinner. Concerns of water getting on the motor prompted the need to add a skirt over the electronics to deflect splashing of nearby water. We also increased the size of the drain holes in the bottom of the drum to make the daily cleaning (hosing out small leaf material) quicker and easier. Taylor and the crew repeatedly comment about how nice and quiet the machine operates. Yay for hearing the radio, and other crew members as you pack for customers!

NOTE: The Speed Queen model TC5 and TR5 differ slightly: The TR5 does not have the brake feature.


Not sure if a washer spinner is right for you? Learn about other options

Looking for best practices and how-to info on cleaning and maintenance? Check out these videos.

*Stay tuned for a more detailed conversion SOP for both models mentioned in this blog post!

Washing Machine Greens Spinners: Shopping Advice

This blog post is for those using or considering a converted washing machine as greens spinner. 

Background

For background information on several different types of greens spinners and general thoughts on using washing machine conversions see this blog post

Shopping Tips

What to look for when shopping for a washing machine for a greens spinner? The details are in the drum. Minimize seams, nooks and crannies for an easy to clean surface.

There are a few things to consider when shopping for a washing machine to convert into a greens spinner. Like most things, it comes down to:

  1. How much you want to spend, and
  2. What features are important to you. Continue reading “Washing Machine Greens Spinners: Shopping Advice”

Ag Engineering Downloadable PDF Resources

All of our resources are available here on this blog. However, if you are looking for a printed handout, here is a list. These are all of the PDF documents that we share during workshops, meetings, and presentations. All links will open the PDF in a new tab.

Handouts

Common Vegetable Wash/Pack Equipment List

Backflow Prevention for Produce Farms

Farm Cooler Checklist

Floors for Vegetable Wash, Pack & Storage Areas

Forced Air Cooling on The Farm

Forced Air Cooling Field Trial Results

Greens Spinners for Farm Use

Hygienic Design for Produce Farms

Last Resort Farm not Stalled by Dairy Barn Conversion for Produce – Case Study

Laser Scarecrow

Mighty Clean & Comfortable – Mighty Food Farm Case Study

On-Farm Hygienic Design Review Checklist

Rats & Rodents

Sanitizer Dosing Systems

Smooth and Cleanable Surfaces

The BarnHouse Optimized for Modern Day Vegetable Farming at Footprint Farm – Case Study

Vegetable Wash Sinks, Tanks, Tubs and Basins

Slide Presentations

2019 August 1 Postharvest Workshop at Pleasant Valley Farm

2019 May 20 Building a One-way Street: Backflow Prevention Strategies for Produce Farms

2019 February 16 Postharvest Workshop at NOFA Vermont Winter Conference

2019 January 22 Postharvest Wash Pack and Storage in Fairlee VT

2017 December 17 Postharvest Cooling and Curing, at NEVFC in Manchester NH

2017 December 14 Postharvest Handling Can Improve Fresh Market Success at NEVFC in Manchester NH

 

Washing Machine Greens Spinner Workshop

Build a greens spinner out of a washing machine! (Speed queen model shown here)

Have a washing machine that you want to convert into a greens spinner?

Have you already done the conversion, but want to improve it?

Join us for one of two hands-on, intensive workshops this fall focused on getting the job done and doing it well. Continue reading “Washing Machine Greens Spinner Workshop”

Greens Washline from China

With innovative tools becoming more available for salad greens production from field prep through harvest, mixed greens are becoming more attractive for farmers. Postharvest handling and wash/pack still causes a bottleneck for many farms. Today we share some knowledge on a piece of equipment recently adopted at Jericho Settlers Farm in Jericho, VT.

This Greens Washline is made by China Joy Equipment. They call it an “Air Bubble Washing Machine.” This has been an affordable piece of equipment to allow their farm to scale up greens production for $13,900. Mark Fasching from Jericho Settlers Farm was gracious enough to share some of his experiences sourcing this machine from the other side of the world.

Continue reading “Greens Washline from China”

Ventilation in Greenhouses and High Tunnels

I had the pleasure of facilitating a workshop at the 2019 NOFA-MA Summer Conference about Ventilation in Greenhouses and High Tunnels. It provided an opportunity to collect information from various sources, ground truth observations with growers, and to revisit some fundamentals. The big takeaway, for me, is that there are many, many ways to ventilate a protected culture environment and opportunities for improvement abound.  I hope this review provides a framework for troubleshooting some issues that may be common in the field.

Continue reading “Ventilation in Greenhouses and High Tunnels”

Wheels Keep Things Rolling at Root 5 Farm

A PDF of this case study is available for download here

Danielle Allen and Ben Dana own and operate Root 5 Farm in Fairlee, Vermont. This organic vegetable farm on the Connecticut River provides over 200 CSA members, farmers market, restaurant, and wholesale customers with local, healthy food. Over 100 different varieties of crops are grown on the 38 acres that make up the farm. Continue reading “Wheels Keep Things Rolling at Root 5 Farm”

Forced Air Cooling: Field Trial Results

Last summer we performed a series of precooling trials using small-scale forced air coolers to cool eggplant, watermelon, strawberries, blueberries, zucchini, and roasting peppers. The forced air cooling was done in parallel with standard room cooling and was shown to result in cooling rates ranging from 1.2 to 2.2 times faster than room cooling. This test demonstrated the feasibility and benefit of simple forced air cooling systems to smaller scale farms.

Continue reading “Forced Air Cooling: Field Trial Results”

Hygienic and Sanitary Design for Produce Farms

Hygienic design intentionally creates or improves spaces and equipment so they can be cleaned and sanitized as appropriate.

This joint illustrates how intermittent welds lead to a gap, or sandwich joint that can lead to harborage. A continuous weld that is then ground smooth would lead to a seal and be easier to clean, sanitize, and dry completely.

This post, associated PDF guide and checklist (PDF and Excel) are tools we developed to help apply hygienic and sanitary design practice on produce farms. These tools cover the five key principles of hygienic design for produce farms:

  1. Visible and Reachable Surfaces
  2. Smooth and Cleanable Surfaces
  3. No Collection Points
  4. Compatible Materials
  5. Preventing Contamination

Continue reading “Hygienic and Sanitary Design for Produce Farms”

Backflow Prevention for Produce Farms

Check valves are one of several ways to prevent backflow.

The intentional, directional, and reliable flow of water is important to ensure agricultural water is “safe and of adequate sanitary quality”.

This post provides information on the importance of backflow prevention and some common practices that help mitigate the risk of backflow. You can also view presentation slides and a recorded webinar on this topic that were provided for the May 2019 Produce Safety Alliance Educators Call.

PDF Download of this information: Backflow Prevention Factsheet

Continue reading “Backflow Prevention for Produce Farms”

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