The terms "sprout" and "microgreen" are designations for two different stages in the normal growth of plants. A sprout is formed at the very early stage of germination and is complete in 4-6 days. A microgreen, on the other hand, takes 8-14 days to develop, and is complete when the first two leaves of the plant have formed (the cotyledon stage).
Sprouts are eaten whole, including the root, the seed and the stem. Microgreens, on the other hand, are cut about 1/2" above the root, and the roots are not consumed.
Sprouts are grown with a great deal of water, not using soil or a soil substitute. This abundance of water makes a handy growing medium for bacteria, should any bacteria enter the system.
Regrettably, an outbreak of E. coli affected over 6,000 people in Japan in 1996, and this outbreak was linked to contaminated radish sprouts. Sprouts from an organic farm in Germany were determined to be the source of an E. coli breakout in 2011 which infected nearly 4,000 people, and caused 53 deaths. These outbreaks heightened public health concerns about the safety of spouts, and the safety of farm food in general, particularly food that is eaten uncooked, such as produce.
Contaminated seeds have been recognized as the main source of bacterial pathogens in most sprout-related outbreaks, as reported by the National Advisory Committee on Mictobiological Criteria for Foods (1999). This is why Viva-the-Greens purchases seeds only from a trusted source, True Leaf Market, and we test every seed for pathogens.
The U.S. Food Safety Management Act of 2011, was the most sweeping reform of U.S. food safety laws in 70 years. Included in the FSMA is the Produce Safety Rule which outlines safety standards for growing, harvesting, and holding of produce for human consumption.
The Viva-the-Greens! Farm Food Safety Plan was prepared by Christian Overman (co-owner/manager) for any buyers who may have questions about how we farm, and/or for any possible audits by federal, state or county agencies. Our Farm Food Safety Plan is available to anyone upon written request.
Christian completed his food safety training class in January, 2019, which was facilitated by Washington State University in cooperation with the Washington State Department of Agriculture. The curriculum used for this training was USDA-approved, and was developed by the Produce Safety Alliance.
Mold looks like a "spider web" around a seed, or on top of leaves. Mold is not to be confused with root hairs, nor is it to be mistaken for the thin white strands of a corn starch grow-pad.
Root hairs develop when water supply is lean. Roots, by design, grow "hairs" to try to find as much water as possible when it is not in abundance. The challenge of microgreen farming is to provide sufficient water for microgreens to grow well, but to not over water the plants, which may lead to mold.
We keep the humidity in the farm down to 50 percent or lower.
The other challenge is temperature. We keep our farm within the temperature range of 68-72 degrees Fahrenheit. There is no need for warmth to grow healthy microgreens.
Do not spray your microgreens from the top. Doing so may cause water droplets to lodge between the crowded stems and lead to rot or mold. Water your microgreens from below. Set the clamshell container in a pan of 1/4" water for 4 seconds every other day to allow the paper towel and grow-pad to soak up water through holes in the bottom of the clamshell. Doing this will keep your microgreens alive and fresh for 5+ days.
Always refrigerate your microgreens until used.
Sunflower seeds are particularly prone to mold. Here you see the growth of mold from a sunflower seed. The root spikes in the photo are normal.
Mold can be brought into microgreen farms on sunflower seeds, which are hard to sanitize without bleach, which we do not use on our seeds.
Do not confuse root hairs with mold. Root hairs are typically found below the stems, enveloping the roots. They may resemble mold when the hairs are tiny and prolific, as in this example of broccoli microgreens about 11 days old. The fine, white root hairs envelope the roots much like white clouds. Harvest your microgreens about 1/4"-1/2" above the grow-pad.
Equipping the farm so the temperature is right for growing microgreens and wrong for growing mold took some doing. It requires two dehumidifiers and an air conditioner. We also run a PlasmaWave air purifier 24/7.
Here is our grandson, Gabriel, who just drilled a 6" diameter hole through the solid concrete wall of our daylight-kitchen-turned-farm, to accommodate the necessary outflow for the air conditioner. Took him 6 hours!