Over the course of our sprouting experience, and with the rise in popularity of our true flood-and-drain style approach (installed in various scales over 115+ farms across the US!), we have learned quite a bit not only about how to improve our process, but also how to hone the messaging so that this topic remains approachable by others in an easy to understand manner. Our goal as a Permaculture demonstration farm has always been to help others learn and reconnect to nature and sustainable farm practices. To that end this article will highlight some of the more common questions we’ve heard from sprout producers.
What is the importance of seed quality?
Finding good grain to sprout is much like finding a good source for hay. Much like hay, the grain crop can vary from season to season based upon the climate and weather. When grain is threshed from the field there can be different qualities to the process of threshing too. So, what does a fodder producer want? High germination rates! Sometimes, however, the choice may mean paying a more premium price for the grain which may impact the cost effectiveness of sprouts in one’s feeding program. We always want to look for well threshed grain: grain that has all papery coverings or awnings removed and the hulls of the actual grain seed intact and undamaged. Having this excess chaff can mean extra vectors for molds as they start to decay during the sprouting. But beyond grain that is well-threshed, we get into discussions of seed quality. Grain seed intended for planting, or as actual “seed”, is usually referred to as “Seed Quality” grain and typically has some guarantee of germination rates. It is also better sorted to remove the smaller and more immature grains from the bunch. This is the type of grain that malters and beer makers want because they usually sprout it too. So, high germination rates become key when making a purchase. However, if sprouting for livestock, there’s still some options out there other than “Seed Quality” grain.
The next tier down is usually referred to as “Feed Quality” grain, and while usually passed up by those who would sprout, we find it worth considering, especially if it means saving some money. “Feed Quality” grains usually come with no germination rate or viability guarantees. It is usually intended for use crushed, cracked or feed whole to animals or included as an ingredient in pelleted food rations. Can it be used for sprouting? The answer is a qualified “yes”. First thing to consider is the age of the grain, sometimes “Seed Quality” grain becomes “Feed Quality” grain because it’s been sitting around for more than 2 years in storage, experiencing a natural decline in germination rates. Many times, the “Feed Quality” moniker is applied to freshly threshed, yet unsorted grain, because it still includes many of the younger, more immature grains along with those grains that reach full maturity upon harvest. “Feed Quality” grain can include more cracked or damaged grains too. So, if considering “Feed Quality” grains for purchase, be sure to inspect the grain and ask it’s age. If it is fresh and doesn’t contain an abundance of cracked or crushed grains, or grains that are off color (browned or showing signs of fungal damage), then it can be used for sprouting. The caveat to using this quality of grain is accepting the fact that there will always be some grains that will not germinate in the bunch. In our experience, we find that we can still produce very acceptable mats using “Feed Quality” grain as long as it is not too old. The ungerminated grain seeds still get consumed on our farm by the chickens who act as clean-up crew around the herd of alpacas.
We use a bleach pre-soak process for our grains and consider pre-sanitization of grains a necessity for the DIY sprouter. That’s not to say that one cannot sprout or avoid molds without pre-sanitizing the seed. Indeed in some commercial approaches, grain is simply spread directly into the grow trays and the system handles the rest. However, most DIY producers have difficulty achieving the same operational parameters that commercial turnkey systems can achieve, and molds have the advantage. Grain that is stored in any fashion is prone to storage mold spores, like Aspergillus. This is a very common mold that will look like fluffy white cotton (not to be confused with root hairs) if there’s an outbreak. By pre-sanitizing the seed, prior to introducing it to a grow tray within the grow system, we reduce the vector of contamination not only of this type of mold spore, but also of any other fungal spores that might be present, along with cleaning the seed of dirt and debris.
For a DIY producer, we want leverage over mold control from the very start of the growing cycle. However, the best pre-sanitized seed does not mean that molds cannot occur or will be prevented during the growing cycle. Upon germination, the seed hull is discarded by the newly emerging plant sprout. This seed hull immediately starts to decay. The style of irrigation can encourage or accelerate the rate of decay. Sprouting is a delicate dance between creating a live plant and controlling the decay rate of those discarded seed hulls where molds gain a toehold. During a grow cycle, many other factors can cause molds to occur within the seed bed: climate control, air circulation and evaporative rates, cleanliness, and mixed use applications. That last point deserves further consideration. Think of a sprouting application as a great room air filter: it’ll attract any and all mold spores in the room. This is why we highly recommend a dedicated grow room for sprouting and not placing a grow system in areas like kitchens, laundry rooms, or greenhouses with plants in dirt. We also recommend adding filters to cover any room air-intake vents. Pre-filtering the air will help keep spores from entering the grow room and settling into grow trays.
What about using an air-stone or bubbler to pre-soak my seed?
Some sprout producers approach the pre-soak sanitization by turning to an air compressor that bubbles air in the soaking seed instead of using a sanitizer, like bleach. It is important to note that there is some benefit to this approach, but it is not actually killing off or sanitizing mold spores. Basically what an air bubbler or air-stone does is add agitation to the soaking seed. This agitation is very effective at helping to scrub the seed clean of anything clinging to the seed hulls, thus thinking that the seed is sanitized. At a minimum, if using this approach without the addition of a sanitizing agent, we recommend an additional rinse with clean water to wash away anything that is now floating in the water. At best, when combined with a sanitizing agent, like bleach, an air compressor shooting air through the soak water and agitating the seed works great, but for a different reason than many would suspect.
When soaking seed in a bucket of water, not only are we trying to sanitize the seed hulls, but we are trying to trigger germination. This soak will soften the seed hull, naturally. If too much seed is soaking at once, then the risk is seed compression. The seed at the bottom of the bucket will get compressed by the weight of the seed on top of it, thus, will not germinate. With the addition of an air compressor agitating the seed, seed compression is greatly reduced or eliminated. So if considering an approach using an air-stone or bubbler, the key is having one strong enough to move and agitate the seed within the bucket so it does not settle.
Heat Release and Grow Room Temperature Management
If soaked grain were allowed to remain in a bucket to sprout, one would quickly find that a lot of heat is released during the process and the seed in the middle would be quite warm. This is due to the energy used when amino acids are being converted into proteins by enzymatic action. This heat release can become an influence around the temperature management of the grow space as well. It becomes important to place multiple temperature gauges near the grow trays in a grow system in order to obtain an accurate reading of the mean temperature fluctuations in the grow room. Simple digital gauges with remote sensors can be found which can be placed near the lowest trays, highest trays, the front and the rear of a growing system. Be sure to take multiple measurements near the grow trays when trying to discern what your optimal growing temperature should be. Also, record daily 24 hour high and lows in the grow room. While a consistent grow temperature is something many growers try to strive for, we try to mirror nature’s natural day to night fluctuations and allow for a +- 5F degree range both above and below the mean temperature we are striving to keep our room at. For our grow room, the average temp is kept around 60F degrees. This means we can see lows sometimes around 55F or highs around 65F. Typically the lows are occurring during our simulated night cycle when additional lighting is turned off.
In encouraging a plants sprouting cycle, not only are we trying to mirror a day and night cycle, but we are also not going to irrigate during the simulated night cycle as well. One important note is that roots need as much aeration as they need irrigation. For plants, root activity is greatest during the nighttime. Thus, by not irrigating during our nighttime periods, roots will naturally stretch and knit up into mats better as they search for water.
What’s the best grow temp for a Fodder Sprouting application?
There is no one best temperature to be sprouting at, and indeed a person’s best conditions will fluctuate with the changing seasons as well. What works as a best temperature for one sprout producer in the Pacific Northwest may not work at all for someone down in Florida or Texas. Local conditions matter. Instead, we encourage growers to keep good records of activity in their system to find that ideal “pocket of operation” that works best for them. For some, that may mean an average temp of 60F for others they may be able to sprout at 70F. Temperature does influence performance. Too high a temperature can cause more fermentation in a grow tray, reducing performance and germination. On the other hand too low a temperature can also impede germination rates. Higher grow room temperatures will experience faster grow cycles with grassy sprouts, but will be challenged to produce solid root mats. Lower temperatures will slow down a grow cycle but produce well knit root mats with good shoot growth, albeit not as grassy. Is either result better than the other? Not really. Remember we are going for a total protein package that includes both roots and shoots. Either route could potentially work for a grower, yet one may be more suitable for mold controls than the other based on local growing conditions, including the local yeast spores and lactobacilli that are present.
We record both objective and subjective observations on a daily basis. Our objective measures are in the form of temperature and humidity measurements. Our subjective measures include a 1–5 rating for each of the categories: germination, root mat structure, and shoots. We note any appearances of molds or poor performing mats and try to determine if an event is “incidental” or indicative of a “pattern” over time. For example, we had one grow tray that produced a poor mat. We made a note to watch the next mat harvested from the tray during the next grow cycle and discovered the same result was occurring. Once we determined this was a pattern, we put our thinking caps on and took a closer look to find that the irrigation line to that tray was blocked and thus the tray was not getting the same flood rate as all the surrounding trays. Sometimes these occurrences are incidental; a bad seed causing a fungal outbreak in a root mat. Sometimes it is hard to see a pattern at play in one’s system without recording some metrics to discern changes. By keeping good records, we are able to see seasonal changes and make adjustments to keep everything in balance, and in that “pocket of ideal operation”.
Be sure to check out these other Fodder articles and videos on our blog! We also sell the grow trays we made famous with our flood and drain style approach for DIY sprouting:
BONUS! Check out the photo album for some close-up shots of all aspects of our Fodder Room via our Facebook Page: https://www.facebook.com/media/set/?set=a.10151297013542962.496318.230401092961&type=1&l=a16cdb13b7