How to Grow Hemp for CBD in Wisconsin – Step 9: Oil Extraction

The major demand within the current CBD market is based around concentrated oil. Concentrates allow for a variety of different ways to get CBD into your body such as ingestion, topical treatments, and vaporization. The most common form of CBD oil is packaged in tinctures, which is what the following will touch on. There are many different ways to extract CBD and produce tinctures, so I’ll just be covering a rough outline of the method we use at the laboratory that I work in.

Extracting the CBD into a crude oil is the first step to making tinctures. Although there are solvent-less techniques, this is typically done by using solvents such as butane, pentane, hexane, propane, and isopropyl alcohol. When run through a pressurized extraction system, these solvents essentially attach to the flower’s present cannabanoids (CBD), and pull it from the plant matter. There are many factors that processors must confront to pull this off effectively, but going into detail would be an information overload and most likely require a whole separate blog series.

After the CBD infused crude oil is produced, this is ran through a series of distillation techniques involving heat and vacuum pressure to pull the leftover solvent from the product. From there, the refined oil is typically mixed with a high-fat vegetable oil. The fat lipids attach to the CBD molecules and activate them, making the end product safe for human consumption.

How to Grow Hemp for CBD in Wisconsin – Step 8: Processing for Flower

Cannabis flower high in CBD has hundreds of benefits. Although the majority of CBD products on the market today are produced using CBD oil, there is still a solid demand for the flower in smokable form. Those who smoke CBD buds report various positive effects such as (but not limited to); a reduction is seizures, inflammation, pain, and anxiety. The effects of smoking or vaping the flower are nearly instant, which is an added benefit as well. It should be noted that those with respiratory issues are prone to negative reactions in their lungs, just as with any smoke.

Growers who process their flower for smokable/vaping purposes first dry their buds properly after harvest. As stated in Step 7, curing the flower is highly suggested in order to take the product to the premium level. After the buds are fully cured, it’s time to break down the flower using a grinder. Once the flower is all ground up, roll a cigarette using hemp-based rolling papers. Reputable brands include RAW and Zig Zag. It’s also a good idea to use a filter, which is sometimes referred to as a crutch. This enables smokers to properly hold the cigarette without damaging its integrity. Selling your crafted smokes in packs of 5-20 has been a pretty lucrative plan for growers in the past. Also, many users enjoy the process of rolling their own, so just selling the ungrounded flower post-cure is also an effective business plan.

How to Grow Hemp for CBD in Wisconsin: Step 7 – Curing

After your hemp seems as dry as possible from the wire hanging described in post #6, it’s time to cure the flower, which ensures the moisture in the buds is fully released. You’ll know it’s time to cure when the small branches break with a snap instead of bending. While some growers overlook the curing process and push their flower straight to processing or wholesale, the most accredited operations use a prolonged curing method for its added benefits. These benefits include increased potency and aroma, along with a longer preservation time of the buds.

The first step to curing your flower is to separate the buds from the branches. After separation, trimming the buds of any leaves and stems will allow for full oxidization of the flower. This is a tedious process, but it’s recommended for any growers looking to produce the highest-quality flower possible. Once your buds are manicured, place them in any airtight storage vessel, such as a canning jar. The flower should be packed loosely to the top. Be sure not to compact any buds before sealing the container.

Trimmers prepare the hemp flower, or bud, to make it more appealing to consumers.

From there, place the containers in a cool, dark, and dry spot and leave them there for around 3-6 weeks on average, although a handful of strains require several months to be fully cured. Throughout the first week you’ll want to open the containers and let them breath for a couple minutes. You should notice your buds (which were crunchy when put into the curing vessel), are now a bit moist due to the reoxygenation. Red flags include the presence of an ammonia-type smell, which suggests bacteria is molding your flower, or overdried buds that are still crunchy. The latter is preferable, as it could still be partially salvaged via oil extraction, which will be discussed in the next post. Stay tuned, and thanks for reading!

How to Grow Hemp for CBD in Wisconsin: Step 6 – Drying

A location to dry your hemp should be determined before you even put plants in the ground. It’s a detail that could potentially be overlooked, but it’s of the upmost importance that the drying process begins immediately after harvest. The plants will be full of moisture once taken from the ground, so a proper drying facility is vital in order to prevent the plant material from molding. Structures such as a barn with a roof, walls and a large open space are ideal for drying.

Solid ventilation is very important, so hanging the floral biomass spaced appropriately along strings or set on open racks are the two most commonly used drying setups. Several industrial fans should be utilized during and after the plants are set up in the drying structure. The temperature in your drying space should sit somewhere between 60-70 degrees F, and a humidity of 60% should be maintained.

While some growers will rush through the drying process, this runs the risk of improperly drying the flower and leaves a chance that the buds will rot from within. Ideally, a slow-dry process with consistently high airflow will cure the hemp and produce and higher-quality product.

Farmers have found that hanging whole plants upside down on wires is inefficient, as the resulting closed umbrella shaped plants will prevent ventilation in the center. Due to this effect, growers are advised to dry individual branches of flower. Although this is a bit more intensive, it will pay off in the long run with properly dried biomass, and a higher market price.

How to Grow Hemp for CBD in Wisconsin – Step 5: Harvest

Timing is without a doubt the most crucial factor when harvesting your hemp crop. Growers must let the Wisconsin Department of Agriculture, Trade, and Consumer Protection know when they plan to harvest in advance. The optimal time to harvest is when your plants test high in CBD, yet still under the 0.3% THC threshold allowed by the state. Predicting when this optimal cannabinoid content will take place is a tough task. The following tips can help give you an understanding of calculating the proper date.

Although many farmers simply harvest after a set amount of days since first sprout, the top CBD farmers will track their grow with spreadsheets developed through testing plants along the growth phase. Getting your plants tested on occasion throughout the growing season may take time and energy, but it’s sure worth the reward. The more data you collect on your crop’s CBD and THC content, the easier it will be to predict this optimal date. With some basic algebra, growers can use this data to find the slope, and apply this slope to the calendar. Once the optimal date is determined, contacting the DATCP one month in advance will give them enough notice to have your fields tested prior to this date. It’s a safe bet to pull the harvest date back a week or so once you’ve calculated it, just in case the data is off.  If plants do run “hot”, or over the 0.3% THC limit, the state will force the whole field to be destroyed.

Beyond the harvest date, growers should be prepared for harvest with enough labor and equipment for the size of their fields. If your grow is on the smaller side (10 acres or less), hand cutting the plants at the root with machetes or loppers is your best bet. For large scale operations, some farmers use modified harvesters for crops such as corn to cut the plants off halfway up the stalk. This leaves the bottom half to decompose into the soil and replenishes many of the nutrients used during the grow. I hope this shed some light on the hemp harvesting process, stay on the lookout for the following step in this blog series; Drying.

How to Grow Hemp for CBD in Wisconsin – Step 4: Growing

Once your hemp plants are in the ground and begin to take root, it’s mostly a waiting game until harvest approaches. For crops that were planted with regular seed, identifying and removing male plants is absolutely key for a high-quality harvest. Growers who fail to do so will see an over 40% reduction in cannabinoids (CBD), and the pollinated plants will convert their energy from growing larger and more potent towards producing seeds. Pollinated crops will result in an over 25% loss in biomass, which is all the more reason to plant using feminized genetics.

As stated in earlier posts throughout this series, farmers looking to stay proactive during this time should investigate for any wildlife that may be harming their crop. Zero insecticides, fungicides or pesticides can be used since the chemicals will be converted into the plant’s oil profile and make the flower completely worthless. Insects can be an issue in certain areas, although the majority of Wisconsin growers have seen little threat from these pests so far.

If a drought occurs and there’s no irrigation in place, you should work out some sort of system to keep your plants watered. Stressed plants are proven to yield significantly less than those that aren’t stressed, so the overall goal during the growing phase is to provide as least a stressful environment as realistically possible. Aside from keeping your crop watered, I’d highly suggest investing in weeding equipment such as weed whackers, machetes, clippers, etc. These will be vital to keeping assuring the soil’s nutrients are going strictly to your plants. One common point of feedback from Wisconsin farmers who grew hemp in these past couple years is that it was much more labor than they had anticipated, so be fully prepared to work and/or have extra hands at your disposal.