You may have heard someone describe tasty rosin as “terpy”. Terpenes are the flavor center of cannabis and many other plants. There are tens of thousands of terpenes so far identified in the world and around 150 so far identified in cannabis. [1,2] Many of the terpenes found in cannabis are found in fruits like mangos, herbs like oregano, and plants like hops.
Each terpene has different properties including flavor, smell, vaporization temperature, and potential medicinal benefits. Some terpenes/terpenoids like linalool may be associated with stress and anxiety relief while others may be more suited to focus and alertness like pinene. Cannabis testing labs are now even cataloging the terpene profiles of products so consumers can make more informed decisions about which product works best for them.
Some of the most common terpenes and terpenoids found in cannabis include myrcene, pinene, caryophyllene, limonene, terpinolene, linalool, humulene, ocimene, eucalyptol, geraniol, and farnesene. These terpenes can be found in varying levels across the plethora of cannabis varieties, each imparting its own contributions to the flavor and aroma of the plant.
Terpenes will volatize at different temperatures (their boiling points). Therefore, depending on your technique when pressing rosin, the flavor may change depending on which terpenes are still present after processing. In this article, we will cover some tips and tricks that can help you produce the tastiest rosin possible.
Preserving terpenes when producing rosin can elevate the flavor and effects of your end product. The trick, when pressing and post-processing flavorful rosin, is to avoid anything that may degrade labile terpenes. There are several factors that can lead to terpene degradation including heat, light, and oxygen.
Producing rosin does not require expensive lab equipment or dangerous, flammable solvents. This means that you can do it yourself in the comfort of your own home. To make rosin, all you need is some starting material, a rosin filter bag, a rosin press, parchment paper, a glass jar, and a dab tool. Whether you are pressing hash rosin or pressing flower rosin, terpene retention can make good rosin into great rosin. Below is a step-by-step guide to producing rosin that is filled with flavorful terpenes.
Fire in = Fire out
Fire in, fire out. It is a simple saying, but it’s 100% true. It should be no surprise that high-quality rosin comes from high-quality starting material. Flower should be properly humidified when pressing flower rosin. This is about 57-64% relative humidity and you can measure this with a simple hydrometer. If you are using dispensary-bought flower, the terpene content may be listed on the label (hopefully). Taking note of this can help you develop an understanding of which terpenes most appeal to you. If you are pressing hash rosin, the hash should be brought to room temperature before pressing.
Pack the Rosin Bag
Once you have your starting material, it’s time to pick a rosin bag. You’ll want to use a highly-durable rosin bag that can withstand the heat and pressure applied during a press without the bag “blowing out”. Gutenberg’s Dank Pressing Co rosin bags are double-stitched with top-quality nylon to provide you with an incredibly durable bag. (Use the code “terps15” on their website to get 15% off.)
The micron size of the rosin bag you choose has to do with your starting material. Flower rosin is best pressed in 90- to 220-micron bags. Hash rosin is best pressed in 15- to 75-micron bags. Generally, smaller pore sizes will yield cleaner rosin, but you may sacrifice some yield. The dimensions of your rosin bag are based on how much material you are pressing. For example, a 2×4-inch bag can fit about 7 grams of flower and 24 grams of hash.
With your rosin bag chosen, it is time to pack it with your flower or hash. For flower, it is best to remove the stems and break the buds into medium-sized chunks. Just don’t grind the flower.
Take your flower or hash and begin to line the bottom of the inside of your rosin bag. Be careful to avoid any air pockets as these can be troublesome. At most, fill the bag until there is about ½ inch of space left at the top. If there is more than ½ inch left, you can cut the remainder off and discard it. Fold this last ½ inch of bag over to “seal” the starting material inside the rosin bag.
Pro Tip: Start with a small amount of material for your first press. This is the “test press”. This way you can discover any issues without risking the loss of a lot of material.
Parchment Paper Party
It’s time to line your rosin press plates with parchment paper to catch the rosin. It is best to use thicker parchment paper that can withstand the heat and pressure that will be applied when pressing. We suggest using two sheets of parchment paper; one for the top plate and one for the bottom plate. Make sure the top paper is wide enough to cover the entire plate and long enough that it extends a few inches past the plates. The extra space is a precaution to catch any rosin that may expand further than expected. The bottom paper should be long enough that it can catch all the rosin that is about to be squished. It is not uncommon to see pieces of parchment over a foot long to handle the quantity of rosin being pressed. Many find it useful to make a fold along the sides of the bottom paper so it acts as a wall to block the rosin from running over the edge. Place your rosin bag in the center of the plates. Too far to either side and the rosin bag may expand over the edges of the plates when being pressed. This can lead to a blowout (broken rosin bag).
Folded Parchment Paper on Rosin Press Plates – Gutenberg’s Dank Pressing Co.
Set a Temperature
Now we are getting into the nitty-gritty of rosin pressing! The temperature you press at will have dramatic effects on the end product. Most people press between 160℉ (71°C) and 220℉ (104°C). Generally, the higher the temperature, the more a press will yield, but you may sacrifice some of the terpenes and, therefore, flavor. Lower temperatures may yield less, but the rosin may be tastier than the higher temperature counterpart.
Consistency-wise, higher temperatures may yield a more sauce-like product, but use a little extra time on the press and this can turn into a shatter-like product. Lower temperature presses tend to result in a more budder-like consistency. Keep in mind that the consistency may change during post-production curing. We will cover that shortly.
Rosin bag packed, parchment paper in place, temperature set. Now it’s time to crank that pressure up and squish some rosin!
To begin, we suggest applying just enough pressure to hold the rosin bag in place. Let it sit there for about 30 seconds to warm the material. You may even see it begin to “sweat” or look a bit wet. This is good! You should apply pressure with a steady, even increase for the duration of the press. There should not be any moments where the pressure is not increasing. This can burn away desirable terpenes.
How much pressure you apply and how long you leave your rosin bag on the press is determined by the temperature you are pressing at, what material you are pressing, and how much material you are pressing. Less time may be required on the press for higher temperatures than lower temperatures. Larger presses will require higher pressure to achieve maximum yields. Most flower rosin presses will not exceed three minutes and most hash rosin presses will not exceed two minutes on the press. It is going to take some experimentation and practice to really dial in what works for you. Each cultivar, and even each bud, will press differently, so don’t get discouraged and just keep at it!
- Let the rosin bag sit on the heated press with minimal pressure for about 30 seconds to let it warm up.
- Apply pressure with a steady, even increase.
- Avoid moments when you are not increasing pressure.
- Less time may be required for higher temperature presses than those operating at lower temperatures.
- Larger quantities may require higher pressures to achieve maximum yield.
- Flower rosin generally requires longer on the press than hash rosin.
Note: this is completely optional step and some people prefer to enjoy rosin freshly pressed.
Curing rosin is the act of introducing temperature differences, oxygen, time, and agitation to the product. The consistency of your rosin can change dramatically with a cure. Even the terpene profile of your rosin can alter. To begin, immediately collect the rosin from the parchment paper post-press and get it into a glass, airtight container. If the container is not airtight, then oxygen will get in and that can break down terpenes.
Next, place the rosin in either a cold or heated environment, depending on your desired consistency. This could be your refrigerator, a dark closet, a hot plate, an oven, etc. Cold cures (about 45℉ to 70℉) tend to form the rosin into a more badder-like consistency. You may see puddles begin to form during the cure. These are mostly terpenes and they are loaded with flavor. Some choose to use a dab tool to “whip” the rosin and homogenize the mixture, giving a light, fluffy consistency.
Heat cures (about 90 to 220℉, 32 to 104°C) usually result in a more sauce-like consistency. Which cure technique develops better flavor is up for debate. As we mentioned, each cultivar will press (and cure) differently.
How long you cure is really up to you. This could be 12 hours or a month. Generally, the colder the temperature, the longer a cure may take. For cold cures, periodically check the rosin and look for those terp puddles. When you see signification separation, try whipping it. If you are happy with the consistency then that may be the end of the cure. For heat cures, you may see the rosin begin to bubble. The longer it bubbles, the more saucy it will become (usually).
Pro Tip: Let the rosin come to room temperature after a cure before opening the jar and exposing it to oxygen. This can help retain some of the more volatile terpenes.
It’s best to store your rosin in an airtight, glass jar. Silicone may absorb some of the cannabinoids and terpenes over time and no one wants that for their hard-earned rosin! Keep the jar in a cool, dark place, away from direct sunlight. Light can degrade terpenes you just worked so hard to retain. We do not suggest storing rosin in the freezer as this may introduce unwanted moisture. Water and oil certainly do not mix, so it is best to avoid the freezer.
Dab time!!! It’s finally the moment when you get to enjoy the fruits of your labor. To taste the full flavor of your rosin, avoid dabbing at too high of a temperature. Many desirable terpenes will burn off 300 to 450℉ (149 to 232°C) range, so you want to dab at as low of a temperature that you can while still being hot enough to fully vaporize the dab. Larger dabs will require you begin dabbing at higher temperatures to fully vaporize the dab. Some say you need to “waste it to taste it” as in dab at such low temperatures that some of the dab does not get vaporized. This seems a bit excessive to us, but to each their own! Now go and enjoy that tasty, terpene-filled rosin!