Warm curing is known to bring about some drastic changes in the texture and consistency of rosin. A variety of the Jar Tech Method of curing rosin, warm curing involves placing rosin into a sealed glass jar and exposing it to heat for several days. It doesn’t require any specialty equipment, even an oven will work just fine. But there are a few helpful tips to keep in mind when going for the warm curing approach. 

Warm curing follows most of the same principles as cold curing, but it leverages the power of heat to bring about changes in the look and feel, and even the taste, of rosin. For hash rosin, warm curing is the way to turn freshly-pressed solventless into jam or diamonds and sauce, a couple of highly-coveted forms of rosin. Heat facilitates a chemical reaction known as nucleation, whereby the THC molecules actually “crash out” of the rosin, forming small chunks of crystal-like structures that suspend in a pool of terpenes. Terpenes, lipids, and cannabinoids within the rosin interact in dynamic ways when exposed to heat and sealed within a closed environment. 

Much of the outcome with warm curing is strain-dependent, as with many of the methods used in solventless extraction. There is no surefire formula that works the same way for every batch of rosin. In addition to the cannabis cultivar being used, the type of material used to extract the rosin also plays a part in how it will respond to the cure. Hash rosin tends to respond better to the warm curing method than flower rosin. 

There’s a lot of variation possible in the warm curing technique. You could do a 2-3 hour cure at 200 degrees in the oven, or extend the cure to several days with the rosin placed on top of a heating mat. It’s all about keeping an eye on the rosin to gauge its current state, and then removing the rosin from heat once it’s reached the desired consistency. You can also open the jar and stir the rosin midway through the cure, then replace the lid and continue warm curing.  

Here are some basic pointers to keep in mind when using a warm cure to transform and enhance your freshly-pressed rosin. 

Best Tips for Warm Curing Rosin

#2 Use straight-sided jars for curing
A jar with straight sides from bottom to top makes rosin collection after the cure much easier. Tapered sides with an opening more narrow than the base of the jar makes maneuvering a dab tool for collecting the rosin a little more tricky.

#3 Minimize empty space in the jar
Try not to leave more than one inch at the top of the jar between the level of the rosin and the lid. Keeping the extra space at the top to a minimum is better for the curing process because it means less oxidation of cannabinoids. It also keeps terpene evaporation at lower levels. 1oz jars from Uline are ideal.

#4 Keep in a dark place while curing
Light degrades cannabinoids, so always cure in a dark space. If needed you can put the jars in an opaque container to block out the light while curing. A closet works nicely as well, and can provide a cooler space due to lack of windows (depending on the season and where you live!).

#6 Use your rosin press plates as a heat source
Setting your sealed glass jar between heated press plates is an effective strategy for warm curing rosin. No pressure is needed, just be sure the plates are in direct contact with both the top and bottom of the glass jar.

#7 Don’t overextend the curing time
As soon as you observe the desired consistency, it’s time to end the cure. As a general rule, heat increases the rate of degradation, so keeping exposure to heat down to a minimum is best.

#8 Use only the minimum amount of heat needed to reach desired consistency
Just like curing time, curing temperatures are best kept to the minimum needed to reach your desired consistency. Keep 200 degrees as the upper end of the spectrum. Even 100 degrees can be enough for warm curing. The only way to find the minimum temperatures needed is to experiment with different time and temperature settings. 

#9 Flower rosin often doesn’t respond as well to a warm cure
Hash rosin has a better ratio of lipids, cannabinoids, and terpenes for warm curing than flower rosin. Whereas flower rosin responds well to a cold cure, warm cure should be reserved for hash rosin. That said, hash rosin can also benefit greatly to a cold cure. It depends on which consistency you're targeting.

#10 Heat mats (like the kind made for clones) work well for a longer cure
Sometimes high heat inside the oven for a couple of hours is all that rosin needs to start crashing out and oozing terpenes. At this point you have a nice jam to work with. But sometimes a longer cure is in order, and with lower temps. In this situation, look to heating mats as a great solution for lower heat over a longer time period of curing. Leave the jar on top of the heating mat for several days, or placed between two heating mats to distribute heat evenly around the rosin. You can even recombine the rosin after it begins to separate, and then continue the cure. 

Conclusion

Warm curing can work wonders to transform your rosin into a jam or diamonds and sauce. It’s really phenomenal to watch terpenes pool together and cannabinoids crash out during the cure. And all this occurs thanks to the ratio of lipids, terpenes, and cannabinoids present in solventless rosin. With the application of heat we watch the magic of chemistry in action, and we can transform rosin into some unique and highly desirable consistencies, all without the use of chemical solvents. 

FREQUENTLY ASKED QUESTIONS

What temperature should I use for warm curing rosin?
Warm curing temperatures between 140 and 200 degrees Fahrenheit are common. Even 100 degrees on a heating mat can be effective. Play around with different temperatures and times to find what works best with your rosin. 

How long should I warm cure rosin?
There’s not one specific time that’s best for curing rosin. You can put rosin in the oven for a couple of hours, or keep it on a heat mat for several days. A combination of both approaches is also an option.

Can I use my press plates to warm cure rosin?
Yes, using your rosin press plates as a heat source for warm curing is possible. Be sure that the plates do not exert pressure onto the glass jar itself, but only rest on the top and bottom of the jar.

Does warm curing damage terpenes?
Warm curing speeds up the evaporation of terpenes, which is a good reason to keep the lid closed during the cure. Although terpenes will evaporate, they'll also stick to the sides of the jar in the process, so that they can be recombined with the rosin after curing.

Is warm curing better than cold curing?
One method is not necessarily better than the other. That said, if you’re curing flower rosin, cold curing may be the best approach, as flower rosin often doesn’t get the same desirable results with a warm cure as does hash rosin. If you’re working with hash rosin, warm curing can bring about some impressive transformations. Cold curing is also effective for hash rosin, which can bring about more of a badder-type consistency.