The Science of Sifting

The Science of Sifting

Posted by Custom Cones USA on Jun 3rd 2021

Commercial sifters are changing the game for commercial pre-roll production.

In the past, we have written a lot about the end-to-end pre-roll production process to make sure you have a comprehensive, 30,000-foot view of the entire order of events to make the very best pre-rolls. For this post, we are going to focus on the sifting portion of the process to examine why exactly sifting is helpful, plus we run our own sifting experiment to see if those benefits play out in an actual production environment.

As the official Pre-Roll Experts of the cannabis industry, we never sell any pre-roll production equipment that we have not brought into our facility and tested ourselves to deeply understand how they work. So, we can say without hesitation that our sifting machines are a secret of the pros.

The sifting step removes any stems that got through the grinder along with any other foreign material or large particles that might break your cones when you go to fill them. It's a simple step but one that is often overlooked and can often lead to uneven broken and overall poor-quality pre-rolls.

Even more important than removing stems from the material, the sifter helps ensure an even particle size distribution across the ground material. That means that each individual particle is a similar size to the next particle.

Particles and Flowability

So, beyond filtering out stems and foreign materials, how does sifting help in pre-roll production? Scientists who studied the effect of particle properties on the flowability of ibuprofen powders found that, for powders with a narrow size distribution, the flow ability increases significantly with the increase in particle size.

When we provide a grind which is not a fine powder and we ensure that the ground material has a narrow particle size distribution, we will see improvements in flowability. Therefore, it is extremely important to be focused on your particle sizes and the distribution of particle sizes.

I want to emphasize this point with this quote from the KONA Powder and Particle Journal: "Any manufacturing operation that uses powders as one of its raw materials will always find one of its bottlenecks is cohesive powder flow."

By controlling the size of our particles through our grind and narrowing our particle size distribution through our sifter, you can create a free-flowing powder, which will allow you to make pre-rolls that are well packed throughout from crutch to tip. Not only will you make better pre-rolls, but you will make pre-rolls faster.

The Numbers Don't Lie

As an example, if you were to fill two pre-rolls: one with sifted material and the other with un-sifted material, you can really tell the difference. And when this is done across 169 pre-rolls (using a King Kone filling machine), the numbers don't lie.

We did a run with un-sifted material and the weight variance was 65 percent higher than the sifted material. The number of pre-rolls that had a hole due to stems was 488% higher than the sifted material. The number of pre-rolls with an unsatisfactory pack was 194% higher than the un-sifted material.

Watch the video!

What does this all mean?

Out of a run of 169 pre-rolls, you will get 27 more pre-rolls when you use sifted material versus un-sifted material. When you start to think about scaling up your production, the value of a sifter becomes clear.

For the purposes of our experiment, we used our QuickSift Mini, but you can also purchase two larger-size sifters: the Quicksift Commercial and the QuickSift Industrial, which easily accommodate larger volumes. Each of them can be purchased with a variety of different mesh screen sizes to get exactly the grind consistency you want.

If kief collection and application is part of your production of infused pre-rolls, then sifters can help you out there as well. You can get much finer mesh screens that are specifically designed for kief extraction, a process that separates the cannabis trichomes from the plant itself. From there, the kief can be used in a variety of ways. It can be made into a dry-sift live resin or you can apply it to the outside of your pre-rolls, using hash oil as an adhesive.

As we have shown, sifting the cannabis that goes into your pre-rolls is a step that not many care to observe and I guarantee it shows through in their end product. And it’s no coincidence. Particle size and particle distribution have a scientifically proven impact on the flowability of air through the pre-roll. Sifting is a small step in the process but it can add tremendous value for the use of your product.


Commercial sifters are changing the game for commercial pre-roll production.