Top 5 Common Mistakes When Pressing Flower Rosin


Todde Philips

🇺🇸 Retired veteran, father, rock-climbing expert & rosin connoisseur.

Pressing dried and cured cannabis flowers is a great way to get started in the world of solventless extractions. With a few buds, rosin filter bags, and a simple press (even a hair straightener will work), you can make dabs quickly and easily at home. Although pressing bubble hash yields a higher quality rosin overall, squishing flowers can still yield some impressive results. 

Cannabis flowers are accessible, relatively low cost, and don’t require multiple steps of processing before squishing. Flowers can give new extractors a feel for pressing rosin. Rather than pressing premium loose resin to make hash rosin, it’s better to make mistakes with less costly and more easily replaceable starting material. 

Read more about the differences between hash rosin and flower rosin in our article Flower Rosin vs Hash Rosin.

Pressing flower rosin is straightforward, but there are some potential pitfalls to keep in mind. Let’s look at the most common mistakes made when pressing flower rosin.  




1. Grinding The Starting Material

A common misconception for new extractors is that cannabis flowers need to be finely broken apart, with a grinder for example, before getting packed into a rosin bag for squishing. Using a traditional grinder as you would for preparing flowers to roll in a joint is actually counterproductive for pressing rosin. Grinding cannabis knocks trichomes off the flowers, which reduces rosin yield. 

Break flowers down into small, popcorn-sized chunks of bud. Remove the large stems and any excess trim leaves. Try to keep sizing between pieces of material consistent. 

2. Incorrectly Packing The Rosin Bag 

Packing too much flower into the rosin bag can lead to blowouts, which is when a rosin bag breaks open during extraction. The bag should be firm when it’s fully packed, but not rock hard. The rosin needs some space to flow through the material and out of the filter bag. 

Another common mistake with packing rosing bags is not filling in the corners of the bag. Empty corners of the rosin bag will trap rosin, so it’s important to ensure the flower gets pushed fully into the corners of your rosin bag. Be sure to use a poking tool and get pieces of bud all the way into the corners, which eliminates pockets of filter bag material that can catch rosin. 


Read more in How To Pack Rosin Filter Bags.

3. Pressing Flower with The Wrong Moisture Levels

There is a sweet spot for moisture levels when pressing flowers. Too dry and the material will actually re-absorb rosin as it’s extracted, which reduces overall yield. Too wet and you’ll have excess moisture in your rosin. 

Aim for 60-65% relative humidity in cannabis flowers for pressing rosin. We can get a reading of the relative humidity by placing the buds in a sealed jar with a digital hygrometer. 

If the flowers are too dry, there are several ways to rehydrate them, including with rehydrating stones or a wet piece of paper towel. Learn more in the article How to Rehydrate Dry Cannabis Flower For Rosin Pressing

You can also read more about moisture levels for starting material in the article What's the Optimal Moisture Content for Pressing Flower Rosin?

4. Not Preheating

Preheating flowers after they’ve been broken down and packed into rosin bags is key to getting the best results at the press. Preheating gets the trichomes primed to liquefy and break open during extraction. This allows trichomes to easily release the oil inside, which flows out as rosin. Without a good preheat, the trichomes won’t be ready to release their resin as heat and pressure are applied. 


To preheat the material, place the loaded rosin bag in between heated rosin plates and gently squeeze the material between the plate. There should only be enough pressure to hold the bag in place and ensure that heat is applied evenly to the material. Around 30 to 45 seconds is generally enough time for preheating.   

Read more about preheating in the article The Importance of Preheating When Pressing Rosin.

5. Uneven, Lumpy Rosin Bag

Rosin bags packed with starting material, often referred to as pucks, should be smooth, uniform, and consistent. Uneven, lumpy pucks can create an environment where rosin does not flow out steadily and consistently. If the buds are not broken into the same size pieces and packed into the bag evenly, the resulting puck will be bumpy and irregular. 

Once the rosin bag is packed evenly with material that’s broken into similar-sized chunks, pre press the puck using a pre press mold. Pre press molds allow extractors to compact the material once it’s in the rosin bag, preparing it for the press. 

Learn more in How To Use a Pre-Press Mold.


Unlike other extraction techniques that utilize chemical solvents and closed-loop systems, the process of pressing flower rosin is straightforward, simple, and easy to accomplish with a limited budget. Compared to other types of starting material like bubble hash for pressing rosin, flowers are a low-cost way to learn the ins and outs of rosin extraction. 

Keep in mind these common pitfalls to avoid, and you’ll save yourself some headaches and wasted material. At the same time, making mistakes is just part of the process. Sometimes your mistakes provide the most valuable lessons. 

Also check out these articles about pressing flower rosin:

How To Press Flower Rosin Starter Guide
Top 5 Rosin Pressing Tips for Flower

Happy Pressing!

Thoughts? Let us know by joining our secret Facebook group. Hang out with a community of like-minded solventless heads like yourself. Ask our head extractor questions, share your latest press and learn from hobbyists and experts in the industry.


What is flower rosin?
Flower rosin is rosin that's created from pressing dried and cured cannabis flowers. 

What is preheating starting material for pressing rosin?
Preheating starting material for rosin means warming up the material within rosin filter bags between the heating rosin press plates before applying full pressure during extraction. 

What is the best moisture level for pressing flower rosin?
60-65% relative humidity is the best moisture level for pressing flower rosin. 

Should you grind flowers before loading them into rosin bags for pressing?
No, you shouldn't use a grinder to break down flowers before pressing rosin. Just use your fingers and/or scissors to break apart the flowers into popcorn-sized nugs before loading into the rosin bags. 

Why should you pre press flowers before pressing into rosin?
Pre pressing flowers helps keep the puck even, smooth, and consistent before pressing, which helps to maximize yields. 


Leave a comment

Please note, comments must be approved before they are published


Access Denied

You do not have permission to view this page