Making solventless rosin may be a relatively simple process, but there are still plenty of things that can go wrong. One of the most common problems encountered by rosin makers is the “blowout”. A blowout occurs when your filter bag ruptures during the pressing process, allowing unwanted plant material to mix in with your rosin, which will ultimately ruin your end results. 

There are a number of factors that can contribute to a blowout occurring, and most of them are the result of poor technique. So, if you’re suffering from regular blowouts, here’s everything you need to know in order to solve the problem once and for all.


Depending on the size of both your press and filter bags, there is only so much you can pack into them. And so, many blowouts occur simply because too much starting material was placed into your filter bag to begin with. 

If you’re encountering regular blow outs, first try to reduce the amount of hash or flower that you’re using, because shaving off a few grams may just solve the problem. Also be sure to check the packaging of your filter bags, because a recommended gram amount should be listed there.


Pre-pressing is an often overlooked part of rosin making, but it can go a long way to ensure blowouts don’t happen. And it’s all down to making sure your starting material is evenly distributed throughout your filter bag before you press it. 

This is important because if there is too much in one side of your bag as opposed to the other, then the overloaded side will create a high pressure point that will massively increase the chances of a blowout occurring. It’s well worth investing in hand press like our RTP Pre-press Mold, because they’re specifically designed to squeeze your loaded filter bags into a perfectly distributed rectangle. That really helps to avoid a rupture when it comes to the main press.

Double Bagging

Another simple way to avoid a blowout is to use two filter bags at the same time, or “double bag” it. The extra bag can give you added security to press without fear of a blowout because if one bag does happen to fail, the other one will be there to save the day. 

Many commercial pressers utilize double bagging as a preventative measure, because even with perfect technique and top flight equipment, there will always be a small chance of a blowout occurring. Additionally, if you do give double bagging a try, make sure the seams of each bag are on the opposite sides to one another, this should guarantee maximum structural integrity. 

Pressure Build Up

What’s absolutely critical to a good press is the slow application of pressure. It’s important not to slam your plates down hard and fast because that’s a surefire way to rupture your filter bags. 

Low and slow is the name of the game. Bring your plates down onto the bag gently and then incrementally increase the PSI until you are at pressing strength. Sudden large jumps in pressure will easily weaken filter bags, so be patient! It will go a long way to halting blowouts in their tracks.

Filter Bag Quality

Ok, so you’re already doing everything listed above and still getting blowouts? Then it’s time to look at the quality of the filter bags you are using. We all love a bargain, but unfortunately you get what you pay for in this life, and filter bags are no exception. 

The cheapest offerings out there often simply don’t cut it, and likely can’t deal with the amounts of heat and pressure that are required for pressing rosin. If you’re technique is solid but you’re still having problems, then you seriously need to consider purchasing higher quality filter bags. 

Build quality and robustness of the materials used matter greatly, and because of this, we’ve created our own line of premium seamless filter bags that will hold strong under heavy pressure. 

Hopefully by following our advice, you can eradicate the scourge of the blowout. Just pay attention to correct technique, use good quality equipment and filter bags, and you should see a vast improvement to your solventless game.