What's The Problem with Using Dry Ice for Dry Sifting?
Cannabis enthusiast and student of the art of solventless extraction
Dry ice is the solid form of carbon dioxide, capable of achieving temperatures much lower than that of regular ice. Unlike water ice that changes from a solid to a liquid when it melts, dry ice sublimates as it warms up, meaning it changes from a solid directly into a gas vapor. This vapor cools the surrounding environment, which makes dry ice an effective cooling agent. At more than 100 degrees below zero, dry ice gets so cold that it can actually damage unprotected skin.
One of the mantras often heard when working with solventless cannabis extracts like bubble hash and dry sift is “keep tools and environment cold”. Cold temperatures allow cannabis trichomes to become brittle, and for the trichome heads to more easily separate from their stalks. But in the case of dry ice, too much of a good thing can prove detrimental. While cold temperatures make cannabis trichomes and the resin therein easier to work with, extremely cold temperatures like dry ice creates brings with it some significant downside.
Let's look at why some extractors use dry ice for making dry sift, and some unintended consequences that they often encounter.
One use case for dry ice in solventless production is for making dry sift. Dry sift is a form of extract made by working dry cannabis material over a set of mesh screens, or sieves. Similar to the concept of ice water extraction, where trichomes are filtered out of ice water using a series of bubble wash bags, the process of dry sieving isolates only full mature trichome heads from cannabis starting material like whole flowers or trim leaves. While washing hash involves ice water to keep everything cold and induce trichomes to separate from the material, dry sieving does not have this advantage. Instead, the ambient air temperature is as cold as the material will get.
Therefore, some extractors make the ambient air extra cold with the use of dry ice. As the dry ice sublimates, it makes the air around it extremely cold, which freezes the cannabis trichomes allowing them to easily fall away for collection. This in turn leads to higher yields of dry sift, as the frigid air causes more trichomes to drop away from the cannabis material.
Read more about the full process of making dry sift in The Ultimate Guide To Dry Sift.
The Problem with Using Dry Ice
So what’s the issue with using dry ice for making dry sift? We know that dry ice will increase dry sift yields, but it comes at a significant price. Dry ice can greatly reduce the quality of your dry sift due to excessive contamination.
Just like the dry ice makes trichomes brittle to easily fall away from the plant material, it makes the plant material itself extremely brittle and prone to shattering into tiny pieces. As the material is sifted over the sieving screens, it crumbles into microscopic particles of plant matter which is incredibly difficult to clean from the final product.
Dry ice also increases the likelihood that the entire trichome stalk will separate from the plant material, not just the head. Ideally, we want to only collect the heads. The trichome stalks are another form of contamination that often end up in dry sift that's made with dry ice.
Let’s take a look at dry sift that’s been contaminated due to dry ice.
Here we can see a lot of plant matter, and also trichome stalks.
The green hue in this dry sift is the sure sign of excess plant material contamination.
Another clear shot of contaminated dry sift.
Greater yields are appealing to every solventless extractor, but yields at the expense of quality aren’t worth it. While you can definitely increase dry sift yields with the use of dry ice to cool the temperature of the material, you’ll be left with a chlorophyll-ridden product. We can clearly see the evidence of excess contamination in the pictures above.
Therefore, we strongly recommend against using dry ice for making dry sift.
What’s your experience using dry ice when making dry sift? Let us know in the comments!
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FREQUENTLY ASKED QUESTIONS
What is the benefit of using dry ice for making dry sift?
Dry ice makes trichomes extremely brittle so they readily break away from the plant material, which in turn increases yields. But this comes at a price.
What is the problem with using dry ice for making dry sift?
The problem is contamination. Dry ice makes plant material very brittle and susceptible to shattering into microscopic pieces that is hard to separate from the trichomes.
Is it okay to use dry ice when making dry sift?
We don't recommend using dry ice for making dry sift, due to the high levels of plant contamination that it causes in the final product.
How can you keep things cold for making dry sift without using dry ice?
Working in a room with an air conditioner turned all the way down should bring temperatures to around 60 degrees Fahrenheit, which is cool enough for making dry sift.
Can you clean dry sift that's contaminated with plant material from using dry ice?
You can clean remove some of the plant matter contaminate using the Static Tech method. Read more about Static Tech in The Ultimate Guide to Dry Sift.
Is there any danger of using/smoking the dry ice kief . Do you need to decarbinate the kief or heat and press it?