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Why Jar Tests Are Obsolete and a Better Alternative

Why Jar Tests Are Obsolete and a Better Alternative

Written in collaboration with Apex Solventless

We're going through an interesting time in the hash space where we're transitioning from something that was largely done in the dark, to something that is done in fully licensed, state-of-the-art labs.

Show transition from really sketchy lab to state of the art new facility. Picture of old washing machine meme with a new cold room.

This is going to be an iterative article that we continue to update as best practices evolve. We're not here to push any specific brands or equipment. We are advocating for a data-driven approach to hash making and pheno hunting.


What's a "jar test" and how they started

Basement growers were wary of losing their entire crop to an unproven process when bubble hash first started making the rounds. It made sense at the time – mitigating risk by doing a "jar test" on a small sample of the live plant before deciding to freeze everything or dry it up and cure it.

Jar tests make sense when you're unsure of what your final end product will be, but if you're running a large scale solventless facility assessing resin yields, they don't paint an accurate picture of commercial viability.


What is a jar test?

A jar test is when a small sample of cannabis plant material is placed in a jar with ice water and shaken to loosely emulate the hash washing process, allowing for a visual assessment of its hashing potential.


Old techniques don't scale

Traditional caregiver market in Michigan typically involves large plants and small overall plant counts compared to their commercial counterparts. This means starting fewer seeds and having fewer phenos to select from.

As hash and rosin reaches commercial scale, it becomes even more important to have a streamlined process for testing large amounts of phenos... all while maintaining throughput and trying to catalogue a dense bank of knowledge you can use to build SKUs.

Bunch of different rosin tests from a commercial lab

Jar tests may work for determining what will make it into your personal stash, but it doesn't provide the data you need when pheno hunting at these scales.

At best, you get a visual estimation.

The traditional caregiver model of pheno hunting big plants discourages popping a lot of seeds and test washing -- despite that being the most sustainable way to scale. Without enough starting material, you're forced to assess while at the same time making production SKUs. Jar tests seem like a quick and easy solution, but you're basing potential for future yields off of an inconsistent visual estimation.

High-level issues with jar testing:

  • Doesn’t tell you head sizes they could all be outside of your ideal range

  • Your operating purely off of a visual estimation, and there could be huge variance between samples that look visually similar

  • You’re not mimicking the wash process or the agitation pattern that you’ll follow in actual production


Using data to make better SKUs

Tools that always work

A simple 8-gal clothing washer with the common hasher mods will get you very far. Whether you're switching to large scale hand washing or a machine after, it's a much more similar agitation pattern and allows you to test the sample across multiple washes.

We'll be updating this article with a guide on how Apex Solventless runs the mini washers for pheno hunts in the near future.

Larger sample sizes will always be a better representation of anticipated outcome if you decide to put it into production.

  • We recommend 300g-1200g of wet plant to determine accurate yields, but 600g+ is best

  • Simple plastic clothes washers mimic the agitation of larger machines much closer than other common small sample tests, ie jar test, or resin dial

  • Washing samples in a small washer does not take too much longer to perform than a jar test or Resin Dial

  • Apex Solventless has ran samples as small as 150g in a washer and captured meaningful data

More testing before going into production with a new cultivar

Tools that sometimes work in certain applications

Jar tests

  • Doesn’t give a quantitative measurement of any hash

  • No way to test quality of the output

  • Allows you to keep plant alive and turn into cured flower if it's not a yielder

Resin Dial

  • Allows for potential to be quantative, you can measure specific filtering screens/outputs to evaluate how specific micron ranges yield.
  • Potentially smaller processing size than jar test, which is good for requiring less starting material as an input, but doesn't help in terms of achieving accurate yield data. More starting material leads to yield numbers that scale more accurately into production.

  • Quick disclaimer: the Dial is not advertised as a way to get accurate yield numbers. It is advertised as a tool to help hashers see what their resin could look and smell like, which it does well. We're simply advocating for adding a layer of measurement on top of that if you're going to use one. 

We're all still learning

There's a million different ways to skin this cat. Hash makers are in a unique position, at the intersection of techniques that are thousands of years old and commercial viability. The key takeaway? No matter what you're making and what your scale is, data is your friend.

For small grows where space is tight, data can guide you into making the most out of every square inch. Large scale solventless may have the luxury of space, but data is still an integral part in maximizing efficiency while maintaining a large catalogue of genetics.

Big thanks to Apex Solventless for co-authoring this and being an early supporter. Here's where you can find them:

Apex_solventless_ 2.0



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