How to Clean Your Grinder: A Step-by-Step Guide

Herb grinders stand on the frontline of a successful vape or smoke session. They’re a lifesaver when prepping marijuana or hemp flower, and an important investment before exploring the leafier side of cannabis products. Pre-ground bud won't always taste fresh, and using your fingers to break sticky buds is messy.

Keeping your grinder clean ensures that it performs at its peak. Residue builds up quickly with regular vaping, and the more of it there is, the harder it is for a grinder’s teeth to... well, grind. You can’t get the most out of your weed vaporizer with a dirty grinder. 

Whether you’re tackling months of buildup or scrubbing down your grinder after a single session, here are a few ways to handle cleanup.

What is a cannabis grinder?

It’s in the name: you use a grinder to grind up dried-and-cured cannabis flower. Both hemp and marijuana users should always keep one on hand, though you may want to clean yours often if you’re switching between the two. High-CBD bud and THC-rich marijuana have very different effects.

Smokers aren’t the only ones who benefit from a high-quality metal, wood, or acrylic grinder. You’ll also need one if you use a vaporizer or dry herb pen, since you can’t exactly pack a bowl without grinding your bud first. Even recipes for homemade edibles (brownies, cannabutter, etc.) may require ground and decarbed flower.

Breaking weed apart by hand—or using a makeshift tool like scissors—can work, but it’s tedious at best. Plus, you’re sacrificing a clean grind, meaning flavor and potency could suffer. 

Types of cannabis grinders

Classic grinders have two pieces: a top and bottom half, both with pegs or teeth. Nothing fancy, but enough to get the job done. Simply break the bud into smaller chunks, place them on the teeth, and twist. You’re then ready to load your vaporizer. 

More advanced grinders have three or more layers. Kief catchers are a popular addition since they allow users to collect pollen-like kief (aka trichomes), a potent byproduct of the grinding process. You can repurpose this powder later.

Grinders come in a range of materials. Metals (stainless steel, aluminum, or zinc) are common, though you can also find plastic or even wooden herb grinders. Plastic or acrylic grinders tend to be the most affordable. 

Why should you clean your weed grinder?

No one wins with a dirty grinder. Whenever you go too long without giving it a wipe or a soak, residue and other plant leftovers build up—which can have major consequences.

For one, with residue coating and obstructing the grinder’s teeth, uniform grinds just aren’t happening. Clumping is a huge concern when you rely on an dirty cannabis grinder. Weed doesn't heat up uniformly when it clumps, leading to poor flavor, aroma, and potency. Not a fantastic start to any session.

You don’t want your grinder to get moldy, either. Bud is an organic material and can attract bacteria, especially if it’s left in warm, cramped quarters for extended periods. It’s easier to clean a grinder regularly than it is to save one you’ve neglected for years. 

How often should you clean a grinder?

While it’s typical to put off grinder cleanings (no judgment), the habit is nice to have.

How often you clean your grinder depends on how you use it. First off, are you packing just one bowl per session, or do you grind enough weed for several? Do you pull out your herb vaporizer every night or once in a blue moon? The more bud you grind, the more often you’ll need to freshen up your grinder. 

There really isn’t a formula beyond that. Casual weed users may be able to go a few months without freshening up. But in general, regular vapers benefit from giving their grinders at least a monthly wash. 

Don’t let a dirty grinder sit untouched for months on end. Again, this invites mold and bacteria growth. Doubly so if you store your grinder in a warm, humid environment.

What tools do you need to clean a grinder?

You can’t clean a grinder by sheer force of will. To make your life easier, gather a few household tools before getting started. Deep cleans will require the most resources.  

At a minimum, have on hand:

• Isopropyl alcohol (at least 70%, ideally 90%+)
• Dish soap (for plastic grinders)
• A firm toothbrush or cleaning brush 
• A large container (Tupperware, plastic bag, or jar) 
• A plate or bowl
• Clean water
• A towel

An airtight container is also useful if you’d like to store kief for later. 

That’s often more than enough for a good cleaning... but if you’re hoping to remove layer upon layer of gunk and oils, you might need:

• A freezer
• A toothpick or soft-bristled brush

Others prefer to boil their grinders, in which case you’ll need a stovetop, pots or pans, and a pair of tongs. You can also badly damage some grinders this way, so be careful.  

Play it by ear—if you’re laboring over stubborn residue, change your approach. 

How to clean a metal grinder: easy mode

We're starting with the easiest method, but it’s worth taking your time and being thorough. Even a simple soak and scrub can clear away most or all leftover residues. 

Let’s focus on metal grinders for now. Plastic and wooden grinders have unique limitations, so be careful not to damage them along the way. 

Disassemble and empty your grinder

Grinders have two or more pieces. To cover the most surface area, make sure to disassemble them fully (including removable screens) at the start of each cleaning session.

You’ll also want to empty out leftover kief or loose materials. Pour this into a bowl or onto a plate for now, but when you have the chance, move it into an airtight container. This will help keep your kief fresh for longer. 

Consider repurposing these leftovers later. Kief can top your next bowl—just sprinkle it onto the ground bud before heating your portable or desktop vaporizer. Or, if you have extra time on your hands, use it to coat homemade CBD moon rocks. 

Like unground bud, avoid storing kief in sunlit, humid conditions, and don’t let it sit around for a year or more. Just because it’s highly concentrated doesn’t mean potency loss isn’t a risk.  

Soak your grinder in isopropyl alcohol 

Metal grinders can be soaked in isopropyl alcohol. You’ll want at least 70%, but 90% (or higher) isopropyl does an even better job at battling residue and bacteria. 

Fill a large jar or plastic bag with enough alcohol to submerge all components. Then, drop in each section of your grinder and keep them there for at least 30 minutes; you may need an hour if the grime is extra stubborn. Periodically shake the container to help break down residue. 

Scrub your grinder with a brush

Pour out the alcohol and remove each part of your grinder. While the remaining grime is still damp, begin scrubbing it away with a stiff or heavy brush. It should be loose enough to remove without too much trouble. If not, try soaking for a bit longer. 

Rinse and dry your grinder

After scrubbing, give our grinder a good rise with warm water to clear away whatever’s left of the plant material. Set all parts of your grinder on a towel to dry. 

Be patient and hold off grinding until the parts are fully dry—damp flower won’t grind cleanly. To add insult to injury, moist bud can stick to your grinder’s interior and dirty the freshly scrubbed surfaces.