You’ve got a new grinder, and you find a recipe for a light roast coffee. It says to set your grinder to 15, so you do that, brew the coffee and it tastes awful. What went wrong?
It’s not the coffee beans, the coffee brewer, or your brewing method. The issue is that the numbers on your grinder don’t mean anything. A common problem beginners face is figuring out how to adjust the grinder to find “true zero.”
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If you do not know where the burrs touch, it is going to be hard to grind coffee correctly. Let’s change that.
The Myth of the Factory Dial
I test a lot of coffee gear. Many beginners complain that they cannot replicate the results seen online. They think their brewing technique is wrong, but that is often not the case. The “10” on your grinder is probably a “14” on mine due to manufacturing tolerances and the vibrations during shipping.
When a manufacturer stickers or engraves a number onto the adjustment collar, they give you a reference point that you can use in your kitchen. This is not an absolute measure of the distance between the burrs.
To follow a recipe, you need to know where to start. That is “true zero.”
What is True Zero?
“True zero” is the point on your dial where the inner and outer burrs touch.
After you find true zero, counting steps or clicks becomes much easier. Recipes are easier to follow when you can say “15 clicks from zero” than “setting 15.”
How to Find Your True Zero (The Chirp Test)
Finding true zero is simple and doesn’t require tools, only your ears.
- Empty the grinder completely. Remove all beans from the hopper. Run the motor and use a bellows or a brush to clear out any retained grounds. The burr chamber must be empty.
- Turn the motor on. Let the grinder run empty.
- Adjust finer very slowly. While the motor is spinning, slowly turn the adjustment dial toward the finer settings.
- Listen for the chirp. Eventually, you will hear a high-pitched, metallic chirping sound. This is the sound of the burrs just barely kissing each other.
- Back off immediately. As soon as you hear the chirp, turn the dial slightly coarser until the sound stops.
You should listen for clicks, as true zero is just before one.
What to Do With This Information
After you have true zero, you can start making steps on how to adjust your grinder.
Some grinders allow for easier recalibration; all you have to do is loosen a set screw, adjust the number dial to be aligned with the click point, and retighten it. If this is possible on your grinder, do it so that daily changes are easier.
If your grinder dial is fixed and your click is at setting three, you will have to use mental math from there. Setting 3 is considered zero. If a recipe tells you to grind 10 clicks from zero, you should set it to 13.
Common Grinder Calibration Types
| Grinder Model | Adjustment Style | Can You Move the Dial to Zero? |
|---|---|---|
| Baratza Encore | Stepped Collar | No (Requires internal shim adjustment) |
| Fellow Ode | Stepped Front Dial | Yes (Remove faceplate to recalibrate) |
| DF64 / DF83 | Stepless Collar | Yes (Move the metal indicator arrow) |
| 1Zpresso Hand Grinders | Top or External Ring | Yes (Varies by specific model) |
Stop Guessing
While many coffee brewers argue about these tiny inaccuracies, many home brewers are suffering due to the five click offset from the factory calibration of their grinder.
Remove coffee from your grinder and this weekend, listen for the click, and create your baseline. With true zero, you’ll have control of your extraction and no longer need to guess.
Aromaster Stainless Steel Burr Coffee Grinder
Check PriceFrequently Asked Questions
Does the chirp test damage my burrs?
No, as long as you do it carefully. Coffee burrs are made of hardened steel. A brief, light touch at low RPM will not dull them. Just do not crank the dial down hard and leave it there.
How often should I check my true zero?
You should check it whenever you deep clean your grinder, remove the burrs, or notice a sudden shift in your extraction times. Normal daily use does not require constant recalibration.
Why does my zero point change after cleaning?
Coffee oils and micro-fines build up in the threads of your adjustment collar and under the burr carrier. When you clean those out, the burrs can seat slightly closer together, shifting your zero point.
