Can You Re-Grind Coffee If the Grind Is Too Coarse?

 As we all know, the grind size and water temperature are determined by the characteristics of the coffee beans. The goal is always the same: to brew the best possible version of that particular coffee.

But sometimes, we forget to adjust the grinder and end up grinding a coffee that requires a fine setting with a much coarser grind.

This creates a problem: the coarse particles significantly reduce extraction efficiency. If you brew the coffee as-is, there’s a high chance it will taste noticeably weaker and less flavorful.
So naturally, people ask:
“Can I put the already-ground coffee back into the grinder and grind it again using the correct setting?”

Yes — you can!
In fact, at world-class coffee competitions, some competitors use a two-stage grinding method to increase particle uniformity. But before you jump in, you should know that this method comes with two major drawbacks. If you can’t overcome these issues, I actually recommend using another method to “fix” the incorrectly ground coffee — one that may help you brew a better cup with less trouble.

Drawback 1: Excess Fines

As you know, any grind produces a certain amount of fines — particles smaller than 0.25 mm. A moderate amount of fines can enhance body and complexity, but too many can easily cause clogging and over-extraction, resulting in bitterness and muddiness.

When you grind the coffee a second time, the fines increase significantly because the particles pass through the burrs again. The result? A much higher proportion of ultra-fine dust.
(You can usually see this clearly — re-ground coffee tends to have many clumps of fine particles stuck together.)

If your grinder already produces a lot of fines, I strongly recommend sifting the coffee after the second grind to remove some of them. This helps prevent common issues like clogging, slow drawdown, or harsh flavors.

Drawback 2: The Grinder “Eating” Coffee

Next, we need to talk about retention — what coffee lovers often call “the grinder eating coffee.”

Most electric grinders retain some grounds inside the grinding chamber and surrounding gaps. When grinding whole beans, you might put in 15 g and get out 14.7 g — that 0.3 g stays stuck inside.

But if you feed the grinder coffee grounds instead of beans, retention skyrockets.

I’ve tested this many times:
When re-grinding coffee grounds, nearly 20 g in becomes only around 13 g out. The rest remains in the grinder due to static electricity or getting trapped in dead corners.
To get it out, you’ll need to flush the grinder with beans (“bean purging”) or use an air blower to force the trapped grounds out.

If you're using a hand grinder, or if you have tools like an air blower, then re-grinding is still an option.
But if you have none of those, it may be easier to brew the coarse grounds directly and adjust your brewing parameters instead. With the right corrections, you can still make a delicious cup.

How to Brew Coarser-Than-Intended Coffee

(A Practical Fix Without Re-Grinding)

It’s simple.

Because the coarse grind reduces extraction, all you need to do is compensate by increasing other variables, especially water temperature and pouring technique.
Higher water temperature is easier and more intuitive to adjust than extending brew time.

Here’s an example using my recent roast on Taobao/Tmall —
Panama Elida Anaerobic Natural Catuai.

Adjusted Brew Parameters (for a grind that’s two clicks coarser than usual)

• Coffee dose: 15 g

• Brew ratio: 1:15

• Grind size: EK43 at 10.5 (normally 9.5), 70% passing through a 20-mesh sieve (normally 75–80%)

• Water temperature: 94°C (normally 92°C)

• Dripper: V60

• Total brew time: 2 minutes

Brewing Method (Three-Stage Pour)

1. Bloom:
   Add water twice the weight of the grounds. Bloom for 30 seconds.

   

2. Second pour (120 ml):
   Since the grind is coarser, water flows through faster.
   If you pour normally, the brew will finish too quickly, leading to under-extraction.
   So you must reduce the pour rate and draw large, slow circles to extend the extraction time.

   

3. Third pour (75 ml):
   Same small stream, but this time pour in tight circles the size of a coin.
   Let the water drain completely — total time should be right around 2 minutes.

The result?
A cup that tastes almost identical to the one brewed with the ideal grind setting — balanced, smooth, with a long and clean finish.
Flavors of berry, cream, and apricot all show up beautifully.

Final Thoughts

This example is just one way to handle unexpected situations.
If you ever grind too coarse, don’t panic — simply adjust temperature, flow rate, and pour pattern, and you can still brew a great-tasting cup.

Once you understand the logic behind extraction, even “mistakes” can be turned into delicious coffee.