# How to Grind Coffee Beans

> Grind size by brewing method, why burr grinders beat blades, and what to do when you have no grinder at all — including where to get beans ground.

Topic: Brewing  
Published: 2026-08-29T09:50:00-04:00  
Updated: 2026-08-29T09:50:00-04:00  
Author: Mical Robert, Editor (https://trysix.online/author/mical-robert)  
Canonical: https://trysix.online/how-to-grind-coffee-beans

## The short answer

Match the grind to the contact time: fine as table salt for espresso, medium like sand for drip, coarse like raw sugar for French press. A burr grinder gives even particles; a blade grinder gives powder and boulders at once.

## Key takeaways

- Short brew, fine grind. Long brew, coarse grind. That single rule covers every method.
- Burr grinders crush between two surfaces; blade grinders chop at random. Evenness is the whole game.
- Ground coffee stales in days, not weeks — the surface area exposed to oxygen goes up enormously.
- No grinder? Most roasters and many supermarkets will grind beans for you if you say which brewer you use.

The grinder is the piece of equipment people buy last and should buy first. If your coffee tastes sour and thin one day and harsh the next, using the same beans and the same method, the grind is usually why. Here is how to match it to your brewer without guessing.

## Why grind size matters more than almost anything

Water dissolves material out of the surface of coffee particles. Halve the particle size and you roughly double the surface area for the same weight of coffee, so extraction happens about twice as fast. That is the whole mechanism.

Which means grind is not a preference — it is the dial that matches your coffee to the time your brewer gives it. An espresso machine has 25 seconds, so it needs a fine grind. A cold brew jar has 16 hours, so it needs a coarse one. Use espresso grind for cold brew and you will get something undrinkably bitter; use cold brew grind for espresso and water will run straight through.

> **The rule in one line** — Short contact time, fine grind. Long contact time, coarse grind. If your coffee is bitter, go coarser. If it is sour, go finer.

## Grind size by method

**Grind size, a household comparison, and the contact time it is matched to.**

| Method | Grind | Looks like | Contact time |
| --- | --- | --- | --- |
| Espresso | Fine | Table salt, slightly powdery | 25–30 seconds |
| Moka pot | Fine-medium | Between salt and sand | 3–5 minutes |
| AeroPress | Medium-fine | Fine sand | 1–2 minutes |
| Pour-over (V60, cone) | Medium | Coarse sand | 3–4 minutes |
| Drip machine | Medium | Coarse sand | 4–6 minutes |
| French press | Coarse | Raw sugar | 4 minutes |
| Cold brew | Coarse | Raw sugar, or coarser | 12–24 hours |
| Percolator | Extra coarse | Coarse sea salt | 4–6 minutes, recirculating |

If your bag says 'ground coffee' with no further description, it is almost certainly a medium drip grind — see [what is ground coffee](https://trysix.online/what-is-ground-coffee). That works acceptably in a drip machine and poorly everywhere else.

## Burr versus blade

A burr grinder passes beans between two abrasive surfaces set a fixed distance apart. Nothing exits until it is small enough to fit through the gap, so particles come out at a consistent size. A blade grinder is a small propeller in a chamber: it chops whatever it hits, repeatedly, and what you get depends entirely on how long you run it.

The consequence is uneven extraction. Fine dust over-extracts and tastes bitter; coarse chunks under-extract and taste sour. A blade-ground cup contains both at once, which is why it can taste harsh and weak simultaneously — a combination that confuses people because the usual fixes work against each other.

**Figure: Particle consistency and what it costs**

| Item | Value |
| --- | --- |
| Conical burr, quality ($120 and up) | 2 |
| Flat burr, entry level (About $60–100) | 3 |
| Conical burr, entry level (From about $40) | 4 |
| Hand grinder, decent (From about $35) | 3 |
| Blade grinder (Powder and boulders together) | 9 |

_Approximate relative spread of particle sizes from each grinder type. Lower is better — it means the grounds are more alike._

> **If a blade grinder is what you have** — Pulse it in one-second bursts rather than holding it down, and shake the grinder between pulses to move the uncut beans down. It will not match a burr grinder, but it substantially narrows the spread. Grinding slightly coarser than you think you need also helps, because the dust fraction is what does the damage.

## Grinding for each brewer, in practice

### Dialling in a new bag

1. **Start at the recommended setting** — Whatever your grinder's manual says for your method. Weigh the coffee — 60 g per litre for most methods — so you are only changing one variable.
2. **Brew and taste for the fault, not the flavour** — Ignore whether you like it for a moment. Ask whether it is bitter and drying, or sour and hollow. Those are the two directions.
3. **Move one step, not three** — Bitter, go one step coarser. Sour, one step finer. Grinder settings are logarithmic in effect — a single click changes more than it looks like it should.
4. **Re-taste before changing anything else** — Only when the sour-bitter axis is right should you adjust ratio for strength. Getting these out of order is why people chase their tail for weeks.

## Grinding without a grinder

Whole beans can be broken down by hand, and the results are usable if you accept an uneven grind.

1. Rolling pin: beans in a sealed freezer bag on a board, crushed rather than rolled. Press down and rock; do not roll, which slides them around. Gets you to a coarse-medium.
2. Pestle and mortar: the most controllable manual option. Crush, do not grind in circles, and work in small batches. Can reach medium-fine with patience.
3. Heavy pan: beans in a bag, whack with the flat base. Coarse and uneven, but fine for French press or a cold steep.
4. Blender or food processor: pulse in short bursts. Produces a very wide spread, better than nothing for immersion methods and unsuitable for espresso.

The manual options all skew coarse, which suits immersion brewing — a French press, a cold brew jar, or a [saucepan brew](https://trysix.online/how-to-make-coffee-on-the-stove). None will get you to espresso fine, and attempting it produces mostly dust.

## Where to have beans ground

Almost every independent roaster will grind a bag for you at the till, and most supermarkets with a bean section have a grinder next to it. Tell them the brewer by name — 'a Bialetti moka pot', 'a filter machine', 'a cafetière' — rather than saying fine or coarse, because those words mean different things to different people.

The trade-off is staling. Whole beans hold their character for weeks; ground coffee has vastly more surface area exposed to oxygen and noticeably flattens within about a week of grinding. If you are buying pre-ground, buy small bags often rather than one large one. [How to store coffee beans](https://trysix.online/how-to-store-coffee-beans) covers keeping either form fresh, and [where to buy coffee beans](https://trysix.online/where-to-buy-coffee-beans) covers reading a roast date.

**How fast each form loses its character, stored properly at room temperature.**

| Form | Noticeably flat after | Why |
| --- | --- | --- |
| Whole beans, sealed with a valve | 3–5 weeks from roast | Low surface area; CO₂ still escaping |
| Whole beans, opened bag | 2–3 weeks | Oxygen ingress each time you open it |
| Ground, sealed | 7–10 days | Surface area is many times higher |
| Ground, opened | 3–5 days | Both effects at once |

## Frequently asked questions

### What grind size do I need for a drip coffee maker?

Medium — roughly the texture of coarse sand. That matches the four to six minutes of contact time a drip machine gives. Too fine and the cup turns bitter and the basket may overflow; too coarse and it tastes sour and thin.

### Is a burr grinder really worth it?

It is the single most cost-effective upgrade in home coffee. A burr grinder produces particles of a consistent size, so all the coffee extracts at the same rate. A blade grinder makes powder and boulders together, which over-extract and under-extract simultaneously.

### Can I grind coffee beans in a blender?

You can, in short pulses, and it works acceptably for French press or cold brew. The particle spread is very wide, so the result is uneven — and it will not get anywhere near fine enough for espresso.

### How long does ground coffee stay fresh?

Sealed, about seven to ten days before it noticeably flattens; opened, three to five. Grinding multiplies the surface area exposed to oxygen, which is why whole beans keep several times longer than the same coffee ground.

## Sources

- [Systematically Improving Espresso: Insights from Mathematical Modeling and Experiment](https://doi.org/10.1016/j.matt.2019.12.019) — Matter (2020) (DOI 10.1016/j.matt.2019.12.019). Supports the relationship between grind size, particle distribution and extraction consistency.
- [Coffee Standards](https://sca.coffee/research/coffee-standards) — Specialty Coffee Association. Supports the grind-size-to-brew-method matching and the extraction targets behind it.
- [Effects of different coffee storage methods on coffee freshness after opening of packages](https://doi.org/10.1016/j.fpsl.2022.100893) — Food Packaging and Shelf Life (2022) (DOI 10.1016/j.fpsl.2022.100893). Supports the claim that ground coffee loses freshness substantially faster than whole beans after opening.

## Related articles

- https://trysix.online/what-is-ground-coffee
- https://trysix.online/how-to-store-coffee-beans
- https://trysix.online/how-to-make-a-perfect-cup-of-coffee
- https://trysix.online/where-to-buy-coffee-beans

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