How to Grind Coffee

Before you start: beans, scales and a suitable setting

Have your brewer ready before grinding. Grinding accelerates the release of carbon dioxide and aroma compounds, while exposure to oxygen contributes to staling. There is no useful universal countdown after which grounds suddenly become unusable, but grinding immediately before brewing avoids unnecessary storage.

Use scales rather than a scoop to measure your dose, meaning the mass of coffee for the brew. Weighing makes it possible to repeat a recipe without relying on how tightly beans or grounds fill a spoon.

A burr grinder breaks beans between toothed grinding surfaces. Adjusting their separation changes the grind, giving more control than a blade grinder, which chops beans into progressively smaller pieces as it runs. Neither produces particles that are all exactly the same size.

Choose a starting setting from your grinder’s instructions for the intended brewer. Setting numbers and clicks are model-specific: they are not a shared measurement system. Use the grind size chart for broad orientation, rather than copying a number from an unrelated grinder.

This article concentrates on operating the grinder. The wider relationship between the particles you produce and the drink you brew belongs in grind size and extraction.

How to grind coffee: a repeatable method

The following practice routine uses Hario UK’s filter recipe as a reference. Its brewing figures are starting points for that brewer, not universal grinding rules.

1. Prepare the brewer. Fit and rinse the paper filter, then discard the rinse water. Have enough water ready for the rinse and the brew so that the grounds do not sit waiting afterwards.
2. Weigh the beans. Measure 15 g into a clean, dry container. For this example, use 250 g of brewing water, approximately 250 ml when measured cold. That is a coffee-to-water ratio by weight of approximately 1:16.7.
3. Set the grinder. Start at the manufacturer’s medium-fine filter recommendation. Follow its adjustment procedure, including any instruction to run the motor while moving finer.
4. Grind the dose. Load within the grinder’s capacity. Turn a manual grinder steadily in its specified direction, or operate an electric grinder according to its instructions. Stop when grinding is complete, rather than applying a universal number of seconds.
5. Check the grounds. Weigh the output in a tared container. Record any difference from the input before transferring the grounds to the brewer.
6. Make the reference brew. Use water at 92 to 96 degrees Celsius. Wet the grounds thoroughly, wait around 30 seconds, then continue pouring to 250 g total water. Hario’s guide suggests an overall process of around 2 minutes 30 seconds.
7. Taste and record. Note the setting, ground dose, brew time and flavour. On the next attempt, make a small grind adjustment while keeping the other parts of the routine unchanged.

Do not discard a pleasant brew because it misses the reference time. The purpose of this exercise is to give your grind adjustment a consistent test, not to turn the timer into a pass-or-fail judge.

Manual Coffee Grinding

Set the grind before loading beans unless your manual specifies otherwise. Where adjustment involves finding a zero point, follow the maker’s procedure gently: do not tighten the dial hard against its stop. Some grinders use external numbered collars, while others require counting clicks from a reference position.

Secure the grounds container and fit the handle correctly. Hold the body firmly in a comfortable position and rotate in the specified direction. For example, 1Zpresso’s E-Series instructions specify clockwise grinding, but check your own model rather than assuming that every mechanism is identical.

For a repeatable technique, keep the grinder’s position and your turning action reasonably consistent. There is no need to race. Continue until the beans have passed through and the normal grinding resistance disappears, then stop rather than spinning the empty mechanism unnecessarily.

If the handle locks, do not wrench it through the obstruction. Stop, empty what you can safely remove, and follow the maker’s jam-clearing instructions. Never put fingers or tools into the burrs while turning the handle.

There is no single correct grinding time for a hand grinder. Use completion of the dose as the endpoint, and keep any timings you record specific to your grinder, setting and coffee. If a batch exceeds the hopper’s stated capacity, split it rather than packing the beans down.

Electric Coffee Grinding

Put the grinder on a stable, dry surface and seat the grounds bin or receiving container correctly. Keep the lid and other guards fitted during operation.

With single dosing, you weigh one brew’s beans before loading them. With a hopper-fed routine, beans remain in the hopper and you dispense a dose from that supply. In either case, check the mass of grounds you will actually brew rather than assuming the grinder has delivered the intended amount.

Follow the model’s adjustment instructions closely. Baratza advises running its grinders during significant moves towards a finer setting because beans trapped between the burrs can otherwise be compressed. That is manufacturer-specific guidance, not permission to disregard another grinder’s manual.

After a substantial setting change, retained grounds may still reflect the previous setting. Where the manufacturer recommends it, grind a small separate quantity to clear those transitional grounds before assessing the next brew.

If your electric grinder uses blades, operating time controls how far the beans are chopped rather than selecting a burr gap. It offers less control over particle uniformity. Keep the batch and operating routine consistent, follow the manual, and do not expect a setting chart for burr grinders to translate directly.

For a fuller explanation of particle variation, see the grind consistency guide.

Static, retention and the Ross Droplet Technique

Separate static from retained coffee

Static is electrical charge generated as coffee particles fracture and rub during grinding. It can make grounds cling to surfaces or scatter around the receiving container.

Retention means coffee left inside the grinder, including its chamber and exit chute. Static can contribute, but coffee can also remain in internal spaces or accumulate around a restricted outlet.

Weighing input and output is a useful everyday check, not a complete retention test. Equal masses do not prove that all the grounds are new: some coffee from the previous dose can leave while some of the current dose stays behind. Treat the result as a dosing check rather than a laboratory measurement.

Use only the grinder’s intended clearing features, such as its supplied knocker or bellows, following the instructions. Do not hit the body or insert anything into an operating grinder.

Use RDT only if the manufacturer permits it

The Ross Droplet Technique, usually shortened to RDT, involves adding a very small quantity of water to whole beans before grinding to reduce static.

Controlled laboratory experiments published in Matter in 2024 found that added water reduced electrical charging and particle clumping. The researchers also observed changes in espresso flow and extraction under their experimental conditions. Those results do not establish that every grinder needs water or that every drink will taste better.

Check your grinder manufacturer’s advice first. RDT may be unsuitable for some grinders, and research on static reduction does not establish long-term compatibility with every burr, bearing or electrical assembly.

If the manufacturer permits it, use only the very small amount it recommends. Apply it to the weighed beans in a separate container and distribute it before loading. Do not pour or spray water into the grinder, soak the beans, or dampen coffee that will remain stored in a hopper.

There is no universal safe spray count: atomisers dispense different amounts. If the manufacturer gives no clear approval or method, skip RDT and use its recommended dry routine.

Cleaning the grinder

Coffee oils and small particles can accumulate in the grinding chamber and chute, affecting flow and increasing the risk of blockages. Cleaning is therefore part of a repeatable grinding routine, not merely tidying the worktop.

After use, remove loose grounds from accessible areas with a suitable dry brush. For deeper cleaning, follow the model’s disassembly instructions and keep track of the order and orientation of parts.

For an electric grinder, switch off and unplug before removing components or reaching inside. Do not assume every removable part is washable: some manufacturers allow washing detached plastic hoppers and bins, while others specify dry cleaning for the grinder. Any permitted washed parts must dry thoroughly before refitting.

Use cleaning products only where the manufacturer approves them. Do not substitute rice: Baratza warns that rice fragments can strain or jam its grinders and leave residue.

Follow the maker’s cleaning schedule, then check assembly and the grind setting before brewing again. A useful maintenance note records what you removed and the setting that worked before cleaning.

Troubleshooting your grinding routine

These checks address handling and operation. For the wider brewing consequences, read about the impact on brewing.