How to Get the Best Coffee from Your Grinder

  • Posted By: Craig Campbell
  • |
  • Category: Beans

How and when to adjust your coffee grinder - did you know a simple grind or dose adjustment can make a world of difference to your coffee experience?

How well do you know your coffee grinder?

This is a rather long article, but I encourage you to read it as there may be something of value that helps improve your coffee experience.

Often overlooked as noisy, messy, and rather ugly appliance consuming critical bench space in a kitchen.

During the research and buying stage of sourcing coffee equipment, the grinder is mostly always relegated as a secondary consideration behind the importance of investing in an expensive,  shiny espresso machine. However, the humble grinder does in fact play a more critical role in the overall brewing process and deserves equal attention and care.

There is one bet I will always punt on - that coffee enthusiasts eventually come to appreciate the grinder is EVERYTHING. It takes a while for this realization to sink in and typically it's only after a few upgrades or extensive research involving sometimes exaggerated stories of stratospheric improvements read on an internet blog. Whilst it's tempting to be sceptical of such claims, the reality is that your coffee experiences and overall enjoyment will elevate to another level once you understand the dynamics of your grinder and manage it accordingly, or acquire a decent grinder that does the job of producing quality espresso grounds.

A wise saying has been circulated across the internet for more than a decade - you can match a quality grinder with an average machine, but you can't match an average grinder with a quality machine. In other words, invest more in a grinder than you had originally estimated. Many of the customers I speak to on a daily basis persist with sub-standard grinders, or are not patently aware of the impact of the grinder upon their beverage.

For espresso style brewing (or extraction) the grinder is perhaps the most critical element affecting the result in the cup - of course, technique has a large role to play in that statement.

Dialling in a grinder

The primary challenge with espresso preparation is dialling-in the grinder - getting that perfect grind and dose setting to enable your machine to produce the best possible beverage. Espresso extraction is a razor-thin dynamic that is less forgiving than other brew methods such as filter, drip or plunger.

Dialling in a grinder is not a simple or easy feat and at times can trip up even the most experienced coffee enthusiast. The most frustrating part is that what you have dialled in today may be slightly different tomorrow or in a few days time. Coffee changes as it ages, especially fresh roasted coffee within the first 14 days and the beans in your grinder hopper will absorb moisture and off-gas - constantly changing especially in fluctuating ambient temps.

Overwhelmingly, the #1 challenge we see affecting our customers are the skills required for knowing how and when to adjust the grinder and dosing.

Generally, we receive comments like "I never touch the grinder settings", or "we don't purge the grinder if it's been sitting for a few hour or day(s) unused", or "we just pre-grind the fresh beans weekly to avoid making so much noise early in the morning".

All grinders have different characteristics - whether it's the amount of adjustment (stepped or micro-stepless), on-demand or doser (into a chamber) and the level of ground coffee retention.

Retained Grounds

Generally speaking, the larger the grinder, the greater the amount of ground coffee retention (there are a couple of models that have less, but these are predominantly cafe commercial and expensive).  Retained grinds are a bad's that simple and we can't sugar coat the facts folks.

Many of our customers are unaware that ground coffee loses the majority of it's vibrant volatiles within 15 minutes of being ground (the aromas, body, essential compounds for producing crema).

If you have ground coffee backed up (retained) in your grinder (you can't see it, but it's really there) after many hours of sitting idle, or say the next day, that ground coffee you dispense into your group handle on the next beverage will be lifeless - a reason why the first cup of the day might be a "sink shot". Have you noticed the colour of the first shot is pale and lacking crema or it gushes ???? then it's time to purge those retained grounds.

Purging the grinder involves running a bit of coffee through so that stale retained grounds are "pushed or flushed out". You can't use these stale retained grounds for espresso so you can either put it aside for plunger or use it in a coffee scrub. For some people, this is a horrific revelation - such a waste !. The amount to purge varies from grinder to grinder and what tolerances you are happy with accepting. At the very minimum, you should be purging approx. 1x full/double shot of stale retained grounds from the grinder before the 1st cup of the day. For the large conical grinders used in cafes, this can be 1.5 or up to 2x, however few households have these types of grinders in their kitchens.

An alternative to purging involves a measure/weigh of just enough for the dose plus a small margin so that the chambers and pathways remain relatively clear, however, this is effectively purging but less wastage and comes at a cost of being time-consuming and requiring additional tools such as blowers, brushes, vacuums, etc. to force trap areas clean, or modified bean hoppers that allow access. There will be some loss/wastage as ground coffee is partially statically charged and manages to stick or cling to most surfaces.

Adjusting the Grind

Many of our customers enjoy the range of single origin coffees. Whilst this journey of discovery is a fascinating experience, the flip side of this adventure requires a more careful approach setting the correct fine/coarse to properly extract the desired coffee attributes.

Single origin coffees amplify the need to dial in the grinder and dose. In other words, changing from a Sumatran or Monsoon Malabar to a hard/dense bean from Central America or Ethiopia may require changing your grinder from a fine grind to a coarser grind and also changing the dose.

You may also notice a difference if you have switched from a single origin to a blend, or from an old pack to a fresh pack.........I know what you are thinking - this is insane !!! just so many variables.

Unfortunately, it's dangerous for us to prescribe the grind settings for a specific coffee due to a number of reasons:-

the vast range of different equipment, settings and techniques used by people.
the age or wear of equipment.
a prescribed grind setting may affect your approach to preparing the coffee, e.g. the label says fine grind, so you waste too much coffee attempting to achieve a fine grind for no discernable difference in cup's a time and place thing you have to be there, not read it from a label.

Adjusting for fine/coarse is not as simple as turning the collar on the throat of the grinder. Most people fall into the trap of making an adjustment and expecting that change to be instantly noticeable on the next dose. Retained grinds often mean that the full effect of the adjustment you made to the fine/coarse could take 2 or 3 shots to fully effect.

I've seen people getting frustrated at trying to dial in a grinder by making adjustment after adjustment without allowing the change to work through in terms of ground coffee........the result is they either choke the espresso machine or produce a "gusher" - a pendulum swinging from one extreme to the other.

Constant changes of the grind setting can mean you are chasing your tail round in circles as there is a propensity to also affect the dose. For example, the finer you make the grind, the smaller the dose will appear (physically), hence you may visually consider that there is insufficient ground coffee in the portafilter and dose to your preferred level. Likewise, the coarser the grind, the less coffee volume that will be dispensed.

It's possible at times to use dose in lieu of a fine/coarse grind setting change. In other words, if you find the pour was too fast, you can increase the dose without touching the grind setting. Similarly, you can also dose less if you encounter an over-extracted espresso pour (choke, dripping, etc).

My advice is to always adjust dose before grind setting as it's easier and faster to reconcile the dose change to the pour whereas a grind adjustment takes a few shots. I use this method every day when switching from bean to bean during testing......because I can't always wait for a grind setting change to effect in the coffee - dose change is quicker.

There are times when a dose change cannot compensate adequately, such as when you pack the portafilter too high and need to tamp with excessive pressure - this can cause channelling as the compacted ground coffee fractures if it has not been distributed evenly. When dosing low, you can experience an increased agitation at the top of the puck from excess water that can loosen and disturb the tamped coffee that can also lead to channelling.

It's important to ensure you only ever change one thing at a time......then observe and understand the impact carefully. If you change the grind setting and also inadvertently change the dose, you will be either adding to or subtracting from the expected outcome, leading to confusion. Best thing is to write down on a piece of paper what you did each time......


The age of a coffee (since roasting), how it is stored (type of container), levels of exposure to oxygen and the ambient temperatures can all affect the performance or behaviour of coffee as it runs through a grinder and the espresso machine.

In warmer temperatures, the coffee may expand and may lead to "choking" on the espresso machine. As the coffee ages, you may find that a slightly finer grind is required to keep the espresso pour optimal. Very fresh coffee can be tricky to extract by espresso and it may require up to 10 days for the coffee to stabilize.

Developing an acute awareness of your grinder's range of operation and nuances will lead to more consistent and "tastier" coffee - something we all desire.

Cheap Grinders

For those of you that think a $50 spice grinder is suitable for preparing coffee beverages - please don't use these types of grinder for coffee. They don't grind the particles consistently meaning you end up with lots of small fines and large coarse grounds in the same pile. The resultant coffee, regardless of the brew method used will be both over and over extracted leading to combinations of bitter and sour notes in the coffee.

Even many of the cheap dedicated domestic grinders that sell for $100 - $200 at the white goods appliance stores have limited suitability for espresso coffee duty. These grinders often don't grind fine enough or they suffer from similar problems to the spice grinders.

We don't sell equipment, so we can call it as it grinders = sub-standard coffee beverages.

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