A Point To Grind

By Emily Oak

I am very lucky that in my work as an educator I often get the opportunity to associate with people already active in the coffee industry, as well as people who are so enthusiastic about coffee that they are setting up a mini espresso bar at home. Unfortunately for both of these groups they often overlook or misunderstand the importance of the grinder in the whole equation of making a cup of coffee.

The grinder is arguably the most fundamental piece of equipment in any coffee brewing situation. Why? Grinders allow for the freshest coffee possible in brewing, as well as controlling the extraction of flavour and soluble materials from the beans.

True freshness in coffee can only be achieved by ‘grinding on demand’ – grind what you need immediately before you use it. The grinder intricately controls the rate at which coffee and water come together to create the magic elixir in any brewing method – plunger, filter, stovetop or espresso. The milling of coffee beans between two blades allows for the breakdown of cell walls and for hot water to mix with the soluble materials in coffee. The reason that the grinder is so important in this mix is it controls the individual size of each coffee particle, and thus, how much time and surface area are exposed to the hot water. The scale of grind [commonly referred to as coarse to fine] is usually reflective of the amount of time coffee and water are meant to be in contact.

For a plunger, where coffee and water are in contact for 3-4 minutes, the grind should be coarse. For a filter or stovetop espresso, the water and coffee are in contact for 1-2 minutes, the grind is usually medium. For espresso, where the coffee and water are in contact only for 20-30 seconds, the grind is even finer, but you also need to take into consideration the other variables of dose, tamp and environment. Ground coffee is very sensitive to weather – particularly to heat and humidity and may swell, expand or shrink in as little as 10 minutes from when it is ground to when it is used. This means that a barista – either at home or in a commercial environment – needs to constantly and vigilantly observe and adjust a grinder up to 10 times a day. It also means that the barista needs to understand how all these variables interact for every coffee that is extracted.

It is not necessarily easy to learn about grinders and grinding coffee in relation to espresso, which is why I believe in many commercial environments some coffee companies choose not to educate their customers on how to use a grinder. It takes many sessions, practical demonstrations and then practice on the part of the student to really understand.

Instead, café operators are taught not to touch the grinder, and that someone will come and visit every so often to ‘fix it’ for them. The result of this in terms of espresso brewing is a less than satisfactory cup and missed potential for a business, unless a sales rep is prepared to show up 10 times a day to observe and adjust the grinder!

In the home espresso and more generally, the home coffee brewing environment, a lack of education and understanding about the importance of grind and freshness has led to the trend of people buying pre-ground coffee in large quantities and putting it in the fridge or freezer. For home espresso users this usually leads to frustration that they cannot achieve what they usually get from a good café, or that their plunger or filter coffee isn’t quite right.

I often get asked by people when buying espresso equipment for home, what kind of machine is best in any give price range. The first thing I suggest is that no matter how they brew their coffee, if they’re serious enough to invest in machinery for home, then a good grinder is also a must. Otherwise too much is left to chance, and you’ll end up resenting your equipment – or even worse – leave it sitting at the top of the cupboard!

In the case of commercial coffee supply – unless a coffee supplier is willing to invest time and effort in showing a café operator how important a grinder is and furthermore how to use, adjust and understand it, then you’re better off looking elsewhere if you want a good cup of coffee.

Emily Oak is Senior Coffee Trainer at the Sydney Coffee Academy at Ryde TAFE and an industry consultant. Since 2004 she has held the positionof Hemisphere Coordinator for the Asia Pacific region for the WBC. Visit www.freshground.com.au

Tags: , , , , , ,

Leave a comment or a question

You must be logged in to post a comment.