You can go out and purchase the best quality beans money can buy, and still end up with a horrible tasting cup of coffee. The reason you ask? If the grind size is not right for your brewing method, your whole coffee drinking experience can go out the window. Coffee gurus state that the flavour of the grounds begins to disintegrate within half an hour of grinding. Hence, the first step to great tasting coffee, after bean quality, is to grind your beans just before brewing.
While the grinding before brewing part sounds simple enough, there is a bit more to correctly grinding your beans and that is the purpose of the first part of this post; to educate you on how to go about grinding your coffee beans so you get that great taste in every cup.
Basics of Grinding
While there are more than a dozen different ways you can brew your coffee, there is only one reason for grinding the coffee beans. That is to force out all the good stuff inside the bean and put it in the cup for you to drink. Imagine placing a coffee bean in a cup of hot water, there is only so much space where water touches the bean and dissolves the goodness out of it (forget for the moment that the really good stuff is inside the bean). Also while the goodness may be removed from the surface, reaching all the way into the middle of the bean is not possible; the distance to the middle of the bean is too great for the water to penetrate in the amount of time it typically takes to brew the coffee. Hence, we break apart the bean into smaller pieces.
When we break the bean into two pieces, we increase the amount of area the water comes in contact with the coffee and if we break it down to even smaller pieces, the area increases even more. This also shortens the distance to the centre of each particle, resulting in greater quantity of oils and other flavourful soluble substances that will end up in your cup of coffee. The overall result is that the smaller the size of the grind, the greater the amount of flavours extracted, and the short the duration need for extraction.
There are only a few basic laws you have to remember when it comes to grinding coffee beans.
- Grind the beans when you are ready to brew coffee
- Ensure you are using the correct grind size, going from coarse to almost powder, depending on the way you plan to brew.
- Do not compromise on grinder quality
- Maintain a clean grinder
Types of Grinders:
Blade Grinders
Before we get to actually grinding the coffee, it is important to talk about purchasing the right grinder. There are really only two main types of grinders you need to concern yourself with. The cheapest variety makes use of a razor-sharp blade that grinds the beans as it spins at high speed. Such grinders offer a number of advantages.
- They are very cost effective
- Easy to operate, simply plug in and push the button.
- The small size is great for saving counter space.
- They only have one moving part, which makes them easy to clean
However, these types of grinders are inadequate for several reasons.
- It is difficult to judge the grind size. Since they function by pulsing, you have to keep taking a peek to see if the grind size you desire is reached, and it is easy to over shoot!
- They heat up, thus scorching the grinds
- The grind is uneven with larger and smaller particles mixed together.
Burr Grinders
Burr grinders provide a greater range of coffee grind sizes with more precise size adjustment. Also there is more consistency in each grind sizes. Types of burr grinders include flat, conical or a mixture of the two and they all employ the same basic concept. The pair of burrs is sharp with one non-mobile surface and the other a moving wheel grinding against it like a mill. The material of the burrs may be steel or ceramic and the coffee beans fall into the two opposing burrs and gets cut from both sides.
The flat burrs are cheaper but operate at higher speeds than the conical ones. The high speed heats the bean grind producing static issues. When there is static charge in the grind, it sticks to everything making cleaning a headache. Conical Burrs are currently the best possible types of grinders you can buy. They are more expensive, but then they also give a greater variety of grind sizes and they work at slower speed, which keeps the motor cool and grinds are less likely to stick or scorch.
Grind Size & Brewing Method:
The size of the coffee grinds and the amount of time the grinds are exposed to the water determine the flavour of your coffee. If the size of your grinds is too coarse for your brewing method, water will not be exposed to the grinds for sufficient length of time and your coffee will be weak. Conversely if your coffee grinds are too fine for the selected brewing method, water will be exposed to a larger surface area for a long time and the coffee will turn out bitter. So the general idea is that the longer the water is going to be exposed to the grinds, the coarser they should be to get a great tasting brew.
Another important factor to consider is the consistency of the grind. If your coffee grinds are a mixture of fine and coarse sized grinds, then you are not going to get the best possible cup regardless of the method you select. The flavours from the tinier particles will be extracted faster than the larger particles with the net result of a poor extraction.
So now that you have learned everything there is to know about grind sizes, grinding and their impact on flavour, here are some basic parameters to go by:
French press and percolators require coarse sized particles where chunks of coffee beans are easily distinguishable. Looking somewhat like kosher salt, it can be achieved by setting he burr griner on the coarsest position.
The standard drip brew machine using flat bottomed filters, turn out a good cup of Joe if grind size that is less coarse compared to the one used in French press but coarser than grains of table salt. Machines using cone filters need a finer grind size.
Chemex and Aeropress work best with coffee grinds resembling the coarseness of table salt.
Espresso machines or Turkish coffee require the use of extra fine sized particles looking somewhat like powdered sugar.
