Tag: grinding

Five steps to better coffee: Step Two: The Grind

So, with step one complete, you’ll have the best beans for the job. The next step in any preparation of coffee is turning the beans into coffee ready for your machine, pot, or plunger.

The fundamental principle of coffee preparation is reproducability. The one commandment of coffee making is though shalt control your variables. We’ll move on to aiming to consistently reproduce the same routine in the next step – but getting the grind is fundamental.

Grinding immediately before use will dramatically enhance your coffee. But not all grinders are created equal. There are two “families” of grinder – burr and blade. Blade grinders aren’t ideal. They’re slightly better than nothing. But unless you do exactly the same thing every time with the same number of beans at the same weight being bashed by the blade the same number of times, you’re not going to get consistency. You’ll never get uniform sized particles and you’ll probably overheat the coffee particles due to friction. If you grind too fine you’ll overwhelm yourself with coffee that has too much oil and is too bitter.

They are a good stepping stone to improving your coffee at home – and if you want to start off with a blade grinder here are some tips:

  • Don’t hold the button down for ages and batter the coffee into dust.
  • Pulse the button for short bursts (two to five seconds) to avoid overheating the ground coffee.
  • For a fine grind go for about 20 seconds of these bursts, for a coarse grind aim for around 10 seconds.
  • These work better for plunger and filter coffee than for espresso.

Burr grinders are more expensive. But with reason. They are more mechanically complex and they produce a better result. The burrs lock together like cogs crushing the coffee into evenly sized particles. You can control the size of the particles by moving the burrs closer or further apart. You need a different sized particle for every machine and for every different brewing method (extra-fine for Turkish, fine for espresso, medium for drip filter and large for plunger).

Tips for choosing a burr grinder

  • Be prepared to spend more on the grinder than the machine (unless you’re buying a $1000 plus machine).
  • Look for maximum adjustability in the grind size, “stepless” is better than “stepped”…
  • Be prepared to waste some coffee finding the right settings.
  • Clean the grinder regularly to avoid build ups of stale coffee.
  • Steer clear of dosered grinders for home use (grinders like they have at cafes with big chambers on the front).

A good guide to burr grinders available in Australia can be found here.

July 15, 2010

The daily grind


From a Crema magazine article on espresso preparation…

Heavy conical upper burrs pull the beans down, compressing them until they shatter into smaller fragments to enter the flat burrs, to be sheared into the final grind.

Seventeen grams of the fluff exits the edges of the flat burrs and drops into a chute along the sides of the grinding head. A whirling brass paddle smashes into the coffee, whisking it on a furious circular journey at about 450 rpm until it is forced out a square portal to tumble into the dosing hopper. After grinding, this is the first real assault on our sweet coffee – the impeller smashing it into lumps, bruising the lipids and destroying a little of the fragrance.

Because of the short, pressurized percolation cycle of around 25 seconds, the final consistency of the ground coffee is critical to achieve crema, and preserve the full amount of fragrance the bean has to offer. The flat burrs shear the bean into a complex consistency that looks like snowflakes under a microscope. To accomplish this the flat burrs must remain very sharp and require changing every 500 pounds. The goal of the grind is to achieve the highest surface area of exposed aromatic oils, lipids and sugars to be transported quickly by the brewing water into your cup. The rapid percolation cycle and pressure are the unique characteristics of the espresso method that allow us to preserve the most delicate fragrance through the brewing process.

March 19, 2009

Bean thinking

I was wondering how much someone who spends as much time as I do reading about coffee could learn from a three and a half hour coffee school. The answer – not much, and a lot. 

We took the three hour course at Coffee Dominion. It’s $75 and basically includes all you can drink coffee and three hours of hands on training.

The thing about coffee is that there’s an incredible amount of diversity in thinking and practice that it’s hard to nail down any one particular theory. 

For example – many people argue that tamping (the compacting of coffee in the filter basket) is not only essential – but must be done with 10kg of pressure. Other people argue that as long as the distribution and dosing of the coffee in the basket is even, tamping is irrelevant.

What really matters when it comes to making a coffee is consistency of method. That was hammered home tonight. As long as your dosing is consistent – that is the same amount of coffee in the basket, prepared the same way, and your tamping is consistent – the only variable is the grind. The grind will vary based on humidity and variables like type of bean, depth of roast and time since roasting. If your method is the same this is the only change you’ll need to make.

I disagreed with a little bit at the start, we had a sit down session where we were told that single origin coffee is no good for espresso. I like single origin espresso. That is one type of bean from one place. The argument is that espresso requires a dark roast, that diminishes the flavour profile from the bean – so to keep espresso interesting you need to mix a broader variety of flavours. I disagreed. I don’t mind espresso made from a light roasted bean. But that’s less than relevant in the broader scheme of things. 

The “cupping” was interesting. Cupping is the primary method bean buyers use when determining what beans to order. It’s basically hot water poured over ground coffee. It’s that simple. No plunge, no brewing, no steeping. It’s just coffee and hot water. The coffee forms a crust. You break the crust that it forms and sip the coffee. Then you figure out the flavour profile – it’s similar to wine tasting really. 

Milk frothing was interesting too – I struggle to get the texture right. The goal is to make “silk from milk” and to avoid big bubbles. 

We also got to look around Coffee Dominion – where all the behind the scenes magic happens. Including a little excursion into the roasting room. I’ll put pictures up shortly.

It was a good learning experience – and worth doing. We’ve even got certificates to show for it.

February 26, 2009