One of the first things people realise when learning to make coffee is the number of variables which affect the coffee quality. This post will explain what, for many people is the most important variable, master this and you will be creating better coffee than most cafes.

Some of the variables which affect your coffee are:

• The quality of the beans
• The roast and blend
• The machinery (maintained machine, and grinder)
• The temperature of the machines heads at the time of extraction
• The coarseness of the grind
• The extraction cut off point

I will stop there, but you can see there is half a dozen before mentioning any regarding the barista technique, or the milk, the list is almost never ending.

The coarseness of the grind should be the only factor which affects how fast or slow the coffee extracts through the handle (tamp pressure is always the same). Ground coffee contains a wide range of flavours, from the sweet, aromatic to the hideously bitter.

Adjusting the grind even minutely will affect the extraction rate and have a great impact on what flavours you are able to enjoy or have to endure.

It is the controlling of the extraction rate (i.e the grind coarseness) which depicts what flavours will end up in the cup.

• If it extracts too fast (grind too coarse), there is not enough time for the hot, pressurised water to extract the sweet, desirable flavours, leaving you with a weak, poor tasting coffee.
• If it extracts too slow (grind too fine) the hot, pressurised water takes so long to get through the grinds that it ends up burning the coffee on the way through leaving the drinker with a bitter taste in their mouth that will last for up to an hour.

The exact correct extraction rate will differ slightly from blend to blend, however it should never be gushing out of the spouts, nor should it be just drip, drip, dripping throughout the entire extraction (a bit at the start is fine). The ideal extraction can be described as a 'rats tail', as from one spout, the extraction comes back in towards the centre of the handle, giving the appearance of the curve in a rats tail. The correct extraction with freshly roasted beans will leave you enjoying a naturally sweet, rusty brown coloured coffee that you would happily pay twice as much for!

So go ahead, play with the adjustment on your grinder between the fine and course settings. Depending on the grinder, a small adjustment will affect the extraction flow considerably.

Hopefully with a few  importance of getting the grind right and your grinder won't be one of the ones I see regularly with a sign stating 'do NOT adjust the grind', because it should be compulsory! Enjoy...

Adrian

What are your thoughts on the correct extraction rate? Let us know in the comments below.

Hello and welcome to Espresso Coffee School's first blog post. Through this blog we will keep you up to date with the latest coffee trends, give you the low down on different techniques used by the coffee industry and generally help in any way we can to improve the standard of espresso coffee being served!

Contributions to the blog will come from Espresso Coffee School tutors and associates, and will include reviews on machines, beans and cafes/espresso bars plus anything else that we feel will help you get the most out our knowledge and passion for great coffee.

So bookmark this blog, email to a friend/colleague or add our RSS feed, and let’s get the fresh coffee grinding. And of course, we’d love getting your feedback on Espresso Coffee School and this blog — and what you want to see discussed (and showcased) in the future.

Until the next post,
Adrian