When first brewing coffee, it can be a very intimidating task. In this blog I will attempt to give beginners a general overview of brewing. I think it is important to give people an overall picture of what’s happening behind the scenes of a brew. It will make it more enjoyable and less intimidating for the next time you attempt to make a coffee.
When I started brewing, I looked to the internet for some step-by-step brew guides. As there are many different ways to brew coffee – such as espresso, v60 or French press – the step by steps are method specific. These are great to achieve a quick fix to brew. However I didn’t learn much. As the saying goes give a man a brew, caffeinate him for the day. Teach a man to brew and caffeinate him for a life time!
Now, let’s say you recently bought a beautiful V60 and you buy coffee from an amazing roaster. However you aren’t quite sure how to brew it so you go to their website. You look to their website and find this brew guide…
Now if you follow the brew guide and use their coffee you can be sure it will taste pretty good. However, one thing is missing, and it’s the same in every brew guide I’ve seen to date – they don’t explain why it tastes the way it does. What have all these steps you just followed done to make such an amazing coffee? If you wanted to use a new method of brewing, have you learned anything that you can transfer over and have a stab at it? Apart from the recommended coffee to water ratio? Not really.
So what is happening behind the scenes? To me the best way to treat brewing is like a game! Here is a general brew guide, which I feel will help newbies grasp the concept of coffee and how it brews.
This is a coffee bean (great start Darren!). Coffee beans are generally around 30% soluble. When we brew coffee we extract a percentage from the available 30%.
Coffee extraction is the process of dissolving soluble flavours from coffee grounds in water. Proper brewing of coffee requires using the quantity of coffee, ground precisely, extracted to the correct degree, controlled by the correct time and correct temperature. However not all soluble flavours are desirable!
So to extract the coffee, we must grind it first. The reason you grind coffee is because it creates more surface area which means more available area for the water to extract from. The recommended extraction is from 18% to 22% (side note: this is measured with an expensive tool called a refractometer. Have a look at the link at the bottom of the page to see how it works). This is where we treat it like a game. The goal is to stop the extraction between those two numbers. The rules to the game are as follows:
- Finer the grind the quicker the extraction (needs less interaction time with water)
- Coarser the grind the slower the extraction (needs more interaction time with water)
- The more you agitate the coffee the more it will extract (yeah that’s why we are told to stir – who knew?!)
- If it extracts over 22% it will generally taste, bitter, dry and astringent
- If it extracts below 18% it will generally taste, sour, acidic and green (plant-like)
With those rules in place, I trust you will be eventually able to identify some over or under extracted brews (I believe in you!). It does take some practising, so don’t panic if you can’t get it perfect right away! The main thing to take is how to rectify a brew that may not taste great.
- Sour – extract more. (Longer brew)
- Bitter – extract less. (Shorter brew)
So with these fundamental rules of brewing, I challenge you to try and create your own brew guide. Remember there is no right or wrong way of brewing. For home brewers it’s only your own taste buds you have to impress. So don’t be shy and give it a go.
http://www.ehow.com/how-does_5314561_refractometer-work.html
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