Coffee by Numbers

in #coffee8 years ago (edited)

Making the Perfect Espresso

The coffee bean is fabulous natural resource that when treated right releases its elixir of brain fuel.

Over the years, coffee has grown substantially in popularity, even overtaking the humble tea leaf in traditional tea drinking countries such as the UK and India.

I imagine some of its growth in popularity has been down to the global expansion of Starbucks and other coffee chains.

Unfortunately, many of the large chains are not purveyors of the perfect cup of coffee. You need to seek out speciality artista coffee shops for that.

But how do you make the perfect the cup of coffee at home ?

Home Coffee Equipment

To make the perfect cup of coffee there are a few tools you will need.

I am focusing here on espresso based coffees but there are other types of coffee such as Filter coffee or pressed coffee as well as more traditional turkish coffees and Mokka pot based coffee.

For espresso based coffee you will need:

  • A decent quality Espresso coffee machine
  • A good coffee bean grinder
  • A US digital scale or UK digital scale (with at least 0.1g increments)
  • A stopwatch/timer (use your smartphone)

Here is my equipment which includes:

Image of Coffee Equipment

The Grinder

A good grinder is important as you will need a fine grind of coffee to make a good espresso.

Many cheaper grinders tend to produce coarser grounds that are not optimal for espresso coffees.

When rubbed between your fingers, the coffee grounds should feel like table salt. If it feels like sugar granules then it is too course. If it feels like flour, it is too fine.

The Espresso Machine

There are a variety of good espresso machine utilising different mechanisms for producing the water.

Boiler Machines

The main types are boiler based machines where they boil the water in a water tank. These can range from £150 ($200) to £1,000+ ($1,000+). A good boiler machine typically has a stainless steel or aluminium boiler.

A popular budget choice is the Gaggia Classic in the US and Gaggia Classic in the UK.

These are great as once heated up, they are ready to produce coffee whenever you are. On the downside, they can take 15-30 minutes to fully come up to the right temperature in the morning.

If you like milk based coffee, a boiler machine will need a bit of time between frothing the milk and pulling the next coffee.

There are dual boiler machines like the Breville Dual Boiler in the US or the Sage Dual Boiler in the UK.

The dual boiler machines have a separate boiler for frothing/steam and a separate one for the coffee which means you can pull multiple milk based coffees without delay.

Heat Exchanger Machines

There are other machines that store the cold water in a tank and then run it through a series of heated pipes that warm the water on demand - exchange heat, hence the name. The benefit of these is that they don't typically require as long to warm up but are not as adept at pulling multiple coffees as the hated pipes will start to cool and you need to wait for them to heat up to the right temperature again.

The Science of the Perfect Coffee

Assuming you now have an espresso machine and grinder, how do you make the perfect cup ?

Coffee Beans

A great coffee is ideally made from freshly ground coffee. A ground coffee bean is at its optimum for approximately 15 minutes after grinding.

Yes, you can purchase pre-ground coffee but if you are using it over a period of a week, the coffee grounds will start to 'stale' after 15 minutes. Nothing wrong with pre-ground coffee but our focus here is trying to extract the perfect, or near as perfect, coffee.

Also, for even better coffee, try and use coffee beans that have been recently roasted. Ideally, the coffee beans should have been roasted 5-20 days before use. You don't want to use beans that have just been roasted as they are still emitting gases.

In the UK, I quite like the beans roasted by Rave Coffee

image of coffee beans

So, now you have your recently roasted beans, grind them to an espresso consistency at the time you are making the coffee.

The Numbers

So, the question is how much coffee to how much water.

An espresso machine will typically come with a single filter and a double filter basket. I would recommend throwing the single filter away and only using the double filter basket. You will get much better results and more consistency from cup to cup with a double filter.

These filters are typically sized for 18g of coffee grounds.

Using the digital scales, weigh out 16-18g of ground coffee and put it in your double filter.

Image of weighed portafilter

So now you have your 18g of coffee in your filter, how much water do you run through it.

Depending on the type and strength of coffee you are looking to extract, will determine the ratio of coffee to water.

Espresso TypeRatio of Grounds in to Coffee Out
Ristrettoa ratio of 1:1 to 1:5 (18 grams in - 18.0 to 26.0 grams out)
Espresso1:1.6 to a 1:2.5 ratio (18 grams in - 28.0 to 45.0 grams out)
Lungo1:3 (18 grams in - 54.0 grams out)

Using your digital scales, place them under the portafilter on the machine, place your cup on the scales and use the 'Tare' button on the scales to zero the scales. This means you will be able to measure the grams of coffee extracted from the bean, as per the above scale.

When you hit your target weight, stop the machine.

image of weighed espresso

The other factor determining the perfect cup, is the time it takes to extract the coffee.

I tend to go for an espresso strength on a 1:2 ratio, i.e. for 18g of coffee grounds, I aim to extract 36g of espresso.
To get the right taste, i.e not too weak and not too bitter, you need to extract the 36g within 25-30 seconds.

It is unlikely you will get this perfect the first time, but a bit of experimenting and tweaking should get you to the target. The key variables that affect the time it takes to extract the coffee is the fineness/coarseness of your grounds and how tightly packed the grounds are when you tamp/press the coffee in the filter.

Adjust coarseness on your grinder and try again.

Summary

So, to sum up, the numbers we are trying to achieve for the perfect espresso are:

  • 16-18g of coffee grounds
  • produce 32g to 36g of espresso
  • within 25-30 seconds

image of espresso

Good luck !

Note: All images are taken and owned by @super-spy

Sort:  

Thank you for posting this information. Are some machines louder than others? Principle...Decisions must be based on information. Great application here.

To be honest, I don't think I have come across a quiet machine but yes, some are louder than others.

If noise is an issue, your best bet might be to get a demo in your local department store or coffee machine retailer.

Thank you for your reply. Perhaps the machines manufactured for domestic use are not as loud as the ones for commercial. The sound can fill an entire restaurant, it seems. However, the result is worth it. Cheers.

Yes, commercial machines are louder. Home machines are still noisy when the pump is active but only for the 20-30 seconds it takes to pull the espresso.

How very kind of you to reply. Thank you for futher needed details. Cheers.

Congratulations @super-spy! You have received a personal award!

2 Years on Steemit
Click on the badge to view your Board of Honor.

Do not miss the last post from @steemitboard:

Introducing SteemitBoard Ranking

Support SteemitBoard's project! Vote for its witness and get one more award!

Congratulations @super-spy! You received a personal award!

Happy Birthday! - You are on the Steem blockchain for 3 years!

You can view your badges on your Steem Board and compare to others on the Steem Ranking

Vote for @Steemitboard as a witness to get one more award and increased upvotes!