Wednesday, 28 January 2009

Espresso standardisation, or reducing the witchcraft factor

In an effort to help you enjoy your Londinium coffee in the way we envisaged we now use Volvic water for all our taste tests.

This isn't a plug for Volvic or that Volvic is better than any other water, it is simply a water with key attributes that are all 'in range' for espresso use (and there aren't many bottled waters that are) and Volvic is readily available as a result of an extensive distribution network.

We hope this standardisation removes one more variable from your espresso equation.

As a reminder; 8g of coffee per shot, grind fine, tamp light, and target an extraction time of around 22s.  We could also add water temp measured at the group head of 92C.

Tuesday, 27 January 2009

If you think espresso beans should be jet black....

....then you probably won't like Londinium Espresso

We believe that coffee should be all about the 'terrior', similar to wine.

The concept of terroir developed through centuries of French wine making based on observation of what made wines from different regions, vineyards, or even different sections of the same vineyard so different from each other. The French began to crystallise the concept of terroir as a way of describing the unique aspects of a place that influences and shapes the wine made from it.

Long before the French, the wine making regions of the ancient world already developed a concept of different regions having the potential to create very different and distinct wines, even from the same grapes. The Ancient Greeks would stamp amphorae with the seal of the region they came from and soon different regions established reputations based on the quality of their wines.

If you only roast coffee just enough to caramelise the sucrose in the bean, which off sets the natural acidity in the bean, it is possible to preserve the natural characteristics of the bean that reflect the terroir of the coffee and produce a excellent, albeit unique, espresso

As far as we can tell the practice of roasting the beans very dark is associated with using inferior beans whose unique characteristics are not particularly desirable and therefore you seek to minimise their presence in the cup by roasting the daylights out of the bean. The only exception is decaffeinated coffee where the green beans have already been turned a very dark brown colour by the decaffeination process, and end up being very dark after roasting.

While it is true that many coffees are not particularly suitable for use as single origin espresso, many others are. With single origin espresso there is nowhere for the roaster to hide. The margin for error is much smaller, as it can not be masked by subsequent blending. The demand on the roaster for accuracy and precision is much greater. As is the need for good, clean, green coffee, with low defect rates and well graded to ensure all the beans are of a similar size. Otherwise the small beans end up burnt and the large beans end up under cooked and a poor cup of coffee results (a classic case of two wrongs not making a right)

Sunday, 25 January 2009

How to make Turkish coffee

The Turkish coffee maker, called "cezve", "jezve", "briki", "mbiki", "toorka" or "ibrik", has a wide bottom, a narrow neck, and a long handle. The traditional copper or brass design is preferred. It works best to use a pot to its full capacity, so you may want to own several sizes.

How to make Turkish Coffee
Ingredients:Start by adding to the ibrik 1 tsp of powder-grind coffee and 1 tsp of sugar (traditional but optional) to every 2 oz of water (assuming you will be using 2 oz servings). Add an extra oz of water to the mixture. The combined ingredients should fit just below the neck of the pot.

Brewing: Traditionally, and for the best taste, expect the brewing process to take 10-15 minutes. Slowly bring the mixture to a frothing boil on the stovetop. As the froth gets close to the top, just before it boils over, remove the Cezve from the fire, allow the froth to go down. Serve the froth in equal portions into each cup, then serve.

Serving:Fill each cup a bit at a time repeatedly, so that all cups have an even amount. Advise your guests to allow about a minute for the coffee grounds to settle to the bottom of the cup before gently sipping. Don't drinking the grounds. The result can be a magnificent beverage.

i also remember reading a different variant whereby the water is boiled off, then topped up & boiled off again, then topped up a third time and poured once up to temperature. Comments welcome on the most 'authentic' method

Thursday, 1 January 2009

The best water for your espresso machine

We have been researching the impact of different bottled waters on (i) the taste of coffee, and (ii) its impact on espresso machines.

We discovered that like many things in life it is a trade-off between the two objectives, i.e. the kind of water you need for great coffee is at odds with the kind you need to ensure no limescale forms in your espresso machine.

Using a water with the lowest 'dry residue' value (expressed in mg/L) you can find will indeed ensure you never see scale in your machine, but unfortunately it will also make your coffee taste overly 'bright' and 'harsh'.

It is complicated by the fact that the bottled waters on the market tend to fall into one of two extremes; mineral waters with very high TDS values, and typically very hard, and the 'arctic' waters with very low TDS values, very low alkalinity and typically a pH of less than 7 (i.e. acidic).

The key parameters and their target values are:

pH = 7.0

Total dissolved solids(TDS), often stated as 'dry residue@180C' = 120-130 mg/L

Hardness = 70-80 mg/L

Alkalinity = 50mg/L

You will soon find yourself saying; "great, most helpful, but I can not find all of these values on the side of the bottle".

This will always be the case for the 'Hardness' and 'Alkalinity' values as they need to be derived and we will show you how to do that below, can frequently be the case for 'pH', and is sometimes the case for the 'dry residue' value. If necessary visit the manufacturer's website, or drop them an email asking for the data.

The next step is to understand why these values are important to coffee preparation

A value from 1 (strong acid) to 14 (strong alkali), with a value of 7 being 'neutral'. It is not a linear scale, but a logarithmic one, like the Richter scale for seismic activity, so even small movements away from the neutral value of 7 quickly become quite acidic or alkali.

Alkaline water can result in dull, chalky, flat coffee. Acidic water creates bright, imbalanced coffee. You want to use water that is 'neutral' for the preparation of coffee.

As the name implies it measures the solids dissolved in the water. If too many solids are already dissolved in the water it becomes a weaker solvent and will not extract enough solubles from your coffee. Coffee made with water that has a very high TDS value will taste dull and cloudy. Conversely, water with a very low TDS value produces coffee with edgy, unrefined flavours and exaggerated brightness as the water is a very strong solvent.

The formation of limescale in your espresso machine is primarily due to the presence of calcium and magnesium ions in the water, measured as 'hardness'. For this reason it is possible to have a high TDS value, combined with a low 'hardness' value, and limescale will not readily form in your espresso machine.

Hard water does not result in a poor cup of coffee, but it will scale your boiler quickly. Water with a hardness above 90mg/L will always be reduced to a hardness of about 90mg/L as any hardness above this value precipitates out upon boiling and deposits on the inside of your boiler.

Alkalinity measures a solution's ability to buffer an acid, or its ability to resist becoming more acidic.

It is important to understand that it is quite different to 'alkaline' which is a solution with a pH between 7.01 and 14.

Water with high alkalinity neutralises coffee acids, resulting in less acidic coffee. If alkalinity is too low the coffee will be overly bright and acidic.

How to calculate the alkalinity and hardness values
Bottled waters typically disclose their minerals as mg/L or ppm, rather than mg/L CaCO3 equivalents.

To calculate the alkalinity, multiply the bicarbonate mg/L value stated on the bottle by 0.82.

To calculate the hardness, multiply the calcium mg/L value stated on the bottle by 2.5, and the magnesium mg/L value stated on the bottle by 4.2, then add the two resultants together.

Note: boiler corrosion
Acidic water with low alkalinity can potentially cause corrosion in the boiler of your espresso machine.

Worked example:
Brand: Volvic
pH: 7.0
Dry residue @ 180C: 130mg/L
Chlorides: 13.5mg/L
Calcium: 11.5mg/L
Nitrates: 6.3mg/L
Magnesium: 8.0mg/L
Sulphates: 8.1mg/L
Sodium: 11.6mg/L
Bicarbonates: 71.0mg/L
Potassium: 6.2mg/L
Silica: 31.7mg/L

So, pH = 7, good
TDS/dry residue = 130, good
Hardness = (Calcium x 2.5) + (Magnesium x 4.2) = (11.5 x 2.5) + (8.0 x 4.2) = 28.75 + 33.60 = 62.35, about right
Alkalinity = (Bicarbonate x 0.82) = (71.0 x 0.82) = 58.22, about right

Finding a bottled water that is suitable is surprisingly difficult, as detailed in the table below;

PLEASE click on the above table to enlarge it, so that it becomes legible

I trust this blog has assisted you in your pursuit for espresso nirvana and the protection of your espresso machine.

If you have any questions please get in touch & we will do our best to find the answer for you.

Biscuits 'key' to clinching business deals


Can this really help firms do business?

About four out of five UK businesses believe the type of biscuit they serve to potential clients could clinch the deal or make it crumble, a survey says.
The outcome of a meeting could be influenced by the range and quality of biscuits, according to 1,000 business professionals quizzed by Holiday Inn.
The chocolate digestive was deemed to make the best impression followed by shortbread and Hob Nobs.
Lawyers were most impressed by good boardroom biccies, the survey added.

Dunking Do-Nots
Jammie Dodgers and Bourbons were also among the biscuit types thought to help sweet-talk customers.
However crumbly biscuits are a big no-no in the meeting environment, the questionnaire found, with 30% frowning on a regular digestive in the work environment.
And when it comes to helping yourself to biscuits from a communal plate, the most acceptable number to take is two, the research concluded.
However more than half of respondents looked down on dunking biscuits in tea or coffee during a meeting.
A survey released last year, which quizzed 7,000 people, suggested that the custard cream is the nation's favourite biscuit.

We would love to see the results of a survey that compared the outcomes of business meetings that served instant coffee versus freshly brewed gourmet coffee or gourmet espresso based drinks. We expect the results would be just as dramatic. Make your first impression a profitable one with Londinium Espresso in 2009.