Your cart is currently empty!
Over the Easter week we will stick to the regular roasting schedule. Due to the Easter Monday public holiday, the shipping will be delayed of one day.
Therefore all the orders placed from the 19th to the 25th of March will be roasted on the 26th and shipped on the 29th.
Today we added a new Kenyan microlot to our range: the Gatuya AA, from the Muranga region. This coffee is taking the place of our beloved Chania Estate AA, which run out of stock.
A very sweet one, with lemon, blackcurrant and (very evident) grapefruit notes, it turns out excellent in any extraction, including filter and espresso.
A few notes from the product page:
This superb quality coffee comes from the popular Gatuya Factory wetmill in the Muranga region of Central Kenya in perfectly sealed 15kg vacuum packed bags. It is composed almost exclusively (99%) by the superior SL28 cultivar grown at about 1700masl. In the Muranga region there are mainly smallholder farms, each with 200 trees in average. They are organized in Cooperative Societies that acts as umbrella organizations for the Factories (wetmills), where the smallholders deliver their coffee cherries for processing. Gatuya is infact member of New Murarandia Farmers Co-operative Society.
The farmers are surrounded by several wetmills in the area and they are free to choose where they want to deliver their cherries as members. Due to the traditional auction system in Kenya, quality is rewarded with higher prices. The better factories will then attract more farmers by producing coffee getting the highest prices, as well as giving high payback rate to the farmers. In the cup we taste lemon and blackcurrant with a hint of grapefruit. A sweet coffee with intense, complex, and flavour profile.
This coffee is available on our web store and delivered freshly roasted to your address of choice.
Last, but not least, among the African specialty coffees we have been presenting you during this year, there is a new addition: the Rwanda Kamiro from Motherland Farmers’ washing station.
The washing station and the connected growers are located in an area characterized by ideal conditions for growing coffee at an altitude of 1700-2000 masl. There are about 1,000 farmers in the community that Motherland Farmers is supporting by providing organic fertilizers and education to foster a sustainable development and make the coffee production more profitable.
The coffee roasted by Nero Scuro offers cup notes of apricot, date, chestnut honey, floral and spices. Light roasted, it has a soft body and medium acidity.
Available now on our website, freshly roasted to order
The first we want to introduce is the El Eden lot from Finca Filadelfia, Huehuetenango, Guatemala. This coffee is the second one from our friends of Coffee Bird this year, after the tremendous success of the prestigious El Bosques de San Francisco Lot, from finca Filadelfia, Antigua.
La Reforma was established in 1904 by Manuel Perez in the prestigious Huehuetenango region of Guatemala and has remained in the family since.
Nowadays, alongside his mother and sisters, Leonardo Rene Perez Hidalgo works hard to improve the farm on a daily basis. Leonardo Rene is the 5th generation farmer, and has been working on the family farm for the last 20 years. He is constantly developing new methods to cultivate more productive and resistant plants more efficiently.
He grows Caturra plants that are not grafted with Robusta. Throughout Guatemala it has been common practice for many varietals to be grafted with Caturra, therefore this is quite an extraordinary characteristics.
The love for coffee and passion for excellence fuels the family’s age–old dedication to the coffee they produce.
The lot featured on Nero Scuro Specialty Coffees has been called “El Eden” and shows off special flavour characteristics. In the cup this coffee appears to be very sweet, with notes of brown sugar, lemon thyme and hazelnut.
After the strength, which we already discussed on a previous article of this series, it is now time to look into the extraction, which is the second quantitative dimension to define an espresso cup.
If the strength is not, according to its definition, related to the amount of coffee grounds used for the preparation (i.e. the dose), the matter is different as far as the extraction is concerned.
The extraction is the ratio between the dose weight and the weight of coffee solids that end up in the cup throughout the preparation.
A high extraction highlights that a substantial amount of coffee soluble solids was transferred by the water flow from the filter into the cup. On the contrary a low extraction indicates that the soluble were transferred into the cup to a lesser extent. The extraction is therefore, in a sense, a measure of the effectiveness of the espresso production process. For a given dose an espresso is more extracted than another if during its production process a higher amount of coffee solids have been pushed from the filter to the cup, regardless of how much water was required to make it happen.
Once again, the extraction is measurable by weighing the dose before preparing the espresso and measuring the TDS in the cup, using a refractometer, after the preparation. The extraction percentage, that is, the proportion of coffee solids transported into the cup, can be determined with the following formula:
Notice that the extraction percentage, precisely because it does measure the efficiency as opposed to effectiveness, depends on the amount of water used to transfer the soluble components from the dose to the cup.
Since the coffee is made for about 28% of soluble solids, in theory one could obtain a maximum extraction of approximately 28%. It is also evident that this would require several minutes, if not hours or days, to happen. As a consequence, the obtained “espresso” would be far more, by weight, than the few grams of a normal cup (probably would be a bucket or a demijohn!) and the strength would be nearly none.
A strong coffee therefore is not necessarily highly extracted and a highly extracted coffee is not necessarily very strong. As in several real life situations efficiency and effectiveness cannot be optimized simultaneously but are rather subject to a Pareto equilibrium, the extraction and strength are in trade-off: an increase in the percentage extracted generally determines a reduction in the strength and vice versa.
This universal truth, on which we will return in the next post, is determined by the fact that the amount of dissolved solids is in fact a non-linear function of the extraction time, of the water flowing through the dose, as well as their smell and taste characteristics vary during the extraction. The perfect cup therefore is a search for a perfect balance between strength and extraction.
See you next year with the third installment of this series!
We're having some changes on the roasting dates over the Christmas period. We'll roast:
----- Closed for Christmas Holidays from the 30th to the 6th of January-----
New and exciting single origin coffees arriving soon! Treat yourself to something good or find the perfect Christmas gift for your beloved ones.
Although there is no universal recipe to get the “perfect” espresso, it is accepted, as much as obvious, that some cups are better than others. Which are the determinants of the espresso quality? Would it be possible to measure some characteristics of an espresso in order to make it repeatable, like the recipe of an Italian tiramisu cake?
In this article, and in the followings of this series, we want to recap some key points of the espresso theory, trying to answer the questions above.
In general, a good espresso is the result of a delicate balance amongst a large number of elements, not least the type of coffee, the roasting profile and a number of personal preferences. However, it has been proved in the 50s, that some well-identified measurable dimensions to characterize the espresso do exist (*). Depending on the value they assume, an espresso may be acceptable, or not, to the majority of the drinkers. These dimensions are the strength and the extraction.
The strength of an espresso is qualitatively associated with facets such as "body", "density", "robustness" and others. A coffee very "strong" is generally creamy, fortified, with a lot of flavor and much body, though not necessarily with a pleasant taste. A less strong coffee is watered down and fluid, with less body and with subtler flavors, less definite, though not necessarily unpleasant.
From a quantitative standpoint, the strength of a certain quantity of espresso can be measured by the ratio between the amount of solids and the amount of water by which is composed, or more generally by the weight of dissolved solids into the cup as a percentage of the total espresso weight. Therefore, to measure the espresso strength is necessary to measure the amount of dissolved solids (TDS - Total Dissolved Solids) and weight of the espresso into the cup.
The espresso weight can be quantified very easily using a scale. The TDS can be measured less easily but accurately by using a refractometer, an essential – although not exactly cheap – tool. We will devote a future article on this blog to describe more in detail what a refractometer is, why it is useful and how to use it.
If two espressos weight the same, the stronger one is composed by a greater amount of dissolved solids and by a smaller amount of water compared to the weaker espresso. In other words, a stronger espresso is the result of a minimal quantity of water being able to move a substantial amount of coffee solids into the cup: the strength is a measure of efficiency of the espresso production process.
But how do these solids turn out into the cup? They are transported by the water (under about 9 bar of pressure exercised by the espresso machine pump) through the coffee tile (the dose), incorporating some soluble components during the extraction process, transporting them into the cup.
The dissolved compounds vary considerably in nature, quantity and characteristics during the extraction. The roasting process produces a huge variety of aromatic compounds (over 800), mainly through continuous amino acids non-enzymatic reduction reactions (Maillard reactions).
As soon as the water starts to percolate through the dose the more soluble components are immediately dissolved and transported. These include various types of acids most of which taste pleasantly, giving the characteristic fruity flavor traits to the coffee. Even earlier, all the salt compounds are dissolved and immediately transported into the cup.
Such compounds run out in a few seconds, and their specific concentration in the water that runs through the filter progressively decreases. Other components with lower solubility start to get increasingly dissolved and become predominant.
For example, almost all of the sugars in the green coffee are caramelized in the final stage of the roasting process. Depending on the roasting degree, their extraction determines the flavor from sweet to bitter (the latter in case of dark roasts, where the caramelized sugars started to enter into a pyrolitic process).
If the extraction is further progressed, polyphenols and caffeine will be among the last to dissolve in water and to be drawn into the cup. They give bitter and astringent notes to the coffee, covering and overhanging sugars. That's why a very strong coffee may not necessarily be pleasant: it depends on what specific solid water has "dragged along".
See you soon with the second article of this series!
(*) All the concepts are in reality applicable to any kind of extractions.