发信人: pstam(喀法教授)
整理人: hyz1216(2003-12-27 00:47:17), 站内信件
|
The espresso is simultaneously a solution of sugars, caffeine, acids, and proteins, an emulsion of oils and colloids and a suspension of coffee particles and bubbles of carbon dioxide gas. Because of the high pressure of the extraction, about ten percent of the oils are emulsified and the aromas attach themselves to the fats, which explains the fragrance of the aromas. The oils are partly responsible for the body of the coffee. This oil-fat arrangement gives espresso a velvety feel when sipped. Also, high viscosity lowers surface tension allowing deeper penetration into the taste buds. Thus, increasing the taste perception.
The pressure needed to force the water through the coffee grains increases with the fineness of the grind and the degree of compression. The higher the compression used, the more complete the flavor extractions.
The term "espresso" is some what ambiguous. This is probably because espresso means different things in the various languages in Europe. As it turns out, there is no probably about it. The following explanation was given in this section of the site from 1996 to the end of 1997. Just because of the story, it makes for interesting reading, and it may be true, but unlikely, as such, it is kept here.
Generally, the word is used to describe any coffee which is brewed by steam. Generally, it was thought that the word expresso meant fast or straight through. Factually, espresso is anything but a fast cup of coffee. Another meaning was interpreted from the word expire. Which, after drinking several of these cups of coffee, people did. The jolt to the system of unsuspecting coffee drinkers must have been enormous. Heart attacks expired people. The general meaning is believed to be "expressly for you." Meaning, this small cup of coffee is made just for you.
Francesco and Riccardo Illy, well known Italian coffee people state in their book "From Coffee to Espresso" the literal meaning of the (world) "espresso" is "made on the spur of the minute." Now, I hope the word "world" is an error and they meant "word." Well, if not, they screwed up, which doesn't say much. On the other hand, world may mean something in Italian which I don't get. They go on to say; it is an adjective applied to foods and drinks that are made at the moment of asking, and in Italy is chiefly used to describe coffee, so that it has become a noun: when you ask for "an espresso" in a bar or restaurant it always means a coffee. So as far as I interpret these guys, espresso simply means coffee in Italian and has nothing to do with what type of coffee it is. These guys are the authority in the coffee business in Italy, so they aught to know. Sure does add to the ambiguity.
Due to the controversy, or excitement, which every you prefer, over what "espresso" verses "expresso actually is, we looked into the meaning of the words. Depending on which book one reads, here is another meaning:
The first known machine to do this was the idea of Louis Bernard Babaut in 1822. The machine was made commercial by Edward Loysel de Santais in 1843 and demonstrated to the world in the Paris Exposition in 1855. The machine packed a measured amount of coffee grinds in a special chamber, a valve allowed steam to press the water through the grinds with a special filter and wa-la, a cup of coffee ready to drink is made. It is fast. The 1855 Paris model was said to produce 1000 cups an hour. Thus, express was associated with the machine.
This particular coffee machine had several drawbacks. One drawback is it blew up from time to time. A steam fitting failed, or the chamber failed, or some bozo let it get too hot. Another drawback is it burnt the coffee from time to time. Especially if a bozo allowed the steam chamber to get too hot. The typical steam pressure was 1.5 to 2 atmospheres and increasing the pressure made for better extraction but burnt the coffee but a lot of bozos did it any way.
The device did work however. Additionally, it produced a superior cup of coffee when operated correctly. The reason it produced a superior cup of coffee is it extracted only the best from the coffee grind. The high pressure forced the water through the coffee grind rather than merely contacting it. This allowed some of the coffee to become emulsified. As the volatile aromas tend to attach themselves after roasting to fatty substances, emulsification drew out these substances and made the coffee smell better along with better body. The cup of coffee had a velvety texture.
Because the liquids viscosity is lower it has a lower surface tension, which allows the liquid to penetrate the gustatory papillae more deeply. Consequently increasing the perception of coffee flavor. The presence of tiny bubbles of gas in suspension and emulsified colloids, mostly carbon dioxide, has the property of inhibiting the receptors of bitter taste in the gustatory papillae. Thus, the flavor taste tends not to be overly bitter. Additionally, the colloids and oil emulsified in tiny drops is responsible the finish by allowing the oils to penetrate deeper into the gustatory papillae which allows slower release of the aromatic substances attached to it.
Making espresso in the old days was a real art. The degree of roast, right grind size, the correct grind packing, the steam pressure, and the quantity of water use were all important. The old espresso machines allowed for much variance. Merchants who wanted to save on coffee beans simply used less grounds causing the forced water pressure not to totally penetrate the coffee grind. Merchants who wanted to give a larger cup of coffee simply allowed more water to go through the system thus diluted the brew and extracted more unwanted substances. So, to do it right, really required skill, knowledge, and interpretation on the part of the operator, thus, it truly qualified as an art.
Expresso is an English invented word to better describe the action of a particular type of espresso machine. Truly the word itself as it pertains to coffee is interesting. The Webster's New Twentieth Century Dictionary has Expresso as meaning Espresso. In the studying of this project, the word expresso popped up many times with some very peculiar adaptations.
Arguments for the word as being bogus or a non-word were very prevalent. It was argued that the "x" wasn't even in the Italian language, then argued that Italians used a latin dialect which did have the "x" in it. However, the word is used a lot for not being a word. Like the word engineer, my pet peeve, expresso is an adaptation to fit a circumstance. Real engineers understand what happened to the word engineer and I bet real espresso inventors know where expresso came form.
Espresso machines were driven by steam. The two drawbacks, blowing up and burning the coffee, needed fixing. It was found by experiment that the two main components of good chemical action occurred at 90 +/- 2 degrees Celsius (190 - 196 degrees Fahrenheit) and 9-10 atmospheres (140 pounds per square inch). As the typical espresso machine was difficult enough at 2 atmospheres of steam, hotter both fried the beans and blew up constantly. In 1935, Francesco Illy, an Italian invented a machine called the Illetta which controlled these factors. Obviously, the machine's name is an adaptation of the inventors name.
The Illetta solved the to problems of the old espresso machines. The way the Illetta did this was to use mechanical advantage from air pressure as a source of pressure rather than steam to force the water into the grind. This solved three problems. The first was the exploding problem. Although air pressure was rather complicated and expensive it was more controllable than steam. Second, since there was no steam, the coffee did not get burnt. Steam was not the source of force so the water temperature could be held constant below boiling. And third, because the cylinder used could be made to precisely control the amount of water to maximize extraction for a given size of coffee grounds, the precise amount of water to maximize the extraction was done automatically.
Later, in 1945, the system was simplified by a machine called the Gaggia coffee machine. This created the pressure by lever action on a cylinder of water to force the water into the grind holder. Around the 1970's, Ernesto Illy further simplified the whole device and introduced the Espresso Coffee System. This coffee system incorporated the best of previous machines, added two layers of filter paper, and generally made the device simple, cheaper, and idiot proof.
One of the last adaptations to this coffee system for commercial and limited home use in 1950 by Ernesto Valente, was the addition of a rotating pump driven by an electric motor to develop the water pressure. This allowed a more continuous delivery of water. An additional commercial development is a rotating coffee grind delivery system so the coffee grinds would be compacted and replaced by the machine too. Thus, the system became almost totally automatic.
Now, back to the word "Expresso." The word "express" means to squeeze; to squeeze out juice, to get by pressure; elicit by force. Other meanings of "express" are high speed, a method of service faster than normal, dispatch swiftly. And, yet a third meaning of "express" is to be explicit; as, his express reason for going, or for the express purpose of running the station. All three of these meanings for the word "express" could be adapted to the way the machine works. It, in fact, squeezes out the juice rather than blows it out. It, in fact, squeezes out the juice in a fast way. And, it, in fact, it squeezes out the juice in a fast way for the explicit purpose of making one cup of coffee. Because espresso was Italian and the English wanted the machine that did this as the word indicates to sound Italian, they added an "o" to the end; thus, expresso.
Expresso, theoretically, is exactly the same cup of espresso coffee. The only difference being the device made to use it. Any coffee made on demand is espresso. But only a cup of coffee made by the precise action of a hydraulic water pressure system as opposed to a steam water pressure system can be called expresso.
Ernesto Illy would probably disagree with this, but he was an Italian. Expresso is an English term. The author is a Californian and half there word are Spanish.
A secondary affect of espresso was the way milk was used. Mousse was term given to this presentation but later turned to froth. Mousse, both adds a smoother taste and minimizes heat loss. There are two types of Mousse. A short floating milk cover and a milk cover with milk mixed in the coffee. This is not a case of just pouring the milk in or on the coffee. The mousse is the correct blend of carbon dioxide bubbles and milk. A special milk blaster was added to the machines in order to create a froth. The color of the mousse should be that of a milk chocolate bar. If it is too dark, this is evidence of over-extraction and if it is too light, then it isn't enough.
A further development in expresso was making multiple expresso cups at one time. In most coffee shops, two people came in. While the second cup is being made, the first is getting cold. Not good from a marketing standpoint. Thus, the two coffee cups at once version caught on quickly at commercial operations. Once two cups could be made at once, four was better. Unfortunately, multiple cups have a waist problem. But, that will be over looked.
So for simplification, the coffee brewer chronology is: First came just coffee and hot water. Then came an espresso maker which forced steam through the coffee grinds. Then came the expresso pneumatic press. The pneumatic press was safer than the steam device by far but it had a volume problem. So multiple cup expresso makers were developed.
If this explanation of espresso verses expresso confuses you, you are not alone. The word espresso can mean any cup of coffee or a cup of coffee made by the steam pressure method, or a cup of coffee made by the squeeze pressure method. It depends on several things, what country you are in, what language you speak, what book you are reading, and who you are listening to. In this web site, expresso and/or espresso means a cup of coffee which is made by water pressure exerted against the coffee grinds by either steam or pneumatic press.
Now at last, the ultimate in easy coffee brewing. It is called instant coffee. Instant coffee is made by brewing it up at a plant, drying it by lowering the temperature pulling a vacuum. Hence the name, freeze dried coffee. After it turns to a dry solid, it is ground, and packaged. When instant coffee grinds are put in water, it rehydrates and becomes coffee.
One of the books I was reading had a story about instant coffee and espresso. The traveler was in Milano Italy and asked for an espresso. May be they had too much of an Italian accent. Any way, to the horror of the person, the bar keep turned, put instant coffee into a cup, poured hot water in it and served it. Oh well. May be espresso really does mean a plain old cup of joe.
The Ship Coffee Brewer is my favorite picture of a coffee brewer. The brewer belongs to: Dr. Ursula Becker, Dr. Becker Klinikgesellschaft; Cologne, Germany.
All in all, the coffee business is ship shape.
----
欢迎加入“喀法咖啡”，除了提供意大利著名企业咖啡和设备，还提供专业咖啡制作和设备操作与维护培训。统一产品，统一质量，统一服务，共同开发中国的意大利咖啡市场。
喀法咖啡 |
|