A great article by Jerry Baldwin, one of the founders of Starbucks:

Many of the more macho coffee drinkers think that all decaffeinated coffee is beside the point. “Why bother?” they ask.

But those who value the taste of coffee as well as the stimulation may disagree. Then, there are those people who, despite their love and appreciation of coffee, can’t tolerate much caffeine; others, who tolerate it well in the early part of the day, can’t sleep if they drink coffee later in the day. Caffeine metabolism varies widely among individuals. Generally, men process caffeine faster than women, especially pregnant women, who are slowest. The liver metabolizes caffeine, so age and liver health also affect one’s tolerance. (See “Caffeine and Decaf” in the curator’s Joy of Coffee, or the Wikipedia entry on caffeine.)

All this brings us to decaffeinated coffee.

All decaffeination methods adversely affect flavor, but careful selection of green beans along with competent roasting and brewing can produce a cup that may fool the experts.

As recently as the mid-’80s, people were drinking more decaf, thinking that caffeine was bad for them. As more and more research showed the health benefits of coffee, people began to switch back to caffeine. Sales of decaf in the late ’80s for some roasters were as high as 25 percent of total coffee sales. Today, among both commercial and specialty roasters, the percentage is more like 10 to 15: lower, but still a significant portion of coffee drinking.

Please suspend any chemo-phobia you may have while reading this. Don’t let the technical words for chemicals put you off, and don’t play into the hands of the irresponsible scare tactics of unscrupulous advertisers of Swiss Water-process decaffeination.

There are four main methods of decaffeination in wide use today, each named for the solvent used: di-hydro-oxide (aka water), ethyl acetate, supercritical CO2, and methylene chloride (dichloromethane in Europe). Even if you remember your high school chemistry, the words may be unfamiliar, but keep that chemo-phobia in check. (A new method using ultraviolet light is coming to the market. Don’t get your hopes up–poor flavor, so far.)

All methods produce a range of quality primarily due to bean selection (garbage in = garbage out) and process temperature, which affects the speed and thus the cost of processing. The American standard for decaffeinated coffee is to remove 97 percent of the original caffeine. Since caffeine content of individual coffees varies widely (see my earlier post on the topic), the amount of residual caffeine will also vary. Unfortunately, all decaffeination methods adversely affect flavor, but careful selection of green beans along with competent roasting and brewing can produce a cup that may fool the experts.

For decades, we have preferred coffees decaffeinated with methylene chloride (MC) because time after time, year after year, they have produced the most flavorful cup. The method is simple enough. First, steam swells the beans to make it easier for the caffeine to be removed. The solvent is then circulated through the beans and then into distillation to remove the caffeine and wax that have been removed from the beans. The cleansed solvent is recirculated and re-distilled until the caffeine has been removed. The beans are then rinsed with water and vacuum-dried.

The most sensitive test for detecting residual MC detects as little as one part per million. I have never seen a test result that detects any amount in specialty decaf. Furthermore, the boiling point of the solvent is 104 degrees F and coffee is roasted at 375 to 425 degrees F. Any remaining solvent, if there were any, would be vaporized during roasting. MC has been eliminated from cosmetics and has stringent worker safety regulations in Europe, but the procedures used in coffee processing and roasting leave nothing to cause any concern.

Most important, after safety, is taste. MC is the most selective solvent, leaving the greatest coffee flavor in the beans.

We have also cupped many samples that have been decaffeinated using either ethyl acetate or carbon dioxide (CO2). Neither method has consistently produced satisfying flavor in the cup. Ethyl acetate, a synthetic fruit ester, leaves a fruity aftertaste in the coffee–unfortunately nothing like the berry and citrus flavors we find in East African coffees. And we had high hopes for the CO2 process in the early ’90s. Carbon dioxide is the carbonation in sparkling water, but it is forced into the coffee at pressures well in excess of 1000 pounds per square inch to extract the caffeine. Perhaps it’s the pressure that also forces out the coffee flavor.

The last method to discuss is dihydro-oxide–water. At one time, water process was the most damaging to coffee flavor. That general statement is no longer true, due to improvements in the processing by some companies. Although some water-process decaf has flavor approaching methylene chloride (and a relatively new North American company is making great strides in cup quality), further development will be required before it can be methylene chloride’s equal.

In general the process uses water as the solvent, supersaturated with soluble solids from green coffee beans, except caffeine. The idea is that when the warm solvent is circulated through the coffee, it will extract only caffeine, which in turn is removed from the circulating fluid with activated carbon. It’s a thesis that in practice has not produced great cups of decaf.

The old standby water decaffeination company, Swiss Water (the only attempt to brand a process), of Vancouver, Canada, is doing all the advertising while others are improving their process. We prefer the cup quality of other companies, and I deplore the marketing tactics of Swiss Water.

In the late ’80s, when I first wrote to the previous owners, I decried their deliberately misleading advertising. Here they go again. They are falling back into advertising tactics that assume the ignorance of the audience. Their attempt to associate the chemical names of the other processes with some chemo-hysteria is unethical.

To summarize, of the four major processes for decaf, only methylene chloride and water are widely used in specialty coffee (here, by the way, Wikipedia on decaffeination is less strong than it is on caffeine). Methylene chloride can produce the best cup results when good coffee and careful processing are used. Good coffee and careful processing also produce the best results from dihydro-oxide, but the best is still second in cup quality to MC.

Source: http://food.theatlantic.com/coffee-culture/in-defense-of-decaff-1.php

Forum Discussion

Introduction

I had been contemplating doing a PID and rotary pump conversion on my Brewtus II for some time. Feeling rather inspired by the guys at Ministry Grounds rotary conversion project, some articles on the Home Barista web site as well as a lot of discussion on the Bretwus email list about the conversions, I was almost ready when, I heard a rumour about a new Brewtus being released, knowing the limited extent of my own handyman skills, I decided to wait a bit and see what the guys from Creme produced. After 5 days with the new Brewtus , I can say that I am well impressed so far.

Differences 

Visually the Brewtus II and III are almost identical, the only real visual clues to the differences are the slightly different temperature display and the changed power switch and to be totally host, I actually prefer the old power switch, a nice big lighted red one :-) and the nice BIG digits on the old temp display, the new PID controller has smaller digits. 

The major changes are all under the skin and they do seem to make a significant difference to the machine.

The first thing that will strike an existing Bretwus owners using the machine is how quite the machine is. The rotary pump is extremely smooth and civilised, none of the vibrating of the Enka in the Bretwus II, this makes a huge difference to the amount of noise the machine makes.

The next thing that struck me was how quickly the shot starts appearing. I have been used to flushing, pulling the lever and then, in a relaxed fashion, emptying my cup of hot water into the sink and placing it under the portafilter, ready to receive an awesome espresso. I used to have 15-20 seconds to get ready for the shot. No longer I am afraid, the rotary pump ramps the pressure up a whole load faster with the espresso starting to appear around 5-10 seconds after pulling the lever. So things happen faster. 

I haven't done a head to head comparison yet but the steam pressure also seems to be held better. I haven't done any tests yet but my feeling is that the Brewtus III seems to be able to hold a higher steam pressure than the II when steaming. This is something that I am going to have to check out in a bit more detail so I can comment better on. 

As I am currently waiting for a water pipe, I don't have it  plumbed in as yet, so am unable to comment on the pre-infusion of the E61 group head but once it is I think this is also going to be interesting to experiment with. Something which I was unable to do with my tank run II.

So, how does the coffee compare? Well, the Brewtus II is no slouch, they are able to produce excellent espresso's with a minimum of fuss. The III definately caries on this tradition and just lifts the bar to even greater heights.

Issues

The only two issues that I could find on the new machine, is a difficult to access brew pressure regulator. The adjustment is on the side of the pump which is facing the boiler, not a major problem but one none the less, and a water supply pipe to the rotary pump that faces upward in the machine but exits the machine at the bottom. If the pipe is pulled, it can create a kink which restricts water supply to the pump.

Conclusion

The Brewtus III definately offers fantastic value for money, its only real competitors in SA being the La Marzocco GS3 and the La Spaziale Vivaldi II. Both machines are significantly more expensive and while I lust after a GS3, I don't think I could justify paying almost twice as much as the Brewtus III for one. The La Spaz used to have the advantage of having a rotary pump but with the III also having a rotary, I don't see any motivation to go there either.

For a home barista looking at a high end home machine, you can't go wrong with the Brewtus III, it offers the rock solid temperature stability of a double boiler machine coupled with a PID controller along with the great water delivery of a rotary pump. All that is required to ensure awesome espressos is a good grinder, some fresh coffee and a modicum of barista skills.

Answers to some questions

- What is a PID controller ?

- Espresso machine guide?

Arstechnica Article

By Yun Xie | Published: November 25, 2008 - 01:36PM CT

Used coffee grounds may be garbage to most of us but, to chemical engineers at University of Nevada, they are a versatile source of green energy. Narasimharao Kondamudi, Susanta Mohapatra, and Mano Misra proposed that the solid waste from coffee brewing can do a lot more than act as compost for gardens. They set out to see if they could extract oils from old coffee grounds and chemically convert those oils to biodiesel.

Image Credit: Ragesoss. 

Spent coffee grounds are about 15 percent oil, which is only slightly less than many of the other biodiesel feedstocks. Since the world produces over 16 billion pounds of coffee per year, there is a constant and cheap supply of solid coffee waste. Kondamudi, Mohapatra, and Misra also predict that biodiesel from coffee grounds would be more stable than those from other sources because coffee contains antioxidants that would slow down degradation.

The researchers extracted oils from Starbuck's spent coffee grounds, and went on to perform a standard transesterification process to convert the oil to biodiesel using methanol (a type of alcohol) and potassium hydroxide (a base for catalyzing the reaction). They were able to convert 100 percent of the oil in the grounds into biodiesel; both the extracted oil and biodiesel were stable for more than a month, which is sufficient for industrial applications.

Ground Coffee. 

After the oil is extracted, the grounds can still be used for compost or fuel pellets. The authors estimated that, if spent grounds were converted into biodiesel and fuel pellets in the U.S., it’s possible to make about $8 million in profit per year. On a worldwide scale, based on the amount of coffee that is used, 340 million gallons of biodiesel can be produced from spent grounds.

The authors showed that used coffee grounds are much more than a waste product and can be a source of green energy. Of course, to know if this process is truly green, every step of the conversion would need to be analyzed in detail, but the initial results are promising, especially given that the waste products from the process can be used further as compost or fuel pellets.

Journal of Agricultural and Food Chemistry, 2008. DOI: 10.1021/jf802487s