Swiss water process
The Swiss Water Process is a method of decaffeinating coffee beans that was developed by the Swiss Water Decaffeinated Coffee Company. To decaffeinate the coffee bean by the Swiss Water method, a batch of green (unroasted) beans is soaked in hot water, releasing caffeine. This process is done until all the caffeine and coffee solids are released into the water. These beans are then discarded. Next, the water passes through a carbon filter which traps the caffeine molecules but allows the water and the coffee solids to pass through. The caffeine-free water which comes through, known as “flavor-charged” water by the company, is then put in a similar filtration device, and new coffee beans are added. However, since the flavor-charged water cannot remove any of the coffee solids from the new beans, only the caffeine is released. The process repeats, filtering out all the caffeine until the beans are 99.9% caffeine free. These beans are removed and dried, and thus retain most if not all of their flavour and smell.
In the direct method the coffee beans are first steamed for 30 minutes and then repeatedly rinsed with either methylene chloride or ethyl acetate for about 10 hours. The solvent is then drained away and the beans steamed for an additional 10 hours to remove any residual solvent. Sometimes coffees which are decaffeinated using ethyl acetate are referred to as naturally processed because ethyl acetate can be derived from various fruits or vegetables. However, for the purpose of decaffeination, it is not generally possible to create such a large quantity of ethyl acetate, thus the chemical is synthetically derived.
In the indirect method beans are first soaked in hot water for several hours, essentially making a strong pot of coffee. Then the beans are removed and either methylene chloride or ethyl acetate is used to extract the caffeine from the waterâ as in other methods, the caffeine can then be separated from the organic solvent by simple evaporation. The same water is recycled through this two-step process with new batches of beans. An equilibrium is reached after several cycles, where the water and the beans have a similar composition except for the caffeine. After this point, the caffeine is the only material removed from the beans, so no coffee strength or other flavorings are lost. Because water is used in the initial phase of this process, sometimes indirect method decaffeination is referred to as “water processed” even though chemicals are used.
This process is technically known as supercritical fluid extraction. With the CO2 process, pre-steamed beans are soaked in a liquid bath of carbon dioxide at 73 to 300 atmospheres. After a thorough soaking, the pressure is reduced allowing the CO2 to evaporate, or the pressurized CO2 is run through either water or charcoal filters to remove the caffeine. The carbon dioxide is then used on another batch of beans. This same process can also be done with oxygen (O2). These liquids work better than water because they are kept in supercritical state near the transition from liquid to gas so that they have the high diffusion of gas and the high density of a liquid. This process has the advantage that it avoids the use of potentially toxic solvents.
Green coffee beans are soaked in a hot water/coffee solution to draw the caffeine to the surface of the beans. Next, the beans are transferred to another container and immersed in coffee oils that were obtained from spent coffee grounds.
After several hours of high temperatures, the triglycerides in the oils remove the caffeine – but not the flavor elements – from the beans. The beans are separated from the oils and dried. The caffeine is removed from the oils, which are reused to decaffeinate another batch of beans. This is a direct contact method of decaffeination.
Yes, we took delivery of this premium Swiss water process decaffeinated coffee today. Tomorrow we hope to run test roasts to profile this coffee. We will also try & post some more information on the Swiss water process of decaffeination and how it differs from CO2 (carbon dioxide) and MC (methyl chloride) decaffeination processes so you can appreciate the differences.
In response to customer requests, this week we expect to receive our Swiss water process decaffeinated coffee from Costa Rica. As soon as it arrives we will add it to our product collection for you.
Why choose Londinium Espresso for your coffee beans? Well, as a mail order coffee roaster the only opportunity we have to influence your opinion of us is through our product. We have no elaborate shop where the aromas of the world’s exotic coffees waft paste your nose as they are ground, no ornate brass ware to measure your beans out in front of your eyes, no attractive sales staff to make you feel as though you will join the social elite if you buy our product. You see, we very much stand or fall on the opinion you form about our product in the privacy of your own home or workplace, uninfluenced by what the ‘expert’ in the shop might be suggesting that you should be able to detect in the roast. And so, there is no room for us to employ puffery or indeed any other claim that is not going to measure up when you first taste our product. Londinium – you be the judge.
Today’s blog merely underlines how serious we are about great coffee. Our promise is that our coffee will give you a better cup of coffee out of your equipment than anyone else’s. Fullstop. Otherwise you get your money back. This isn’t mere puffery. If we didn’t believe this was the case we never would have started Londinium Espresso as we wouldn’t have had a unique selling point. We are incredibly fussy about the beans choose to stock, buying a single bag to test, before ordering a larger quantity. The household brands in coffee have a finished product cost that is considerably less than the price we pay for our raw green beans. The only thing our products have in common with theirs is the name. In all other respects they are entirely different. Then we take a lot of care with the roasting process, much of which we have custom built oursselves, as we could not find satisfactory solutions in the market place. Finally we carefully inspect the roasted beans to remove as many defective beans as possible. People who just want a cup hot, bitter-burnt liquid will not see the point in paying a premium for our products. People who would like to discover what coffee tastes like just might. So if you are looking to differentiate your independant cafe from the high street chain cafes, are a business who understands the impression that fine coffee creates with your clients, or a connoisieur purchasing for your private consumption, please try Londinium with confidence. We will be more than happy to return your money in full, in the unlikely event that we do not meet or exceed your expectations. We have travelled the world extensively prior to establishing Londinium Espresso, and are confident that we are purveying some of the finest coffee in the world to our discerning customers.
You simply won’t believe how good this is on the hot afternoons that are forecast to continue all this week. If you can make a great espresso, you can make a great affogato. Take a cappuccino or similar sized cup & place a very generous scoop of fresh creamy vanilla ice-cream (the full cream Devon ice cream is ideal). Then grind your favourite Londinium Espresso coffee, place the cappuccino cup with the ice cream under the group head of your espresso machine, and draw two shots of espresso over the ice cream. Then leave for 2 minutes before eating so the espresso softens the ice cream & the ice cream chills the espresso. Enjoy! We bet you won’t be able to resist a second one. They are the ultimate summer treat.
Today we received from Italy our sample cups. We will be placing an order next week, so look out for them on our website in the not-too-distant future. Espresso just isn’t espresso without the proper thick walled porcelain cup. Yes, there are numerous cheap, thin-walled versions available that we think are simply a corruption. Also have a look at the glaze where the handle is joined to the body of the cup – cheap cups will almost always exhibit pitting in the glaze in this area where air bubbles have formed when the cup has been fired in the kiln. We think these will also make a great gift for the coffee connoisseur in your life. They will also be available in cappuccino and latte sizes, as shown in the photograph.
you might like your coffee strong, but please trust me on this; if you take the finest coffee in the world & make it too strong the delicate, unique flavours that you have gone to so much trouble to acquire will disappear & it will taste like a heavy caramel concoction.
so if you are looking for a starting point, and perhaps it is slightly on the weak side but at least it is an unambiguous measure, i would suggest 3 level desert spoons of freshly ground coffee beans with the isomac grinder set to position 6 (i.e. with the ‘6’ at the front of the grinder) for a cup that will hold 250mL of water.
obviously a finer grind means you need less coffee & vice-versa for a coarser grind.
hope this helps. if you are having trouble, please call & we’ll try & sort it out over the phone
One of my goals in this blog is to de-bunk a few myths about coffee in general, and espresso in particular.
So we can keep this blog entry focused, let’s assume you already have a suitable grinder & machine & coffee.
Firstly, unless you have some magic machine that I haven’t had the opportunity of using yet, dump the first espresso out of the machine, whether it is the first cup when switching on or if the machine has been sitting unused for an hour or more (again just a guideline)
The golden rule I want to establish in this blog is ‘the crema tells you everything’.
The crema on an espresso will tell you whether it is fit to drink without placing the cup anywhere near your lips.
The crema should be light golden colour. I recognise that it is slightly difficult to describe in words & publishing photos leads to chaos as everyone’s screen shows colours slightly differently, but the following guide lines will at least get you into the ‘zone’ of espresso satisfaction, well on your way to nirvana.
Perhaps the easier way to describe the colour of the crema is what it shouldn’t be.
Think of all the possible colours that the crema can adopt as a spectrum, ranging from whitish through the light golden colour already mention then on to the chocolate tones.
This colour spectrum is the espresso’s built-in instrument panel telling you where in the range your espresso lies, all the way from chronically under-extracted (very light whitish tones) to chronically over-extracted (very dark chocolate tones). All you have to do is learn to read it by paying it a little more attention.
Once again, I am reluctant to dish out absolutes as my experience suggest that people’s taste vary a little, but the key thing is to take note of the appearance of the crema before you taste the espresso, then taste it. If you like it, pause & take another good look at the remaining crema & commit it to memory. This is your target for next time.
Before we dive into under & over extracting, and what to do about it, lets talk about keeping the ‘tail’ out of your coffee. What’s the tail I hear you ask?
The tail is just a word I have assigned to the light coloured splodge that will corrupt an otherwise perfectly drawn espresso right at the end. It will also be foamy/bubbly, unlike the extremely fine bubbles of the crema up to that point.
OK, great I hear you say, ‘I have seen that bubbly white splodge on my otherwise perfect crema’ but what can I do about it?
Well if you observe the stream of coffee as it flows from the bottom of the porta-filter you should see that it flows in a fairly continuous shape and then at some point just before the end of the extraction the stream will quaver or change shape. At this precise moment you need to quickly & carefully remove your cup out of the stream (by the time you have turned the button off it will be too late & the tail will still end up in your cup!)
But be careful – don’t stick your eye so close to the machine that you are at risk of hot coffee spurting into your eye. Similarly when you deftly move the coffee out from under the stream do so in a smooth manner, not violently or you will most likely end up with hot coffee on your hand.
So, back to under & over extracting.
ANY WHITISH colour tones in your crema & you are under-extracting. What to do about it? Well, if you are only slightly off try tamping the coffee into the porta-filter with a little more vigour, or possibly place a little more coffee into the porta-filter. If this isn’t enough, then set your grinder to a finer setting & try again. Yes, its trial & error, but not the rocket science that some would want you to believe.
ANY CHOCOLATE colour tones in your crema means it is over-extracted. What to do about it? The opposite of under-extraction. Possibly you have put in too much coffee, although you will usually be aware of this as you will struggle to get the porta-filter to locate onto the machine. More likely you have packed the coffee in with too much vigour. This is the most common scenario when you change to a Londinium coffee for the first time, as the coffee is so much fresher than most other coffee that there is a lot more oil still present in the bean which helps the grinds to stick together, unlike a stale coffee where the oils have long since departed and you are trying to force dry grinds to stick together. Failing that you might have to back your grinder off so it grinds slightly coarser.
...time is up for the moment, but those simple rules should get you well on your way to coffee nirvana.