Coffee Machine Choice
Firstly – why get a machine? What’s wrong with a percolator or a stove top moka pot?.. The very basic answer is that coffee from a percolator or a moka pot tastes like complete toilet when compared with what can be achieved using a good quality coffee machine.
But the machines cost so much – I can’t afford it… – Can you afford to insult your taste buds twice a day while you wince through gulping down a cup of bitter swill?… Life is far too short – food (and beverages for that matter) is one of the great wonders of day to day life – you truly can look forward to something that tastes amazing that has been created with great attention to detail and flair. Coffee really does fall into this category – but it’s better because once you’re set up, the cost to achieve perfection is around 40 to 50 cents. For most (me included), it becomes something of a temporary escape from day to day life…
So… spend some money and set yourself up, ready to start enjoying that something very special every day – you won’t regret it.
Now the nuts and bolts – where do you spend your money, where do you not spend your money and what justifies both avenues of thought – as I assure you, all machines are NOT created equal…
Forget about auto anything to start with. With current technology, auto machines will never adjust or compensate as well as you would be able to for any changing conditions – new beans, aged beans, tamping, dosing, grind adjustments, extraction times / amounts, brew temperature, etc, etc, etc. I’m not a fan…. For what you get – they also tend to be very expensive. But, for your average Joe who doesn’t have the time to commit to creating quality coffee as yet, an auto might be a perfect fit for your start in this great industry. For anyone else though – auto should describe the transmission in your car and nothing else…
Strip off all the bells and whistles on offer in the market place with machines and basically, once you have the perfect and very capable grinder (see the previous article on grinders) – what you need is a machine that can provide a controllable extraction amount at a stable brew temperature that is adjustable. Everything else – including brew pressure adjustability to a degree (whilst appearing very useful and appealing) is pretty much window dressing relative to a high quality and repeatable cup of delicious coffee. There are other useful features (steam pressure, etc) that apply when considering milk texturing, etc – but these are of no use if you cannot pull a perfect shot of coffee in the first place..…
We’ll jump around a bit for a while here (mainly because I have so much to cover and can’t decide where to start…).
The amount of liquid you extract from a puck of coffee (the compressed grinds in your portafilter) into your cup below is very important. The basics are as follows – if you under extract (i.e. less than the optimum amount of liquid), the taste can be somewhat sour. If you over extract (running too much liquid through your puck), the taste WILL be bitter. Again, some people like their coffee to taste ‘off the charts’ bitter – if so, order your beans burnt to hell during its roasting phase and you don’t need to worry about this whole article…
When you turn the machine’s pump on to perform an extraction, it will build up the water pressure above the puck at a set rate (‘rate’ adjustable on better machines through various applications such as jet sizing and pump cycling – forms part of the pre-infusion routine). After a short amount of time (seconds) under a fairly extreme amount of water pressure (9 bar or about 130psi), the very first part of the liquid extraction appears from the underside of the compressed puck – slowly dripping out from the spout opening at the base of your portafilter. This first amount of the extraction liquid that comes out is slightly sour, the middle portion is sweet (or at least as sweet as the bean has to offer) and the rest is pure toilet water. This comes about for several reasons – but basically it relates to the particular acids being leached out from the puck of coffee at each particular segment time during the extraction process (refer previous articles on brew temperatures).
Hopefully you are using fresh beans that have some level of crema showing during the extraction. Crema is basically the aerated portion of the extraction emulsion that is a by product of the extraction process which settles on the surface of the extracted liquid down in your cup below. Not all beans produce thick crema – so this is not always a perfect indicator of a bean’s quality or freshness – but it can certainly help you to fault find during your extraction. Its taste quite often will be perceived to be bitter – this is not actually the case. The crema has the same flavour intensity as the rest of the original shot. Consumers will then add water or milk to the shot, leaving a level of the crema on top. Because this crema has not mixed in with the rest of the coffee beverage, it is still at the original full strength from when it was extracted – thus the reason why it is sometimes perceived as being bitter.
Now, back to why crema is useful – it assists in showing you when to stop your extraction. The crema appears dark brown initially, changing to lighter brown as the extraction continues. Eventually, it will have streaks of blonde colours in the stream – this is when it’s time to stop. ‘But there’s not enough in my cup’ I hear you say…. If you value taste over quantity, use a smaller cup to achieve the strength level you are chasing – otherwise, keep extracting & then add a couple of teaspoons of instant coffee and a pound of sugar – because you aren’t going to taste any difference and honestly, you obviously don’t care about what you drink anyway…
Brew Pressure Adjustability
Brew pressure adjustability is important (not as important as the essentials listed in an earlier paragraph) because it can offer levels of flexibility and a bit of extra control over the extraction process. Differences in pressure on the puck (the compressed grinds of coffee) throughout the extraction will affect the taste level and complexity within the cup – assuming the grind settings remain the same. This is something for you to play with that gives you greater options to get what you perceive as the best tasting extraction possible. Think about the extraction process – when the first liquid passes through the puck, it takes a great deal of flavour & oils with it into your cup. As the extraction continues, the extracted flavours quickly reduce – until an opaque bitter yellow stream is pouring out. The old style manual lever machines (quite a few are still made today commercially) overcome this to a degree by using spring pressure. When you start your extraction, the spring pressure is at is highest, as the extraction process progresses, the spring pressure reduces, reducing the liquid pressure & the consequent flow rate down as it passes through the puck – allowing it more soak & extraction time to draw every last bit of flavour out – really clever actually. Some current commercial & semi commercial machines also achieve this through programming pump rates and jet alternating – but the older style lever machines provide the greatest representation of this process.
Don’t get me wrong, these spring pressure lever machines don’t necessarily produce a better cup than machines that have a constant brew pressure profile do – it just produces a different cup. It’s up to you if it is actually ‘your’ different style of cup.
Anyway – back to how brew pressure allows flexibility. Your standard setting on most machines is somewhere around 9 bar. This will produce a shot of coffee in ‘x’ time. You can alter this amount of time through four main factors – grind setting, tamp pressure (to a minor degree), dose level in the basket and brew pressure.
I have found something interesting through experimentation. If you lower your brew pressure, there seems to be a lesser amount of resultant flavour in your cup. If you raise the brew pressure, it seems to squeeze out more flavours. Obviously, you need to adjust your grind setting to match the brew pressure – but this result actually makes sense – If your grinds are super fine, they have more surface area overall to lose flavour from – the water will not need to penetrate very far into each grind to pull every bit of flavour from it. If your machine is capable of brew pressure adjustment – please give this a crack and play around with it. My bench top testing machine is set to 10 bar – and does a magnificent job at that level.
Brew Temperature Control
Stable and adjustable brew temperature on the extraction is possibly more important than anything else on the machine. An important note to remember is that your machine’s temperature reading does not need to be accurate to anything – it is just a number. What it needs to do though is to be stable and adjustable by small increments. If your machine shows 88°C and is super sweet in taste – then that’s perfect. Another identically branded machine may show 90°C and provide the same results – so what?… So long as you can determine whether what you are tasting is sour, sweet or bitter and adjust the machine accordingly, you are going to have a win – it really is that simple. The machine’s brew temperature must be as stable as possible throughout the extraction – as a variance of just 1°C makes a significant change to end taste. The following demonstrates how temperature effects taste –
Cooler = More Sour. Hotter = More Bitter. Middle = Sweetest.
– Simple….(assuming your palate can discern moderate changes between each). You can have a bad day, misinterpreting sour for bitter and vice versa – resulting in you adjusting your machine over and over again, pulling shots of coffee that belong in the toilet and after an hour of bashing your head into the wall, you’re so wired from the caffeine in your veins, you could drive a car for 24 hours non stop. Give it a rest, reset your machine back to a median setting (usually between 92 and 94 degrees Celsius) and start again tomorrow….
As you work through the different temperature settings, don’t adjust your machine & try a shot straight away. The machine needs to warm up everything between the element and the outlet in order for you to make an accurate judgement. Don’t forget to warm your machine up sufficiently beforehand too – this can take 20 to 30 minutes.
I once read a post where this lad tried everything to make the first shot out of his machine taste great – by getting rid of the old grinds, run warming flushes through the machine, leave the portafilter in the machine during warm up, etc, etc…
He received tons of replies & advice – most of which reiterated what he had already tried… So, here it is (the solution to making that first shot taste sublime) – coming from a 6 to 18 shot per day for years drinker and roaster – I have a machine with a PID. This allows temperature adjustments of 1 degree celsius. Each bean requires slightly different temperatures to get the best out of a particular variety and roast level. So, what you do is to overheat the machine (by as much as 2 degrees compared to your normal brew temperature), run several long shots through over a period whilst it is up to temperature – making sure everything along the line is super hot. You will then either extract at that point for just your first shot & then revert back to your normal set temperature – or – you’ll drop the temp back to the correct setting immediately before your first shot and then do the extraction – it is that simple. The times, flush volumes and frequency and temperature settings all require some trial and error on your part – but, when you have it you can hit an amazing shot first time out of your machine – saving screwed up faces and wasted dollars going down the sink. Unfortunately, the perfect recipe will vary from machine to machine and bean to bean – but, without doubt it can be done – and is done about 9 times out of 10 on my machine – and can I suggest that I am ‘slightly’ fussy about flavours….
Brew Temperature Stability
Another important design aspect of a machine is to have the shortest run possible between the brew boiler and the outlet. This, when combined with a large thermal mass of the grouphead all assist in achieving a more stable brew temperature profile. These aims have been achieved in several ways be several manufacturers. Firstly, having the outlet close to the brew boiler – there is a shot volume flow control valve installed on machines the measures how much water is emitted for a particular setting on your machine. Previously (with the aim of being more accurate), manufacturers had installed these between the boiler and the outlet – creating another point where the brew water can lose temperature. This has been mostly resolved through the realisation that water is non-compressible. This means that regardless of where this flow control meter is installed, so long as it is a completely filled closed system, the set dose level will be constant. With this in mind, manufacturers are installing these items before the brew boiler at their inlet instead of the outlet.
A method used to help maintain the water temperature after leaving the brew boiler that has been employed is to use a grouphead that is made of very thick metal (such as the e61 grouphead – pioneered by Faema in 1961 funnily enough). These groupheads weigh approximately 4.5kg’s and are made of solid brass, usually covered in polished chrome to look fancy. They take quite a time to heat thoroughly, but once heated, they will maintain their temperature very well. The brew water flows through a maze of channelling in the centre of these, remaining hot all the way.
Another clever method of maintaining a stable brew temperature is to incorporate a water channel within the grouphead mass that is a direct part of the brew boiler – thereby creating what’s known as a saturated brewing group. This water is held at the same temperature as the brew boiler – therefore maintaining the grouphead at the same temperature also.
Current Market Machines
You do tend to pay good money for such ‘fanciness’ – but perhaps not as much as you may think in some cases… Here is a short list from least most expensive (that is capable of delivering fine coffee – when matched with a superb grinder (see the article on grinders)) to the most expensive – based on a level that will shine in a home environment and in the case of the most expensive machine listed below – excel.
Sunbeam café series EM7000
– on special from around $500 right up to a retail of about $800. It has brew temperature adjustment, steam temperature adjustment and steam pump rate adjustment. It has single wall baskets and various programmable volumetric dosing buttons. Once warmed up properly, it will do a job that is capable of matching or beating about 50% of the average ‘run of the mill’ cafes out there – great ‘bang for buck’ and will produce a cup that will impress.
– somewhere near the $1,200 mark at the moment. This has all that the sunbeam has plus it will adjust the temperature in 1 degree increments, adjustable preinfusion settings, adjustable brew pressure settings and its steam pressure is higher than the sunbeam’s. This machine is capable of matching some quite reasonable commercial machines – not completely – but certainly enough to satisfy the home drinker. It has a lot of ‘options’ to play around with in order to fine tune what you’re tasting in the cup. I would rate it as being quite superior to the already good Sunbeam above. Worth the money.
Expobar Minore 4 (or known as the Brewtus 4)
– goes for around the $2,500 mark. It has all the features of the Breville (except preinfusion is not adjustable as it is achieved via mechanical methods through channelling within the e61 grouphead). The big difference for this one is in the quality of the componentry – it is designed for use in small cafes and would last the home user up to 20 years. It is a very solid workhorse and compares favourable with machines costing nearly 3 times as much – as in a reviewer could not discern a difference in flavours of shots that were blind tasted between this and 2 other much more expensive machines. Bang for buck – this would be my choice (and it was, until I upgraded to a full commercial machine). This machine could match nearly 90% of cafes that I have ever visited – some through outright capability, others through barista inability. It can pull a magnificent shot of coffee and is pretty well as far as a home enthusiast ever need tread. It has everything you need and performs exceptionally well. It also looks fancy – if that’s your thing…
I touched earlier on not over or under extracting a puck – as doing so will render your shot undrinkable. Some machines can assist with a level of repeatability of the correct shot volume to save you worrying about it each time. These machines are classed as semi-auto and have what is known as volumetric shot control buttons that can be simply programmed by you. These then allow you to achieve the correct level of extraction every time by just pushing a button once and then the machine will dispense the correct amount of liquid automatically.
There is one caveat with this – if you change beans, change grind coarseness or if your beans become more stale, you may need to recalibrate the setting for this button – as your coffee will gradually start to taste ordinary due to over or under extracting and without careful monitoring, this may go unnoticed – and it is such an easy thing to rectify and makes such a huge difference. This is a handy feature to have on your machine.
I think I have covered most of the important functions you should chase within a machine and why they are important. If you feel I have missed anything – or were scant on detail, add something below in the comments section…. Cheers.