Martin's Past Musings
One of the questions I am asked about coffee from time to time is to do with acidity. Usually people wanting to know which is the least acidic coffee we do as they have concerns about their diet, or health.
There is, justifiably, some confusion, due to the fact that there are two sorts of acidity when it comes to coffee!
Most of us are familiar with acids and alkali as being a chemical measurement using the pH scale. Ok so here is a schoolboy explanation, not trying to be patronising of course!
The scale goes from 0 to 14. Low numbers are acid, high numbers are alkali. So, at zero we have battery acid, and at 14 we have drain cleaner.
Neutral is 7 and our blood is 7.4, so slightly alkali
Black coffee (of all sorts) is 5 and milk is 6.3 (as is urine by the way), so slightly acid.
Lemons are about 2.
ACID to ALKALI
0 - battery acid
5 - black coffee
6.3 - milk, urine
7.4 - human blood
9 - baking soda
14 - Drain cleaner
So, all black coffee is actually around pH5, The WORD acidity in coffee is more about sensation and less about the science.
The taste may be described as acidy tasting, like citrus fruit, or ‘sharp’, but these are mouthfeel descriptions. So why do they call it ‘acid’ and how can one coffee taste more or less acid than another if there is no chemical scale involved?
There are things which change the perception of acidity and they range from the plant to the brewing method used. Here are a few of the things that will affect the final ‘acidity’ in coffee terms.
To affect the acidity
1 Arabica beans are said to be better the higher above sea level they are grown, and achieve a better ‘balance’ of acidity, but they are less acid if they come from lower heights, so a low grown arabica will be less acid than a higher grown one, but not as highly prized!
2 During the roasting process there are lots (hundreds I am reliably informed) of chemical changes going on inside each bean and as a roaster you seek to make the best outcome for each type of bean which is called profiling (I’m really trying not to be a know it all, or patronising-it’s a tough call, bear with me) As the roast gets darker, the acidity decreases and the sweetness increases, take it a touch too much and it turns to bitter then sour in an instant (no pun intended).
3 For some unfathomable reason, the finer you grind coffee for an espresso, the lower the acidity. If it tastes bitter it will taste the least acidic, which is why some people prefer a bitter espresso.
Nothing is simple. If it is just a chemical question, then there isn't much discernible difference, it’s 5, as I said at the top, but to answer the question, ‘Which is the least acidic (tasting) coffee you sell?’ the short answer is…. Ethiopian Limu, made in a cafetiere! (although there may be others-told you it wasn’t simple!)
Coffee's Origin Myths
The tale of the discovery of the coffee plant is told in a number of origin myths. In one of the most popular Kaldi, an Abyssinian goat herder noticed his goats acting very excited and animated. He also saw that his “dancing goats” were all eating from the same plant, so he decided to try the cherries and found their wonderful properties of making him awake and active. Excited about his discovery, he filled his pockets with cherries and rushed home to his wife, who then encouraged him to share his discovery with the monks.
The monks were not nearly as enthusiastic about coffee as Kaldi and threw them into the fire, decrying them as “devil’s work.” However, the smell of the roasting beans in the fire was so intoxicating that they raked them out of the fire, crushed them to quench the embers and then stored them in water to preserve them.
The other popular origin stories for coffee take place in Yemen. There are actually two Yemenite origin stories for coffee. In one, the Yemenite Sufi mystic Gothul Akbar Nooruddin Abu al-Hasan al-Shadhile was traveling through Ethiopia when he saw some energetic birds who had been eating berries from the bunn plants (the Ethiopian term for the coffee plant). Feeling tired himself, he decided to try them and, discovering that they invigorated him, he brought the news with him along his travels and back to Yemen.
In the other, Sheikh Omar was exiled from Mocha into the wilderness. On the verge of starvation, he found coffee cherries but because they were too bitter to eat raw, he tried roasting and then boiling them. But, when he noticed how good the liquid smelled, he decided to drink the boiling water instead. Discovering coffee’s magic properties of invigoration, he began sharing his newfound knowledge with others. This knowledge soon spread back to Mocha where they quickly revoked his exile and invited him back to the port city to share his revitalizing drink with the city.
Roasting Coffee - A Produced in Northumberland production!
Martin has been sharing his roasting skills with the Produced in Northumberland team!
Storing coffee - Tips and Myths
To Freeze or not to freeze?
I have had many discussions on the merits of freezing along with studying lots of research into the pro’s and con’s.
I have come to the conclusion that it is best not to!
My reasons are as follows:
Regarding moisture; coffee beans and more especially ground coffee will deteriorate much more quickly when exposed to moisture, so a damp environment at any temperature is not recommended.
Commercially, freezers use liquid nitrogen and freeze as near instantaneously as possible.
Domestic freezers however will only freeze slowly and therefore run the risk of creating condensation within the packet as it cools down, and again when it warms up. So moisture is likely to be present as it freezes or defrosts.
During the freezing process, the first thing to freeze is water and their crystals are really sharp and spiky. Any residual moisture within the bean will form very sharp crystals which will puncture the adjoining cells. This is why high moisture content fruit (strawberries for instance) will be dark and mushy when domestically frozen/defrosted.
Freezing only lowers the temperature, it doesn’t stop time, so deterioration will still occur albeit a little more slowly.
If you take out small amounts at a time from the frozen packet it will speed up the deterioration, as you will be introducing oxygen into the packet.
Regarding Oxygen; beans and more especially ground coffee deteriorates quickly in the presence of oxygen. Oxidisation produces ‘rust’ within almost everything.
Freshly roasted coffee exudes carbon dioxide from the point of roasting, quickly at first and then more slowly for about 3-4 days. If it is subsequently ground, there is another ‘burst’ of CO2 for a few hours.
CO2 is a natural preservative and is heavier than air and therefore forms a protective ‘pool’ which is perfectly adequate to bring the deterioration to a minimum, the one way valve in the packet allows oxygen rich ‘air’ to be expelled, therefore raising the percentage volume of CO2 within the packet. This negates the need to freeze. Freezing does nothing to enhance this process.
Should you keep it in the fridge?
As above, all that using a fridge does is increase the potential of condensation. Practically, if you take a packet out to use for breakfast say, and then pop it back in when you are finished, the temperature has risen and then decreased, allowing more potential for condensation than it would have had just being in the cupboard. Coffee is bought and used pretty well all over the world in a wide range of ambient temperatures, the best storage temperature is the one you are making the coffee in!
How long should you keep coffee?
Paradoxically, the best way to preserve coffee beyond its natural peak life span of around 5 weeks and up to 3 months is not to do anything, as it is perfectly capable of looking after itself thank you very much!
If you only purchase enough beans to last for 4-5 weeks, as long as you buy it freshly roasted, there is no need to keep it all, even less reason to freeze it!
Conclusion: As coffee is pretty well available whenever you want it, the best way is to buy small amounts (enough for a max of 2 months) and enjoy it straight away. To encourage people to only buy what they need for a month at most, I offer free postage for as low as £15 (some sites ask you to order lots) which is around 3 x 228g packets. This is enough for the average coffee lover for three weeks to a month.
So,the best way to store coffee is to keep only a month or 2 supply, keep it airtight and upright (conserving its CO2 pool), dry, and at an ambient temperature.
My coffee is superb, I care about what I do, as do most of the other coffee roasters I know. My success is due to my well kept secret, which, as long as you promise not to tell anyone…is Freshness!
Coffee Grinders - Which one should you buy?
One of the most frequent questions I get asked is in regard to coffee grinders.
If you enjoy fresh coffee made at home, then the first choice is usually a cafetiere which is relatively cheap and gives you the satisfaction of brewing your own coffee, the smell, getting the right amount, the right timing, and the excitement of maybe brewing the perfect cup of coffee ( that last bit might just be me though). In coffee world, cafetieres are referred to as a full immersion method. Other stops along the way are the various filter methods, aeropress types, and full on espresso machines. Even if you go straight for a bean to cup machine, it is useful to understand the mechanics of grinding the beans.
I will cover grind size and its importance more fully in another ‘musing’
Back to basics, the biggest step to improving your coffee ‘experience’ is to grind the beans just before you use them. Go into any coffee shop and you will find there is a grinder right next to the coffee machine. This is no accident! Top baristas in competitions will only tolerate a maximum of 20 seconds once the beans have been ground before creating their coffee for judging. ( if you enjoy watching paint dry, these championships are for you ).
Anyway, back to reality, there are lots of domestic grinders to choose from.
The first type are the ‘knife’ type, sometimes sold as spice grinders. The attraction is that they are very cheap (from around £5 upwards). A dedicated coffee grinder type will purposely only have a small capacity, and usually have a pulse type switch, to avoid overgrinding. Apart from their price, other advantages are that they are quick, easy to clean and don’t take up much room on the worksurface. Their disadvantages are that you don't really have much control on how fine or coarse the ground coffee turns out. This is important because if you overgrind the beans you will have lots of sludge in the bottom of your cup, whereas under grinding will result in a ‘thin’ coffee with little taste. The major disadvantage in my view is that they always heat the grinds up as the blades whizz through the same beans time and time again. This is bad because it drives off the lovely aromatic bits of the coffee. (you want the flavour in the cup rather than in your nose!).
The next level, admittedly at a higher price, are burr type grinders. These work along the lines of a small millwheel. There are two horizontal grinding discs, facing each other and the beans feed in from the centre. As they spin towards the outside they are ground by the wheels and collected in a hopper beneath. They have the advantage of being able to grind different particle sizes so you can tailor the right size for your brewing method. At least three manufacturers offer an entry level burr grinder at around £40. These are Delonghi, Krups and Klarstein. They all boast variable grind settings, but in my experience ( I have actually bought several of each of them ) whilst they all grind a size which is perfect for a cafetiere, they may, or may not, be able to grind fine enough for an espresso machine. Filter coffee is between the two and is almost always achievable too. There is generally nothing wrong with their longevity, for instance I used a Delonghi.for five years commercially for decaf beans, it was one of the ones that did achieve the espresso grind of course. They also differ with some of the internal materials, and size of motor, but they all work well, and you should be pleased with whichever choice you make. If you have preferences as to where they are made, both Delonghi and Krups are from the far east, whilst the Klarstein is actually made in Germany.
So, an excellent choice and not too expensive.
Up one level to a higher spec of grinder will cost around £70. There is lots more choice at this level, and probably the highest number of domestic grinders are in this bracket. Most of them work on the same principle of two grinding wheels, one stationary, the other spinning. Apart from the higher price, they will also take a larger space on your worktop. They do offer stronger motors and a ‘quicker’ grind. There is a holy grail of achieving ground coffee by not heating the beans in the process. Two main schools are either 1: a faster spin, so although more heat is generated, the process takes a shorter time thus not heating the beans. Or 2; a more powerful motor to grind slowly, thus not generating too much heat in the first place. As far as producing a fine enough grind for espresso is concerned, these are almost certain to perform well, but there may be a few rogues amongst them. At this level, if they don’t, I would return them.
As if it weren’t confusing enough, there is a third type of grinder which emerges at this level, and competes with flat burrs right up to full professional level (£2,000 ish). These are called conical burrs. Imagine a funnel with a cone shaped grinder inside it. The beans fall into the funnel and get progressively cut and cut again until the are small enough to fall out of the bottom of the funnel. Mechanically it needs less power because the motor doesn't have to drive a flat wheel round, so can run faster. The beans are actually ground more slowly and therefore don’t overheat. So goes the argument. I do have experience of the Dualit version, and I am very pleased with it as one of its main benefits is that it is easy to clean out. I bought it (well another five of them actually). I use it commercially in the coffee pod for decaf beans, and also in the roastery for grinding small amounts of different coffees for tasting sessions. It does have a few drawbacks in that it has to be empty before removing the hopper or all the beans will fall out, and it is easy to change the grind size without meaning to! I have read the reviews on it and they do have a few people saying it can’t achieve an espresso grind, but the five I have bought show no signs. As above, at this price I think I would send it back if it didn’t!
From here on up, you are in high end domestic and borderline commercial. At this level (£150 and above) you are more likely to have done your research and are probably very knowledgeable on the subject anyway. You would also expect good design and performance thrown in for good measure.
Summing up, for a domestic grinder there are three different types, all with their pluses and minuses and price levels. I hope this has helped inform your choice, but remember the most important thing, and the reason why you should grind your own beans, only use the hopper to catch the beans, not to keep them for later! In other words, only grind just enough beans for immediate use. If I have any ground coffee hanging about for more than an hour in a hopper I throw it out, but then it is my reputation at stake!
Bean to Cup Machines
- Tips to help you choose the right machine for you!
If you are after that Barista quality coffee in the comfort of your own home, a bean to cup machine is a good option for you. The size and quality does vary but most machines are large (so make sure you have the space before you commit), and generally speaking, you'll get what you pay for!
A good quality machine will usually cost you around £400 - £500 but you can pay up to £1,500 (and more).
However, with some of the deals around this weekend (Black Fri / Cyber Mon), you can get some really good discounts at many of the high street brands (e.g. JLP have £200 off a De'Longhi machine). So below is some information to help you choose the right bean to cup machine (at the right price), for you....
Manufacturers vary, there are several traditional names available, and they bring an added value of trustworthiness, but there are some new names coming along who use quality parts and high levels of sophistication and style so don't be hasty in writing them off.
Software in machines is great nowadays, giving you lots of control and choice for your drinks, but bear in mind that physically the inbuilt grinder actually does the hard work of grinding the beans, and this is where it pays to make sure it is up to the job!
One of the main considerations is the output capacity. There is no doubt that all machines will make a super coffee once you get the hang of it, but the smaller/cheaper machines may struggle if you need to prepare more than a couple of drinks in succession. My first domestic machine (very very cheap) would only make one drink, and then you had to wait for five minutes for the second! Needless to say it was confined to the bin after about 6 months! At the other extreme, the espresso machines we use in our takeaway environment are capable of 100 coffees per hour flat out, but then they cost over £3000 each!
It is important to make sure that you choose a machine capable of producing the number of drinks you need within a reasonable time. It is worth asking the question before, to avoid disappointment later.
All domestic machines will run from a normal household electrical socket, you just need to make sure you have one near to your machine.
Extraction pressure is sometimes used as a selling point and it can be tricky to understand what you need. Essentially, very hot water ( around 94c ) is forced through the ground coffee at around 8-9 bar. Car tyres are roughly 2 bar, so that is some idea. Higher pressures are sometimes claimed, but don't mean much to me. (Pressure and grind particle size is a subject hotly debated in the coffee world, but essentially we probably need to get out more). In case you are worried about high pressure hot water in your kitchen, the way it works is that the high pressure comes from the cold water, which is then mixed with the (low pressure) hot water. So, no worries that the hot water tank will explode!
As you climb up the price range, you can expect more sophistication: inbuilt water tanks may give way to being plumbed in, powdered or fresh milk may be an option together with a milk cooler etc. etc. at each point it is worth weighing up whether the extra installation/ cleaning / maintaining is worth doing for the use it will be at home. it is easy to get carried away with the choices available, but better to pay a little more for quality, rather than features which you will not need.
Now what do i do? - Research!! Look at all the deals you can and find the best price on the machine you like. Some retailers have good comparison functions on their sites so make full use of these and look carefully at the specifications of the machine for the price. Make your decision and don't forget to come back to us for your fresh roasted beans!!!