#dialling in

[astralportalmultidimensional]

Dialling in -.. .. .- .-..

[repackespresso]

Milk - The Overlooked Factor - Part 3

Before I start, I should probably preempt any groaning by promising that this is my last post about milk (at least for the time being...)

In my previous article I discussed my intention to test how espresso pulled three different ways - ristretto, cut short and run the same as straight espresso - produced different results in milk. The idea was to reach a conclusion on whether we should be treating milk drinks, which make up the majority of sales, differently to pure espresso shots.

Unfortunately, my experiment didn’t result in much usable data. The first problem was that, even with the shot pulled 30% shorter, the taste of the 4oz milk drink was barely affected. It took a drop to 16g in/20g out before the shorter shots tasted identifiably different in blind tests.

Once we’d changed the brew ratio to reflect this, we started again. This led to the second issue, which was that there was no clear preference amongst those in the sample group. The only constant was a preference for the normal shot or the ristretto, with few liking the standard shot stopped short.

Although we didn’t measure extraction yields, I strongly suspect that the latter had the lowest extraction, which suggests that there is a point at which under extraction, which can allow a subtle espresso to better cut through milk, imparts a negative flavour on the beverage.

Interestingly, the milk drink that was most often picked as the sweetest was the one made with a standard espresso. Traditionally ristrettos have been regarded as the sweetest espressos, as the sugars are extracted early in the brewing process, and are, therefore, proportionally higher when the espresso is shorter, as the sugar to liquid ratio is higher. However, more recently a link between higher extraction yields and sweetness has been noticed, which may help to explain why the piccolo with the longer, more fully extracted shot was regarded as the sweetest.

Of course, the sample group for this experiment was fairly small, and we only used one type of  bean; it is perfectly possible that different beans would yield a more conclusive result.

For now, though, I will be pulling my milk based drinks at the same brew ratio as straight espresso, as my personal feeling is that these tasted best in the experiment. I am, however, open to change if the evidence points me in a different direction in future.

[repackespresso]

Dialling In

A while ago I promised to post an article on dialling in. Unfortunately, I ended up being slightly side-tracked with other subjects, but I did produce a piece for the Perfect Daily Grind website covering the topic.

Rather than duplicate it here, I thought I’d just post the link. So, here it is:

http://www.perfectdailygrind.com/2015/07/5-barista-certified-rules-for-dialing-in-your-coffee-grinder/

[repackespresso]

Dosing Down - How Less is More

It’s quite easy to forget how young speciality coffee in the UK is; it seems like a lifetime since I first walked into the original Colonna and Smalls, tucked away behind Bath’s Theatre Royal, but, in reality, it’s barely more than five years. London had speciality coffee as we know it today a little earlier than that, but it’s only in the last five years that it has become widespread in the capital.

In that time there have been huge changes in the industry: pressure profiling, the EK43 as an espresso grinder, and the über boiler being just a few of the equipment-related innovations.

At times it has felt like something of an arms race - I’ve lost count of the number of prospective coffee shop owners I’ve met who’ve talked about the necessity of running an EK43, as if they can’t be taken seriously without a hulking great copper-coloured grinder sitting on the counter.

The interesting thing, though, is that, whilst many aspects of speciality coffee have changed greatly in the last few years, commonly used doses and outputs of espresso have, with a few exceptions, stubbornly refused to shift.

OK, so the pre-2010 speciality staple of the 20g+ dose triple shot is less ubiquitous than it was, but I still see many roasters providing brew recipes with 20g doses and 30g outputs.

You might wonder what is wrong with this; doesn’t this sort of brew ratio and dose produce a sweet, tasty espresso, after all? The answer is, yes, it can, depending on the coffee itself, and sometimes it’s a necessity (more on this later), but there is so much more potential in running a longer, lower dosed shot with a higher extraction yield.

At this point it’s worth looking at the history of speciality coffee, and how the traditional 14g double dose of Italian style espresso became the 21g triple ristretto. Scott Rao in The Professional Barista’s Handbook points to the need to make shots cut through the relatively large milk drinks (in comparison with the typical 5oz Italian Cappuccino) common at the time as the main reason behind the updosing, and I’m iclined to agree with him. The ristretto element came as a result of maintaining the same wet dose.

The problem with this was that it tended to result in under extraction, and acidic tasting coffees - something which speciality coffee detractors often used as a criticism of the industry. This in turn led to the search for naturally sweeter coffees and a continual spiral of under extraction, albeit slightly better tasting under extraction.

All of this wasn’t helped too much by the presence of the Mazzer Robur in many high volume shops. The Robur’s party tricks are a fast grind and conical burrs that are less prone to grind size changes when hot than many of its competitors. Unfortunately, for reasons that are not entirely clear, but probably relate to grind size distribution, it struggles to produce espresso that has an extraction yield above 20% and still tastes good.

As roasts became lighter, and consequently harder to extract, doses gradually moved slightly lower, with 18-19g being a commonly quoted figure amongst roasters and coffee shops in recent years. However, brew ratios remained, in many places, at the 60%+ mark.

Many coffees taste OK, or even quite good at this level; the acidity from slight under extraction being masked by the sweetness that comes from running the shot short, in much the same way that an acidic tasting apple, for instance, can be enjoyable if the sugar levels are also high. The higher tds that this brew strength provides also gives the typical espresso mouthfeel that many coffee drinkers like. With some conical grinders, also, this is the only way to produce a tasty espresso.

But it does beg the question of what we are looking for in speciality coffee: a short, sweet shot with a single intense flavour, or something a little more complex?

My entry into coffee was unusual in that I never really drank pre-speciality coffee; I just didn’t drink coffee at all ten years ago, and was far more interested in fine wine - especially cru classé Clarets and amazing Pinot Noirs from Napa and Burgundy that I couldn’t really afford. This has led me to search, very much for the latter type of espresso - one that can mirror, or even exceed, the complexity and elegance of a great wine. Short, sweet shots, to me, are akin to the lesser of the new world wines, where up front fruitiness and sweetness is displayed at the expense of more complex characteristics and ageworthiness.

Achieving this complexity is largely down to the quality of beans and roast, equipment, grind, dose and output. The beans and equipment I’ll leave for another post, but it’s worth noting that we use large flat burr grinders, trusted speciality roasters and almost entirely single origin/estate beans.

Which leaves us with grind, dose and output, which are the main variables, together with time, that a barista manipulates when dialling in a coffee. 

Starting with output, the size of an espresso cup is such that anything over 45g is going to be too large, so our range of possible outputs is from a very ristretto (even with a small basket) 20g to a somewhat out of proportion 45g. The most appropriate size, in my view, is between 28g and 35g, which sits well in the cup and conforms to the general expectation of espresso size. If we work backwards from this point we can see, however, that we are limited, with the commonly used 18g basket, to a maximum brew ratio of around 50%, even if we drop the dose to 17g. A 20g basket would be even worse, resulting in a ristretto shot and likely under extraction.

The answer comes in the form of a return to the smaller baskets common in traditional Italian coffee shops. A 15g VST basket gives us the ability to run quite long shots with low brew ratios without exceeding the 35g mark. Because the geometry and hole diameter on VST baskets are proportional to their size, in theory,an 18g dose in an 18g basket at a 50% brew ratio should produce a very similar espresso to a 15g dose in a 15g basket at the same ratio. In practice, however, we’ve found that the smaller basket requires a grind one notch finer on the Super Caimano to retain the same flow rate and flavour.

There are a couple of issues with using smaller baskets. First, the lower dose absorbs less heat, so it is possible that over extraction may occur. Our Kees Van Der Westen is set to 92C and I have not observed this happening, but it is easily remedied on any PID controlled machine by dropping grouphead temperature by a degree or two. Second, the smaller amount of coffee means that the espresso cuts through less in larger milk drinks. This is not a problem for us - our flat whites are 5ozs and our biggest drinks (lattes) are only 8.5oz, but it may be more of an issue in shops that serve a large number of 12oz plus coffees.

So, we now have a starting range for dose and a range of outputs with which to work, but how do we achieve balance, elegance and complexity in the cup? As I’ve already mentioned, running the shot short emphasises body and sweetness at the expense of complexity, so we’ll eliminate brew ratios above 55%. Brew ratios lower than 40% produce a very low tds drink; this can be delicious, but it becomes something slightly different from espresso and usually isn’t the best tasting length in milk (which, even in a highly focused shop, is where most of the espressos will find themselves).

Some baristas choose a brew ratio within the 40% - 55% range then stick with it as if it’s some sort of holy commandment (’Thou shalt not deviate from a 50% ratio’). This approach does have the advantage of reducing the number of variables in dialling in, but it also limits the potential of the coffee; sometimes running a shot a bit shorter or even significantly longer than 50% can greatly improve it, whilst, in comparison, rigidly adhering to a set recipe results in a small compromise.

My feeling is that brew strength and viscosity are less important than complexity and elegance, so I tend to run shots in the 45% to 50% range, unless I’m presented with a bean that lacks the clarity to do this (usually where over development in the roast has taken place). I want clearly defined, clean flavours, and these seem to happen at the lower tds range.

Our current two espressos are running at the following levels today (I tend to make minor tweaks each day, but no more  than 0.3g to dose and 1g to output, generally):

Round Hill Mpemba (Rwanda)

15g in

31g out

30s

Notes Caffesur (Colombia)

14.5g in

30g out

31s

Both are exhibiting great complexity - the former with tropical fruit flavours that linger with a long finish, the latter with dark chocolate and almond up front complemented by a berry-like after taste.

In the next post we’ll look at equipment and its influence on the drink in your cup.

[celtic-roaster-blog]

Dialling In

We have a barista training session at the Roastery this morning so before everyone arrives it’s time to dial-in the espresso machines and grinders. This involves pulling espresso shots and making changes to the grinder and espresso machine to ensure the coffee we serve is of the correct quality and matches a specific set of parameters.

There are three key parameters we check: the weight of the ground coffee we are going to use, the time it takes for the shot to extract and the weight of the resulting espresso.

This morning I started with an 18.6g dose of ground coffee, and pulled a 29g espresso over about 28 seconds. The 18g dose is determined by the size of the portafilter baskets I was using, the extraction time of 28 seconds is typical for all espresso we make[1], and the end beverage weight relates to the amount of water we pass through the espresso.

Whenever we set about dialling in the espresso, we always use taste as the deciding factor. We look for a bright acidity, good sweetness as the espresso cools, some body and a lingering aftertaste. We also want to be able to pick up some of the flavours in the coffee.

While this process uses up a bit of coffee, and requires a commitment of time, it is often this attention to detail that separates a good coffee shop from a mediocre one.

We have very soft water at our Roastery (sometimes as low as a TDS of 20ppm) and find that extending the extraction time can counteract the impact of this water, particularly when pulling shorter shots.  ↩