7 tips for dialling in an espresso blend

These tips probably apply more to a commercial environment than a domestic one, but hopefully there are some useful reminders for anyone in here.

We’ve all ended up chasing an espresso, somehow a delicious espresso remaining elusive.  These may seem obvious but all get overlooked from time to time.

1. Plan for palate fatigue

Palate fatigue is inevitable, and too much coffee doesn’t just change and dampen your ability to discern flavours – it also quickly affects your enjoyment of coffee too.  David Schomer made a very good point once – coffee never tastes better than when your body really wants it.  We can often be a lot more forgiving of flaws when drinking that first cup that we really want.  The opposite is true for me also.  After too much coffee nothing tastes good.  When my body has had enough caffeine an espresso may be technically correct but I won’t find it delicious.  At this point continued tasting is not particularly useful.

Scott Rao recommends not just spitting the espresso you taste, but also rinsing immediately afterwards with water.  This is pretty much the best way I’ve found.  Drinking less coffee slows my caffeine ingestion, and the rinsing slows general palate fatigue.

2. Don’t overreact

Frustration dialing in a grinder often leads people to react too quickly to a bad shot.  Making sure that you’ve isolated the problem before making a change is very important.   All too often a shot will run fast and a barista will immediately change the grind a little finer.  The next shot runs too slow.  Double check before making a change, because everyone makes mistakes – an accidental underdose for example.

3. Purge

Even the best grinder in the world retains quite a lot of ground coffee.  Most visibly in the throat between the burrs and the dosing chamber, but also in the dosing chamber as well.  Every grinder benefits from a decent purge – 10g to 15g is plenty.  Consider it an investment in the next shot, rather than a waste.  Ending up with a dose made up from a mixture of grind settings is not a good thing.

4. Taste tells you everything

It won’t always point to the problem, but the balance of the espresso will give you a pretty good idea of what is wrong.  Unbalanced, dominant acidity coupled with astringency points towards underextraction.  It could be a number of reasons – pour too fast, temp too low, shot volume too short – but you can be pretty confident that you haven’t taken enough from the coffee.  An excessive, dominant bitterness and an unpleasant finish will usually point to overextraction.

5.  Take a broad sampling

When you are dialling in things like brew temperature this is incredibly difficult to do from only a few espressos.  Tasting more will allow you to get a better idea of what is wrong.  Little mistakes made from shot to shot can easily obscure bigger problems.  I don’t feel confident about saying a brew temperature is wrong until I’ve experimented with a number of other things first.

6. Have a strategy

Be methodical when working with an espresso blend.  Keep in mind that there are a number of different variables that we can change and work through.  Brew time, dose, grind size, brew temperature and shot length are the ones we would typically play with – though pressure is steadily gaining more attention (though I’ve yet to see any conclusive advice on using pressure to improve a shot.)

That said – feel free to abandon dead ends.  If you start with a 20g dose and no matter what you do it tastes underextracted/sour then increasing the dose is unlikely to fix that particular problem, so pulling shots at 22g or 24g may just be mean to your palate, rather than being a good way to use the coffee that you have.

7. Keep it clean

A dirty machine isn’t going to make good coffee.  It seems obvious but dirt builds up incredibly quickly in any espresso machine and it doesn’t take much build up before everything starts to taste disappointing.  Portafitlers, screens and blocks should be cleaned regularly and don’t be afraid of using chemical to clean often.  A coffee machine can’t be too clean!

19 Comments

  1. Thanks for that. I am preparing for my first ever dialing in soon (provided that I actually get the job that where I was tested on Friday)…
    One thing that makes me curious and I haven’t read about it much is the reliability of dosing on a grinder. It’s clear, that the dosing is based on volume, not weight. I suppose that the volume, and thus the mass can change a bit when I tweak the grinding, and I am not sure how consistent it generally is. So should I whip out a digital scale at least while dialing in, to make sure that my dosing is under control?

  2. I find that I usually need to purge a bit more than 10-14g. On a Mazzer Robur E I run two double doses after tweaking the grind. If you sometimes use grindz to clean your grinder there will be plenty of residue of the grindz tablets after several shots. I take this as a hint that the same will be true of the previous setting on your grinder when you change to a finer or coarser grind.

  3. How important is the structure of the puck to the striving towards the perfect shot? If the temperature and pressure is right and the taste is on the spot, do you obsess over a soaky and wet puck?

  4. There isn’t a great deal of value in post brew puck analysis – in my opinion. The wetness/dryness of the cake is mostly down to the size of the dose. A high dose has little room for expansion when you stop brewing and the solenoid releases the pressure from the group head – so it remains a solid puck. A lower dose has a lot more room to expand and therefore ends up a much wetter, softer coffee puck.

    There are, of course, other factors that can affect this – but dose is the main one. Therefore as long as the condition of the puck matches my expectations for that dose then I don’t worry at all.

  5. I used to think brew recipes would solve everything. I find however that often they don’t result in the advertised shots…especially when they’re produced using different water i.e. London water v Scottish water. I also find that people often experiment less when they have a brew recipe they can jump on.

    I would rather start with information on target shot character i.e. desirable level of acidity, body, flavours. With this information I generally find the shot the roaster intended faster.

  6. Hello everyone,
    I was wondering what your thoughts were on the ever increasingly popular grind on demand grinders. My experience so far is that a small adjustment in the grind has a large affect on the dose and a small adjustment on the grind time has a small affect on the dose. This appears to be accentuated in new grinders or with a new set of blades.
    Dialling in these grinders simply takes a bit longer as you are continually adjusting the grind time to compensate for a grind adjustment. This is where the issues begin, the on-going grind adjusting. These grinders are sold at a premium with the benefits of consistent dosing and fresh coffee but the second you adjust the grind the dosing goes out the window, with negative results, for example; if you have a good dose and a fast extraction you would adjust the grind finer. Making the grind finer will decrease the dose which will increase the extraction leading the barista to adjust the grind finer again you can see how this shot is on a downward spiral. Perhaps the micro adjustments to the extraction time during the day should be carried out by adjusting the dose with the accurate timers on these grinders….your thoughts here would be appreciated.
    Cafe owners invest in this equipment to improve consistency in their espresso, perhaps they are not quite as easy to use and adjust as they appear on the surface……

  7. Glad you mention Rao, who seems to be the only person talking about using finer grind, lower dose to adjust the profile of the shot. With the trend toward triples and massive doses I think the elegance and sensitivity to this “less is more” approach is lost. Also, a quick note on pucks–the aroma inside a freshly spent puck is telling about the quality of the coffee and the roast. Would be interesting to study and quantify coffee post-shot by way of the puck sniff test. If you have several different roasters blends in front of you, break them in half and sniff the inside. Not sure the value of this but it is interesting to note the pleasing aromas in some vs others.

  8. Hi guys,

    good post James and good point about the taste, in the end that’s the main goal (then again if it all goes terribly wrong look-wise, you can’t really hope for a nice taste, can you? something I’ve experianced for the last few months).

    Few things about grind-on-demand grinders:

    – change in grind setting will take a while to ‘kick-in’ so pull a few shots before you actually make further changes or as James pointed above purge for a few seconds before pulling a shot at a new setting

    – on timer-fitted grinders it’s usually easier to change the dose than change the grind setting, especially when fine-tweaking

    Regards,
    dsc.

  9. James,

    Thanks for your coffee wisdom. Could you speak a bit more on “Purging” the grinder? Steps? Technique? Etc.?

    Cheers,
    Nathan

  10. Great post, you’ve provide some very useful tips for improving the flavor of coffee in an office environment.

  11. Thanks for this and many of the posts on this blog. It’s good to hear from other coffee lovers & find fellow coffee advocates blogging about it.

  12. Could someone please point me to the section in Rao’s book where he discusses underdosing?

  13. Anthony –

    Are looking for a specific page number? I have Kurt’s copy held hostage, so I will have to be the one to help you =]

    What I saw was on page 30: “Espresso-Making Techniques in Italy Versus America”

    Let me know if that is what you’re looking for!

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