Espresso variables: simplicity vs complexity

Beginner and pro baristas share tips and tricks.
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Postby keno » Jul 31, 2015, 7:28 pm

Based on some recent experience in a few HB threads on the virtues and vices of the Linea Mini (such as this and this), I realized that a pretty sizable group of people on HB think a lot differently than I do when it comes to espresso brewing and equipment choices. As I pointed out the reason I like the Linea Mini is precisely because of its simplicity which, from my perspective, helps to eliminate some variables and thereby make it easier to make consistently good espresso by focusing a lot more on the coffee and preparation - the things a roaster and barista pay attention to.

So to elaborate on that thinking I thought it would be interesting to outline some of the variables that go into espresso making and demonstrate how utterly complex this process is and thus why I, for one, don't want to make it any more complex. Consider the following variables and number of choices/options in parentheses (BTW, I'm sure I'm leaving some things out):

  • Roast (3) - Assuming you roast your own coffee there are of course endless roast profiles, but let's simplify this and assume there is the profile you roasted as well as slightly lighter or darker.
  • Grind (5) - With a top grinder you easily have the ability to tweak the grind to a fairly precise level. With my HG-One for instance I generally find there could be range for a given dose of up to 5 notches. Increase or decrease this as you think appropriate based on the precision of your grinder.
  • Basket (3) - You can probably choose from multiple sizes of basket or types of basket. Let's say you have three to choose from.
  • Dose (5) - For a given basket you can probably dose a range of +/- about 2 grams from the stated dose. Of course you can dose in increments smaller than a gram, so this estimate is conservative.
  • Distribution (3) - The goal here is always to distribute the coffee as uniformly as possible without clumps to reduce channeling. Again, the possibilities are probably limitless, but let's just say there is low (doing nothing), medium (leveling grounds or tapping the PF), and high quality (adding WDT) distribution.
  • Tamp (2) - Generally tamping is believed to not have a huge impact on results so let's just allow for a light or firm tamp.
  • Temp (6) - Temperature is a continuous variable, so there are potentially lots more options here if we allow for greater precision, but let's just assume 1 degree F from 198 to 203.
  • Time (7) - Time is continuous as well, but let's assume a 1 second interval across the SCAA range of 22-28 seconds, though many people would find longer extractions acceptable which increases the options.
Now just using this limited list of options we already have 56,700 possibilities (and this is a conservative estimate). Admittedly, some might not be combinations that we would consider plausible and that will narrow things down somewhat (eg, as you increase dose you would tend to coarsen the grind), but the point is that the complexity explodes because the possibilities increase exponentially with each additional variable. Now let's add in manually controllable preinfusion and pressure profiling.

  • Preinfusion (10) - Assuming from 1 to 10 seconds preinfusion are options with programmable or manual preinfusion.
  • Pressure Profiling (5) - Again the possibilities may be limitless, but the Vesuvius allows users to program 5 options, so let's assume you have 5 respectable profiles.
Now we are suddenly up to 2,835,000 possibilities! It's no surprise to me when I read these forums how often people end up lost in the espresso wilderness and are crying out for help to find their way back to espresso civilization - like this. Sometimes it may be due to an equipment problem and then some changes to things that shouldn't have been changed. Other times it's just a drift off course when switching coffees. But once you get off course it can be notoriously hard to find your way back as the forums and personal experience show.

To have even a remote possibility of effectively controlling all of these variables when making espresso requires at minimum the following: (1) The ability to actually control them. For example, dose can be reliably changed if you have a good digital scale and carefully use it. But some variables are much harder to control, like temperature and distribution. (2) You need to understand espresso theory sufficiently to know what changes you should potentially make and under which circumstances you should make them. And it helps to know how some of these things interact with one another. (3) You need the patience, focus, and determination to actually make the intended changes and monitor them and the results. (4) And, perhaps most importantly, you need a sufficiently sensitive and developed palate to actually detect the differences in the cup. Often people just know that something is off, but can't even say whether it's because the espresso is too bitter or sour. If you can't reliably taste differences and link them with theory, you are walking blind in the espresso wilderness.

If you have ALL of those skills you might have some chance to actually make better espresso with more variables and tools at your disposal (like pressure profiling). And then you better be pulling more than 2 or 3 shots a day. For example, a good third wave cafe has good results because they have a barista operating top-notch equipment, using excellent fresh coffee, AND pulling hundreds of shots a day and continually monitoring and tweaking things. But if you are not operating under similar circumstances you are probably far better off reducing the number of variables and focusing on the few that are known to have a significant impact on the results in the cup and that you have inherent control over or cannot eliminate.

This is why I think the Linea Mini has been such a pleasure to use compared with machines that may have more features but which introduce more variables. I'd rather make great espresso 80% of the time (4 out of 5 cups) than occasionally produce an accidental "god shot" but otherwise be struggling in the espresso wilderness.


Postby brencho » Aug 05, 2015, 2:43 pm

Agreed. I recently moved from a less reliable and less consistent machine with more guess work to a more consistent and reliable machine. Removing variables has suddenly allowed me to really focus on my technique and adjust by taste in a way that I wasn't able to before. Once I find a recipe I like for a bean, I can pull largely identical shots repeatedly, which is also a somewhat new experience. Relatedly, it has allowed me to focus on the coffee in a new way and now I really want to experiment with different beans to find new favorites or rediscover beans I had used before but failed to get good and consistent extractions from. In any case, I'd also advocate for a machine that gets out of the way as much as possible. Increasingly there are a number of machines that allow for this.

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Postby tohenk2 » Aug 13, 2015, 9:25 am

Also agreed. Just with another machine. I am lucky I guess, since I use the Vesuvius, made about 10 shot per day for the one month I own it (there are counters on the Vesuvius and on the Macap MD4) and quite easily hit the 80% very good (and the occasional "god-shot" that kept me smiling and longing for the rest of the day). BTW - my son did not want espresso since he was told it was "stronger" than normal coffee. Eventually he tried espresso and was disappointed at first. He thought "strong" equaled "bitter", and that was by then an acquired taste for him. By now he knows better, but still also enjoys bitter drip coffee from the university.

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Postby canuckcoffeeguy » Aug 13, 2015, 10:27 am

Agreed. The Mini keep things simple.

And if you add the following variables to your list, the combinations grow even higher:

-water quality
-temp profile(HX vs DB)
-grinding burr type(Flat/conical)
-how many days beans are post-roast.

These variables also affect results in the cup.