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Dialling in the E Grinder

Five Senses CoffeeAndrew Easthope 9 September 2014

Using an E grinder in a café or at home is a smart idea. When it’s paired with a good set of scales, your espresso setup can transform your coffee brewing experience and push you further towards creating consistently excellent results. Here’s a quick ?how to? guide to setting up an E grinder using a new coffee, maintaining good results and, ultimately, keeping your grinder in top notch shape for a long time. Every grinder is a little different; for this how-to guide, we’ll be focusing on the Mazzer E grinders.

Get good results quickly

So you’ve just picked up a new coffee and are eager to set up your grinder. Here’s the best way to tackle it:

Clean
Your grinder should be clean and as free from any leftover coffee as possible — if you remove your hopper and place a plunger on top of your grind collar, you’ll get enough of a seal to flush out the internal chamber. Take off the E-pad and have a look at the grill — a truly clean grinder has no excess coffee visible in the chute. Using a dry cloth, wipe down the inside of the conical dispenser. This often gets a build up of super-fine particles over time and needs to be cleaned on a regular basis.

Season
To get some consistent results and start making adjustments, the chamber inside your grinder needs to fill up and your grinder needs to have been operational. Compared to a warm grinder, a cold grinder produces some startlingly different results, so before testing, it’s a good idea to produce four shots of espresso from the grinder to get things rolling. It’s not a good idea to rely on your auto-dispensing buttons, so instead manually dose until you achieve your target dose weight. There’s more to come on that below.

Testing time
So you’ve arrived at espresso extraction number five; here’s where we start to test our settings. You?ll need a set of scales for this guide. We?ll be standardising our dose and barista technique in order to make accurate grind adjustments and achieve a basic starting recipe.

As an example, we’ll use the recipe that we currently use in training and outline how we achieve these numbers. We?ll talk a little less about why we aim for these numbers because, at the end of the day, a recipe is just a starting point for you to taste, after which you should adjust it based on your own results. Recipes are a helpful starting point though! Here’s our training recipe using 20gr VST baskets on a Synesso:

Dose: 22gr
Beverage: 36-38gr
Time: 28-32 seconds

Across our blends and most of our singles, this recipe has served us well (but we do tweak them considerably from this point on, depending on the coffee). We alter the dose and beverage weight depending on the machine and the basket used at the time, so keep in mind that you may need to do the same on your personal setup.

Notice how the widest range given is the amount of time? The time it takes to achieve our beverage weight with our chosen dose tells us a bit about the other two main variables at play; your barista technique and your grind setting. If you can keep your barista technique consistent, you’ll remove this as a variable, leaving grind as the only variable in achieving the target time. This, of course, comes with several caveats; we’re not factoring in your barista technique and therefore don’t know whether you’re achieving an even distribution or brew temp etc. We?ll just assume you’re all over it.

Logical steps

For your test, you’ve got to work quickly from your first four espresso shots in order to simulate how your grinder behaves during peak production periods. Going against the intended usage of our E grinder, we’re not going to use the auto-doser right away. If you feel the need, you may use it (although if we make any grind adjustments you’ll find the dose delivery and dose weight will change, meaning you’ll be constantly updating it).

  • In order to make adjustments work for you, you’ll need to standardise two of your recipe parameters to discover how accurate your grind setting currently is. There’s more information about this below.
  • Using the manual grind button, you can achieve your target dose to within -/+0.2 of a gram. Use your scales to check this. This is a range we use to standardise our dose for testing or grind and you may need to add in or remove coffee to do this. Some of our customers don’t grind in the portafilter and instead use a small cup, meaning they can adjust the weight and then tip it straight into their portafilter
  • Prepare your espresso shot as you usually do. We currently train our customers to avoid collapsing or settling, so just distribute the grounds, and apply one even, firm tamp. Whatever you choose to do, keep it the same each time to remove technique as a potential variable.
  • Using your scales (or ideally a second set), tare off a cup so you can weigh your espresso. You?ll want to start your extraction and a timer simultaneously. If you’ve got shot timers then life is easy, otherwise you’ll need to use an external timer.
  • Start your espresso extraction. If you don’t have volumetrics, run your espresso extraction until your chosen target time (in our case, we choose a point between 28-32). The resulting beverage weight is the information we need, as this then tells us how fast or how slow our extraction is pouring, meaning you needn’t rely on the visual appearance of your extractions alone. That’s not to say that it isn’t useful to watch your extractions, but the numbers don’t lie!
  • If you use volumetrics, you’re in luck. You should still weigh your beverage to ensure it’s consistent (and to see whether it needs to be re-programmed), but you can use your programme button as opposed to a manual switch or paddle for your coffee. Your beverage weight should be accurate to within that -+3gr of your target. The crucial information to capture here is how long it takes to achieve your result, as your volumetrics should be taking care of the beverage.

Here’s how to use that information for your grind adjustment. On our training grinders (which are Robur Es which are quite large grinders), we have worked out that by moving our grind collar by one notch, we end up seeing a 4-5 second change in contact time, or a 10gr change in beverage weight.

This would change on smaller grinders, but with a bit of your own testing it will be easy to discover how these numbers change with your own adjustments.

Decision time

At this point, the vast majority of grinders on the market (Mazzers included) hold up to 60gr of ready-ground coffee inside them. In our experience, it takes up to 100gr of coffee to run through the grinder before your grind adjustment catches up due to the way coffee cycles through them.

This means you won’t see your grind adjustment fully kick in for at least three espresso shots, and it will gradually settle after five or so. Keep this in mind! The last thing you want to do is re-adjust based on the next readings you take.

The decision you need to make here is whether you purge the grinder, or make the adjustment and wait it out. From a quality perspective, for large adjustments of 2+ notches it’s worth purging that coffee through. We think it’s an awful waste of coffee though, so wherever you can tweak your adjustment and wait it out, that is the recommended practice.

Analysing your results

If you’ve achieved your target recipe, well done! But remember that this is just a starting point. Achieving some numbers in a recipe is no guarantee that you’ll be getting the absolute best tasting results, but in our experience it’s without a doubt an easy way to achieve good starting results with any coffee. By the same token, once you’ve worked with a particular coffee for a while and get to know it, you’ll start to figure out which numbers do and don’t work.

Once you’ve hit some numbers and tasted your coffee, you may then decide to adjust your time target to achieve a better result. This can be accomplished by adjusting your grind finer or coarser in order to hit your beverage weight target in a different time frame. Two seconds of contact time can make a huge difference to an extraction, so don’t be afraid to make those half or quarter notch adjustments; it’s how you get the best out of your coffee.

Also, don’t be afraid to scrap our recipe and start afresh. We’ve experimented with our coffees and with recipes that move far outside of the above parameters and have still produced some tasty results? keep it interesting and mix it up when you get a chance to experiment.

Automating your results

Achieving a low variance on an auto-grinder is occasionally what you’ll experience in peak production once the grinder is heated. However, it’s more likely that the variance is to the tune of -+0.5gr, sometimes higher, sometimes lower depending on the grinder and grind setting. Grinders which use time to dose (rather than weight), typically provide this sort of variance.

Now you’ve got your recipe dialled in, it can be automated. Simply push one of the automated buttons, catch all the coffee and check how much it weighs. You?ll need to test it, as you’re working to get an idea of how accurate the grinder setting currently is.

If the grinder is accurate, there’s no need to reprogram it! If it’s inaccurate, you’ll need to go in to programming mode, adjust your target time higher or lower and start edging your way towards that +-0.5gr range. The smaller the grinder, the more time you’ll have to change in order to impact the dose weight.

Maintaining your recipe

If you’re in a café, your target grind setting will change throughout the day as the grinder heats up. When you make grind adjustments to counteract this (usually finer), you should also double check that your auto-button is maintaining the target dose weight. Changes to the grind setting affect the dose weights directly due to changing the rate at which the grinding occurs.

Some cafes put their scales away after dialling in; others weigh every shot, both the dose and beverage weights. Once you decide, you have the ability and desire to deliver consistent results; the rest is up to you!