How to Dial in Grinder

We know what material we need from this page.

We assume that everything is connected and working, machine heated up and grinder loaded with beans.

Lets do this:

First we start with grinding coffee. The grinding part is probably the most difficult to understand and causes most frustration in the beginning. It takes some time and understanding why the bottomless portafilter sprays everywhere but not into your cup for the first 20+ shots. Dialing in they call it.

The amount (grams) of coffee we need depends on our basket size. For a standard 58mm double basket it is safe to use 18g. If your machine has a 51mm basket it will be less. Check for suggestions from your coffee machine supplier.

Whatever the suggested amount is, we keep it constant for now. In our case 18g.

Why we keep it constant? Because we have our other variable: grind size. If we change both at the same time we do not know what had the desired effect. (we also have tamp force, see below)

What is the desired effect? We want our espresso shot in roughly 30 seconds for a double espresso. That is 60ml of espresso usually. For myself, the 60ml is a lot of espresso and I tend to aim for a little bit less. But this is the game you play after you know how to achieve all of this. Brew ratio it is called, but we skip this for now and we are happy to be somewhere between 40 and 60ml. 

As we grind the first time we just start the grinder and see what is coming out. It should be powdery, less fine than granulated sugar. It will take between 6 seconds and 15 seconds depending on your grinder. Smaller burr grinder more towards 15s, commercial size 6s.

As a rough guide, it should fit into our filter basket. If the basket is only half full, too fine. If it does not fit in, too coarse. This process can take 1 kg of coffee just to get used to the grinding adjustment. To make it even more frustrating, most grinders keep some of the previously ground coffee in the chamber, so you see your new adjustment at least one shot delayed. The other issue worth mentioning early, is that you should adjust finer only when the grinder is running. Or at least only make small adjustments between grinding. If not, your grinder can jam due to crushed coffee between top and bottom burr and it can not turn anymore. If this happens, go coarser and then try again.

If we feel the 18g fit into our basket, we tamp it. Tamp it straight without excessive force. They say 10-15kg. Lean onto a weight scale to know how much it is. Much more important than the actual force is consistency. Because tamp force acts as another variable for our coffee shot. We keep it always the same at first. We can play around in 4 weeks.

We have now 18g of coffee, tamped with our chosen force and our grind setting.

Lets pull our first shot. Depending on the machine you pull up the lever or press a button.

If you are (very) lucky you do not see anything for the first 5-10 seconds. Then the first drips and then the cup now filling until we have 60ml in 30s. This is how the shot should look like. Most likely you will be too fast or too slow. 

Shot too slow? If it takes much longer or there is nothing coming out at all you have to adjust your grinder to a coarser setting. It is very difficult to say how much. It can be 10 turns on one grinder or 1/10th turn on another. You can only try again and remember: Keep grams in your basket and tamper force the same.

Shot too fast? If the coffee is just rushing out and filling your cup in 5 seconds you have to adjust for a finer grind setting. Remember do not go too fine without grinding in between. Also remember: Keep grams in your basket and tamper force the same.

This sounds very simple, but in reality for the first time it can take many many shots and shockingly much coffee to find the right adjustment. Do not start with less that 1kg of the same coffee.

(As a little reminder, your knock box is most likely full by now and you could have scraped it straight into your rubbish bin with our Portafiter Scraper)

Because most grinders retain some of the old coffee in the chamber and chute. It takes 2 shots to see the if the changes worked. I suggest still pulling the shots to practice your tamping and workflow. If you want you can keep the shots to practice latte art or use for your next iced coffee. I strongly discourage you from drinking every shot.

This is basically it. You might have to adjust with every bag of new beans or even with bigger temperature drops. But usually it will be quite consistent and only small adjustments necessary. I mentioned the retention of ground coffee in the chute and chamber of your grinder. This will dry out until next morning and result in a (much) faster first shot. You can either dispense some seconds worth of coffee before you make your first shot or just live with it. I have the single shot setting on my grinder with 0.1 seconds longer to accommodate for it. I have never seen somebody using the single shot button to grind single shots. If you seriously wanted to use single shot you probably need a different grind setting. Which is fine, you just can not really change from single to double. So that is what I use the single button for.

Use a WDT tool for more consistency, funnels make it little bit cleaner, use fresh coffee beans. The bean part is actually quite important. Old beans (more than 6 month after roast date) tend do run much faster without crema. I this is your issue, think about getting some good fresh beans.