How to Commission Your Destoner

Estimated Time	Up to 30 minutes
Difficulty	Easy
Tools Required	Between 5-10kg of coffee, a small handful of test stones and debris, a container or tray to inspect what you collect, and (optionally) a small wrench

Watch the video

Prefer to follow along? Watch the full walkthrough below, then use the written steps as your reference.

What the destoner does

The destoner is the part of your lift system that separates unwanted bits — small stones, pebbles, pieces of metal, and other debris — from your coffee beans as they travel through. Good beans keep moving through to your next piece of equipment, while heavier or stray items drop out and collect in a tray at the bottom.

Commissioning simply means setting it up and adjusting it so it catches the bad stuff without holding back too many good beans. You only have to do this once during setup, though you may want to make small tweaks later if you change the type of coffee you run.

Before you start

Make sure your lift is fully connected and that coffee actually moves through it. With everything switched on and the front gate fully open, run some coffee through and confirm it is being carried up and into your next piece of equipment. If coffee is moving smoothly, you are ready to commission the destoner.

You will also want a small collection of test items to run through. The best test pieces are real stones and bits you have pulled out of coffee yourself in the past, because they match what your machine will actually face. Aim for around eight items of different sizes and weights. It is also worth adding a few odd items that sometimes end up in coffee by mistake, such as a small washer, a stray nut, or an unroasted bean, so you can see how the destoner handles them.

A quick tip on test coffee: Use coffee you do not plan to sell. You will run it through the machine several times during setup, and repeated trips can chip and break the beans.

Step 1: Run a first test with no changes

Start with the front gate fully open and make no adjustments at all. Drop your eight test items in along with some coffee and run a full cycle. The point of this first run is simply to see how the machine performs out of the box before you change anything.

Step 2: Check what you caught

There are two places to look:

The magnet tray. This holds magnets that grab anything containing iron, such as a stray washer or nail. When you lift the tray out, give it a look from the bottom too — a heavier stone stuck to a magnet can slide around to the underside, so check both faces.
The stone catch tray. Slide this out from the bottom and tip the contents onto a table so you can see exactly what was collected.

While you are there, notice how much coffee is sitting in the catch tray. A lot of leftover coffee means too many good beans are being thrown out, and that is something you will reduce as you adjust the machine. On a first run with no changes, it is normal to catch only some of your test items and to have a fair amount of coffee left over.

Step 3: Adjust the front gate (the bean gate)

The front gate is a sliding panel that controls how fast and how many beans enter the chamber. Lowering it slows the beans down and lets them settle gently onto the tray rather than rushing in and bouncing around. This gives the destoner a better chance to separate the heavy debris from the lighter beans.

Use the two dials either side of the destoner and slide the gate down to about halfway and run another test. Keep lowering it a little at a time until you find the lowest position where coffee still flows steadily without stopping. That sweet spot is as low as it will go without stalling. This where you want the gate.

Step 4: Use the viewing window to judge speed

Your destoner has a clear window (sometimes on the front, sometimes on the side) that lets you watch the beans as they rise. Look for a slow, steady, gentle upward flow — almost like a waterfall in reverse.

Compare the speed in the window to the speed of the beans higher up in the system. If the beans in the window are moving about as fast as everywhere else, they are moving too quickly, and you should lower the front gate further. A slower, calmer flow in the window means the destoner has time to do its job.

Step 5: Adjust the air riser

Once the gate is dialed in and you are catching most of your test items with little coffee left over, you can fine-tune the airflow using the air riser. This is a sliding piece at the front of the machine.

To adjust it, loosen the nuts at the top just enough that the piece can move but still has a little grip, then loosen the finger screw. You can now slide the riser up to line up with rows of small holes. Opening more holes increases the airflow, which makes the lower part of the chamber lighter and "airier." Good beans still get carried up, while anything heavier tends to stay down and drop out.

Open the airflow half a row of holes at a time, and run a test after each change. Keep going as long as your results keep improving. The moment your results get worse — fewer stones caught, or more good beans thrown out — you have gone one step too far, so move back to the previous setting.

Step 6: Repeat until it is dialed in

Setting up a destoner is a back-and-forth process. Run a test, check both trays, make one small adjustment, and run again. With each round you should see more debris caught and less good coffee left behind. The two tend to go together, the fewer beans you lose, the cleaner your debris collection will be too.

Knowing when it is right

A well-set destoner should catch all of your test stones and debris while leaving fewer than ten coffee beans behind in the catch tray. Once you reach that point, your destoner is commissioned and ready for everyday use.

A note on different coffees

Different coffees behave differently in the machine. A dark roast, a light roast, a high-altitude bean, a low-altitude bean, or an unusually large variety can each call for a slightly different gate or airflow setting. If you switch to a noticeably different coffee and start seeing debris slip through, simply revisit the front gate and air riser and make a small adjustment to suit the new beans.

Troubleshooting

Problem	Likely Cause	What to Try
Too many good beans left in the catch tray	Beans are entering too fast, or there is too much airflow	Lower the front gate a little, or close the air riser by half a row of holes at a time until fewer beans drop out
Stones or debris slipping through with the coffee	Beans are moving too quickly for the destoner to separate them, or there is not enough airflow	Lower the front gate to slow the flow; if that is not enough, open the air riser half a row at a time
Beans in the viewing window move as fast as the rest of the system	The flow is too quick for proper separation	Lower the front gate until the window shows a slow, steady, gentle rise
Coffee stops flowing or stalls	The front gate is set too low	Raise the front gate slightly until coffee flows steadily again
Results got worse after your last airflow change	The air riser is open too far	Move the air riser back to the previous setting — the step before things worsened is your sweet spot
Metal bits not being caught	Item may not contain iron (for example, stainless steel)	These pass through by design; the magnets only catch iron-containing metal. Confirm by checking both faces of the magnet tray
Switched coffee and debris now slips through	Different roast, size, or density needs a different setting	Re-check the front gate and air riser and make a small adjustment to suit the new beans

Good to know: why the lift pauses between cycles

You may notice the lift works in cycles rather than running constantly. This is normal. To pull coffee up the tube, the system seals itself and uses suction, which means it cannot release the coffee at the same time. So it fills up, pauses to drop the collected coffee into your next piece of equipment, then seals again and resumes lifting. These regular pauses are part of how the system is designed to work.