How to Descale an Espresso Machine

Signs your machine needs descaling

You don't have to wait for the machine to tell you. Watch for these:

• Slower shot flow — a 2 oz shot used to pull in 25 seconds, now takes 40+
• Cooler shots — the espresso comes out lukewarm instead of hot
• Weaker or flatter taste — even fresh beans taste off
• Odd gurgling noises — air bubbles from clogged lines
• Weak steam — the steam wand takes longer to froth milk

How often should you descale?

If your machine has a built-in descale indicator light, follow it — but note it's usually conservative and triggers earlier than necessary.

Step-by-step descaling

1. Prep

Empty the water tank and remove the portafilter and drip tray. Run a blank shot (no coffee) to flush residual water. Have a container under the group head and steam wand to catch the solution.

2. Mix the descaler

Dissolve one packet of Urnex Dezcal in the water tank with warm water. Swirl to fully dissolve. Most home machines use 1 packet per 1 liter of water.

3. Run the brew cycle

Place the tank on the machine. Run the brew button for 10 seconds, pause 30 seconds, repeat. This cycles the descaler through the boiler. Do this 5–6 times. Some machines have a dedicated descale mode — if yours does, use it.

4. Run the steam wand

Open the steam wand valve for 10–15 seconds to push descaler through the steam lines. Close, wait 30 seconds, repeat. Do this 3 times.

5. Let it sit

Turn off the machine and let the descaler sit in the lines for 15–20 minutes. This gives the acid time to dissolve mineral deposits.

6. Flush thoroughly

Empty the tank, rinse it well, and refill with fresh water. Run 2–3 full tanks through the machine (both brew group and steam wand) until there's no chemical smell. This step is critical — leftover descaler will make your next shots taste bad.

Why descaling matters

Water contains minerals (calcium, magnesium) that build up inside your espresso machine's boiler and thermoblock over time. Scale acts like insulation 鈥?it slows heat transfer, makes your machine take longer to warm up, and can cause temperature swings that ruin extraction. On super-automatic machines, clogged scale can block the coffee path and trigger error lights.

How often? Every 2鈥? months for drip machines, every 1鈥? months for pump espresso machines depending on water hardness. If you live in a hard-water area, descale monthly. Use filtered or bottled water (not distilled 鈥?machines need some minerals) to slow buildup.

Step-by-step: descaling a pump espresso machine

1. Empty the drip tray and water reservoir. Remove the portafilter and any basket.

2. Mix descaling solution per the manufacturer's instructions 鈥?usually 1 part solution to 4 parts water. Do not use vinegar; it smells terrible and can damage seals. Use a proper descaler like Dezcal or the manufacturer's branded solution.

3. Pour the solution into the water reservoir. Place a large container under the group head and steam wand.

4. Run the machine: turn it on, let it heat, then run 30 seconds of water through the group head, pause 30 seconds, repeat. Do this 4鈥? times. Then open the steam wand valve for 30 seconds to flush that circuit.

5. Let the machine sit for 10鈥?5 minutes so the solution dissolves scale in the boiler.

6. Empty the reservoir, rinse it thoroughly, and fill with clean fresh water. Run 2鈥? full tanks of clean water through the group head and steam wand to rinse. Taste the last cup 鈥?no soapy or chemical taste should remain.

Super-automatic machines

Super-automatics have a descaling program 鈥?follow the on-screen prompts. The machine will walk you through the cycle automatically. Never interrupt a super-auto descaling cycle; it can leave solution in the internal lines.