Descaling dissolves the mineral crust that hard water leaves inside a boiler, using a citric- or lactic-acid solution run through the machine per the manufacturer's cycle. On tank machines fed hard water, run it every one to three months. On machines fed properly treated water, you may never need it, and on some prosumer machines you shouldn't attempt it at home at all. The decision comes before the instructions.
First: should you descale at all?
| Your machine and water | Descale? |
|---|---|
| Tank machine (Breville, De'Longhi, Gaggia) on hard tap water | Yes, on the manufacturer's cycle, every 1 to 3 months |
| Tank machine on filtered, softened, or recipe water | Rarely; watch the flow and taste, expect intervals of 6 months or longer |
| Prosumer machine (E61, dual boiler) on treated water | Prevention is the plan; descale only when symptoms appear, and read your manual first |
| La Marzocco Home machines and similar saturated-group designs | Not a DIY job. La Marzocco's own guidance is right water in, and service if scale ever takes hold. Loosened scale migrating into valves does more damage than the scale did sitting still. |
The logic: descaling is not maintenance, it's a correction. Scale forms when calcium-heavy water gets hot; the acid that removes it also finds every weak o-ring on the way through, and flakes it dislodges can lodge in gicleurs and valves. Machines that never see scale-forming water never need the correction. That is the whole argument of our water guide, and it's cheaper than one service call.
The signs you're due
Slower flow from the group at your normal grind, a kettle-style white crust on the tank or around fittings, steam pressure that fades, a flow that spits and stutters, or shots that run hotter or cooler than they used to. Any of those on hard water: descale. All of them on treated water: check the grinder and the cleaning schedule first; oil clogs mimic scale clogs.
How to descale a tank machine
- Use a descaler made for espresso machines (citric or lactic acid, $5 to $10 a dose) and mix per its label, typically one packet or 25 g per liter of warm water.
- Fill the tank with the solution, remove any in-tank water filter first, and park a big bowl under the group and wand.
- Run the manufacturer's cycle. Most Brevilles and De'Longhis have one in the manual (often a button combination). No cycle? Pull a third of the tank through the group and wand in 20-second bursts, rest 5 minutes, repeat until the tank is nearly empty, then let it sit 15 minutes with the machine hot.
- Rinse like you mean it. Two full tanks of fresh water through group and wand. Acid left behind attacks brass and gaskets and, less romantically, your next latte.
- Pull a sacrificial shot and dump it, then taste water from the group. Neutral means done.
What not to use: vinegar
The searches say people do it, so, plainly: household vinegar is a weak descaler and a strong mistake. It needs longer contact at higher concentration to match citric acid, its acetic fumes linger in plastic and silicone for dozens of brews, and several manufacturers void coverage over it. A purpose-made descaler costs less than the bag of coffee you'd ruin re-tasting vinegar for a week.
How often, by the numbers
Scale rate follows hardness. On very hard water (above roughly 200 ppm as CaCO3, common across the US Southwest and Midwest), a daily-use tank machine can lay down visible scale in six weeks. At 50 to 100 ppm, quarterly is plenty. Below that, or on remineralized RO and recipe water with near-zero calcium, there is nothing to descale: the crust never forms. Test strips cost a few dollars and end the guessing; your city's water report is free and lists hardness by zip code.
That's also the answer to "how often should I descale a Breville": the honest interval is set by your faucet, not the calendar. Hard water, every 60 to 90 days with the machine's cycle. Treated water, when symptoms say so.
The Small Hours position
We'd rather sell you nothing than sell you descaler forever. Fix the water once: a $30 test kit and a jug routine, or a filter matched to your hardness, and descaling drops out of your life for tank and prosumer machines alike. Our bar's Linea Mini has never been descaled and, on our water, never should be. We don't sell La Marzocco machines or descaler as of this writing, so take that as testimony rather than a pitch, and read it skeptically anyway.
Sources worth your time
La Marzocco Home's care guidance · espressoaf's water guide · Your machine's manual, which outranks every blog including this one