How to descale an espresso machine: vinegar, citric acid or what your manual says — and why Cafiza isn't a descaler

To descale an espresso machine, use the descaler your machine’s manual names, run it through the machine’s descale programme — or through the group, the steam wand and the hot-water outlet in turn — and then rinse more than the manual tells you to. Whether that descaler can be vinegar or citric acid is not a matter of taste. The makers have written it down, and they disagree: BUNN tells you to pour a quart of white vinegar into its brewers, Nespresso says vinegar “may cause damage” to its machines, and Philips forbids sulfamic acid, which makes up 10–30% of Breville’s own descaling powder. Cafiza, the third name people search with, is not a descaler at all. It is an alkaline detergent for coffee oil, and it does nothing to scale.

Three findings run under the rest of this piece, and none of the pages that rank for this question gives the evidence for them. Citric acid leaves a calcium salt that dissolves at under a gram per litre of water, against about 300 grams for vinegar’s — one reason the strength of a home-mixed citric solution matters, and Moccamaster accepts measured citric-acid descalers but not citric acid you mix yourself. A seal maker’s compatibility tables rate citric acid satisfactory for all four common seal rubbers and vinegar doubtful for two of them. And Germany’s Federal Institute for Risk Assessment found that some portafilter espresso machines released lead and nickel after descaling, so the rinse is not the formality it looks like.

Below: the two jobs and why one product cannot do both, what each maker tells you to use, what is actually in the bottles, what the chemistry says about vinegar, citric and lactic acid, how to descale each Breville espresso machine, what changes for drip, pod and high-end machines, why the rinse matters, how often to do any of it, and when backflushing helps and when it wears the group out.

Affiliate links. Some links below go to Amazon. If you buy through one I earn a commission at no extra cost to you, and it never changes which product gets named or what the measurements say. Full disclosure.

Two jobs: scale and coffee oil

Most of the confusion in this search comes from treating two problems as one. Products do not help: one descaler on this search is sold as a “Descaler & Cleaner”, and an Amazon reviewer praises a backflush detergent for its descaling.

Scale is what heated water leaves behind. In Philips’ words, when water is heated the calcium and magnesium in it “break down and precipitate to form limescale,” and in the places “where the water sits still for a while, such as the boiler, scale builds up.” It slows the flow, and three makers say in writing that it lowers the brewing temperature — the subject of the piece on coffee makers that run cool.

Coffee oil is a different substance in a different place. Backflush detergents are built for it, and Cafiza is the best known of them. Urnex’s safety data sheet for the powder lists sodium percarbonate at 10–30% and a pH of 11 to 11.5 in a 10% solution: strongly alkaline, which is what lifts oil and the brown residue behind a shower screen. Pushed through a descaling cycle, it would leave scale exactly where it was. One Amazon reviewer, praising it in all sincerity, wrote: “My machine needs descaling quite often. This product works well.” It works well — at the other job.

So a machine needs both, and on different calendars. The rest of this piece is mostly about the acid, with backflushing at the end.

What your machine’s maker tells you to use

The pages that rank for this question argue about vinegar against citric acid as if the answer were the same for every machine. The makers’ own instructions show it is not. These are their words, from their manuals and support pages:

The pattern is consistent. The makers who prescribe vinegar build simple drip brewers. The makers who forbid it build machines with pumps, seals and narrow passages — and Moccamaster, which rules out home-mixed citric acid too. At the top of the price range the question stops being which acid and becomes why the machine scaled in the first place.

Breville is the odd one out, because it contradicts itself. None of the five espresso instruction books I read — for the BES870, BES500, BES878, BES880 and BES920, from the Barista Express to the Dual Boiler — contains the word vinegar; every one lists Breville’s descaling powder among its accessories or in its descale steps. Breville’s own US blog, under a heading about deep cleaning, says: “If using vinegar use 1 part water to 1 part vinegar.” Its sources are a storage company’s blog and a coffee affiliate site. When the blog and the manual disagree, the manual is the document that comes with your warranty.

What is actually in a descaler

None of the ranking pages says what is in the bottle, which is a shame, because the makers publish it. Each descaler has a safety data sheet, and the composition is in section 3:

Two things follow. First, “commercial descaler” does not mean one chemistry: Breville’s is mostly malic and sulfamic acid, De’Longhi’s and Nespresso’s are lactic, Urnex’s are citric with or without sulfamic. Second, the makers contradict each other about one of them. Philips tells Saeco owners never to use a descaler “based on mineral acids such as sulfuric acid, hydrochloric acid and sulfamic acid,” because it “may damage your coffee machine’s pipe and tube system.” Breville puts 10–30% sulfamic acid in its own powder, and Jura, Nivona and Siemens recommend sulfamic-acid products for their machines. Germany’s consumer testers, Stiftung Warentest, found De’Longhi, Krups, Melitta, Philips, Saeco and WMF recommending lactic or citric acid instead, and both they and the consumer advice centre of North Rhine-Westphalia point out that sulfamic acid passes through sewage treatment and turns up in drinking water.

That is also why the “universally compatible” claims on descaler listings deserve a second look. Urnex’s Amazon listing names Keurig, Nespresso, Breville, Jura and De’Longhi; De’Longhi’s names Breville, Ninja and Philips. Nespresso and De’Longhi themselves accept no other brand. The label on the descaler does not overrule the manual of the machine.

Vinegar, citric acid, lactic acid: what the chemistry says

Strength is not the problem

Vinegar is the weakest acid on the list — acetic acid’s pKa is 4.76, against 3.86 for lactic acid, about 3 for citric and about 1 for sulfamic, by PubChem’s figures — so it works more slowly. But it is not short of capacity. On paper, a gram of acetic acid can dissolve 0.83 g of calcium carbonate; a gram of citric acid 0.78 g; lactic acid 0.56 g. A litre of 5% vinegar could in principle dissolve about 40 g of calcium carbonate. Those figures are my stoichiometry, not a test, and they say nothing about speed. Urnex’s listing says its powder is “more effective at removing limescale than vinegar” and “works faster”; I found no controlled comparison behind that, in either direction.

What separates the acids is what they leave behind and what they do to the machine.

Citric acid’s own deposit

When an acid dissolves scale, the calcium does not disappear; it becomes a salt of that acid. For vinegar the salt is calcium acetate, which is extremely soluble: 374 g per litre at 0 °C and still 297 g at 100 °C. For citric acid it is calcium citrate, which dissolves at 0.85–0.96 g per litre at room temperature — some three hundred to four hundred times less.

Two studies explain when that matters. A 2016 study from the University of Copenhagen found that the common form, calcium citrate tetrahydrate, becomes less soluble as the water warms. And oil-industry research on dissolving limestone with citric acid found that calcium citrate precipitates once the solution’s pH rises to about 3 — as the acid gets used up — and forms a layer on the surface that slows further dissolving. Applying both to a coffee machine is my inference, not a test of one, but the picture is consistent: the risk is a spent solution — too little acid for the amount of scale — left hot and left long. A fresh, generous citric solution holds the calcium in solution.

That is the chemistry behind Moccamaster’s refusal of pure citric acid — “An incorrect concentration may not remove scale effectively and could damage the brewer” — while it approves Urnex’s measured citric-acid powders. It also fits the North Rhine-Westphalia consumer advice centre’s rule that acids should stay in a coffee machine only as long as descaling needs — “nicht über Nacht,” not overnight. One affiliate page in this search says citric acid “can create a different kind of build-up”; that is true, and calcium citrate is the build-up.

Seals: one engineering table

Nearly every page says vinegar damages rubber seals, and none gives a source. The nearest thing to evidence is the compatibility tables in the Parker O-Ring Handbook, the engineering reference published by Parker Hannifin’s O-ring division. Its ratings for four common seal rubbers:

Parker’s own caveat applies — “ALWAYS TEST UNDER ACTUAL SERVICE CONDITIONS” — and I do not know which rubber any particular machine uses. But the table points the same way as the makers who ban vinegar: of the common descaling acids, vinegar is the one a seal maker is least sure about, and citric acid the one it is most comfortable with.

How to descale a Breville espresso machine

Every Breville espresso machine I checked has a descale programme, and the instruction books point to the same product: one sachet of Breville’s descaling powder, the BES007, dissolved in a litre of water, with the water filter taken out of the tank first. Breville sold a pack of four for $14.95 on its own site on 14 October 2026, out of stock that day. The steps differ by model:

Two details trip people up. On the Barista Express the CLEAN/DESCALE light means two different things: flashing is a cleaning cycle — coffee oil, with a tablet, covered at the end of this piece — and solid is descaling. And the Dual Boiler is the one Breville manual that allows another product: “if an alternative cleaning solution is used, please follow the manufacturer’s instructions accordingly.” The others name only Breville’s.

Buyers rate the BES007 4.8 out of 5 on Amazon, and the most useful comment is about time rather than chemistry: “Four packets means roughly a year of maintenance if you descale quarterly.”

Drip, pod and high-end machines

A drip brewer whose manual says vinegar. Do it the maker’s way, and only with white vinegar. BUNN’s deliming uses a full quart and two hours; Ninja’s uses 16 oz topped up with water. NSF, the public-health standards body, describes the common method for a reservoir brewer — after telling you to follow the maker’s instructions first: up to four cups of undiluted vinegar, 30 minutes, then two or three cycles of fresh water. Rinse until you cannot smell it. One Amazon reviewer of a branded descaler said it plainly: “if you have a basic drip I’d just stick with vinegar.”

Moccamaster. No vinegar and no home-mixed citric acid; Urnex’s Dezcal or Biocaf every 100 brews.

Capsule and pod machines. Use the maker’s kit. Nespresso’s European safety sheet gives lactic acid, and its US guide says “every 3 months or 300 capsules (whichever comes first).” Keurig’s manual specifies Keurig Descaling Solution every three to six months.

De’Longhi. The company’s US support page is explicit — “use the De’Longhi descaler only” — and its descaler is the lactic-acid EcoDecalk, now sold as Decalk Care: 100 ml per descale, a 500 ml bottle for $19.95 on De’Longhi’s site on 14 October 2026. Amazon buyers rate it 4.7 out of 5, and a frequent complaint is practical — “No instructions in English,” with reviewers finding only other languages on the bottle. So: 100 ml in the tank, then the machine’s own descale function.

E61, heat-exchanger and dual-boiler machines. Here the advice reverses. ECM asks for water “with a hardness level of up to 4° dH” and says “A calcified machine should only be descaled by a qualified technician … as it may require partial disassembly of the boiler and tubing to prevent clogging of the entire system by limescale residues.” La Marzocco does not ask owners to descale at all: it specifies water at 70–100 ppm hardness, tells owners to drain the steam boiler every two months, inspects the boilers at service, and excludes “Problems relating to water damage, poor water quality and scaling” from its warranty. Clive Coffee, which sells several of these brands, tells customers to use soft water instead and to have a professional descale if it is ever needed. The reason is in ECM’s sentence: scale that breaks off a boiler wall in flakes goes looking for the smallest hole in the machine. Scale is also what several makers’ warranties refuse to pay for, which is part of how long an espresso machine lasts and when it needs a technician.

After descaling: rinse twice what the manual says

In 2013 the German Federal Institute for Risk Assessment (BfR) tested eight new coffee machines — three portafilter espresso machines, three pod machines and two capsule machines — for metals in the water, on three days before and three days after descaling with the agent and procedure each maker’s manual specifies. The published study is blunt: “After decalcification a large increase in the amounts of elements released was encountered,” and “By far the highest leaching … was found for the portafilter machines,” with lead, nickel, manganese, chromium and zinc within and beyond the limits the Council of Europe proposes. One of the three portafilter machines released far less than the others, which the authors read as proof that high release is “technically avoidable.”

The BfR’s advice to owners is specific: “The rinsing steps specified by the manufacturer should be repeated,” and on ordinary days, run a water-only rinse before the first coffee. It does not name the machines, and it calls its sample too small to be representative. Other tests point the same way without making it universal: Stiftung Warentest found increased lead from two of seven portafilter machines in 2021, while a Danish study of coffee machines in 2000 found no significant release at all.

None of that is a reason not to descale. It is a reason to treat the rinse as part of the job:

• Do the manual’s rinse twice. On a Barista Express that means two full 2 L tanks through all three paths; Urnex’s own directions already ask for three tanks.
• Throw away the first shots after descaling a portafilter machine.
• Check for leftover acid. Gaggia’s maintenance page suggests a baking-soda test: if water from the machine fizzes with baking soda, acid is still there. That tests for acid, not for metal, which is why the second rinse comes first.

How often to descale

As often as your water makes scale, which is why the makers tie it to a hardness setting or a warning light rather than a date. Their stated defaults:

The number that sets all of these is your water’s hardness. The U.S. Geological Survey calls 0–60 mg/L as calcium carbonate soft, 61–120 moderately hard, 121–180 hard and anything above very hard. Machine makers want less than brewing guides allow: the SCA’s brewing range goes up to 175 ppm, as the piece on the SCA water standard explains, while La Marzocco asks for 70–100 ppm and ECM’s 4 °dH works out to about 71 ppm. Water that tastes fine can still be harder than your boiler wants. Breville’s Barista Touch manual goes as far as telling owners whose water tests at level 4 or 5 to “change to an alternate water source.”

To find out where you stand, ask your water utility for its annual report or test it: an aquarium titration kit such as the API GH & KH measures hardness and alkalinity in a few minutes. Do not swing to the other extreme. Breville says never to use distilled water, and La Marzocco says water with too little mineral content can damage parts “through leaching.”

Backflushing: the other job

Backflushing pushes water — and, now and then, detergent — backwards through the shower screen and out through the three-way solenoid valve that relieves pressure after a shot. That valve is the precondition. Clive Coffee puts it bluntly: machines “with pressurized portafilters and no solenoid valve should never be backflushed.” If your manual has no backflush procedure, do not invent one.

Breville machines have a cleaning cycle instead: the grey silicone disc in the single basket, one BEC250 tablet on top, and the machine runs its own programme when the CLEAN light flashes. Its Dual Boiler manual also asks for a water-only backflush after each session — 20 seconds, five times. Amazon buyers rate the BEC250 4.8 out of 5, though its review summary notes buyers who received tablets that were not Breville’s; buy from a seller you trust.

Machines with a blind basket, the E61 and its relatives, use powder. Urnex’s directions for Cafiza: up to half a teaspoon (3 g) in the blind basket, ten seconds on and ten off, five times; five more without powder; then pull one shot through a normal basket and pour it away. For portafilters, baskets and the shower screen, soak them in 6 g per litre of hot water for 30 minutes, keeping the portafilter handle out of the water.

How often is where makers disagree, and both are right about their own machines. La Marzocco, writing for cafés, says “backflushing doesn’t harm the machine, so it’s better to do it more frequently.” ECM, writing for home E61 machines, asks for detergent every 90 to 140 cups and warns that cleaning the group with it more often can make it squeak and “will degrease all the moving parts and they will wear out quickly”; better, it says, to clean it from time to time without cleaner. Clive gives E61 owners every one to two months for the same reason — the detergent “strips the lubricant from the E61 assembly.” My reading of the difference, not either maker’s: La Marzocco was writing about café machines cleaned several times a day, ECM and Clive about the greased lever mechanism of an E61 at home.

If a spent puck sticks to the shower screen, the screen is the first thing to clean; the piece on wet pucks covers why.

What I would actually do

Read the manual before buying anything. It names the acid, the dose and the programme, and on most espresso and capsule machines it names one product. That instruction outranks every page in this search, including this one.

If it says white vinegar, use white vinegar — the full strength and time the maker gives, then rinse until the smell is gone.

If it names a descaler, buy that one. For a Breville that is the BES007; for a De’Longhi, the EcoDecalk; for a Nespresso, Nespresso’s kit.

If it names nothing, I would use Urnex’s Dezcal rather than mixing citric acid myself. It is citric acid with a little sulfamic acid, in measured 28 g packets; Moccamaster approves it; and Urnex publishes what is in it. On Amazon it is rated 4.6 out of 5 across more than 9,700 ratings, and the complaints are honest ones: one owner needed “a couple extra rinses” to lose a chemical smell, another thought it “may have caused some scarring on the chrome surfaces.” Rinse as you would after any acid. Do not use it in a Saeco machine, whose maker rules out sulfamic acid.

Rinse twice what the manual says, and pour away the first shots after descaling a portafilter machine.

Measure your water once. The hardness number decides how often you descale; a filter or softer water decides whether you need to descale much at all.

On an E61 or dual-boiler machine, prevent rather than cure. Keep the water inside the maker’s specification, and if it has scaled anyway, follow ECM’s advice and let a technician do it.

Backflush on the manual’s schedule, with water after each session and detergent only as often as the maker says.

Vinegar against citric acid is the question this search asks. The answer that protects the machine was printed before you asked it, in the manual that came in the box.