Sugar spilled on the glass is the one kind of mess you must not wait to remove. It is written in your induction hob manual, two lines below the rule that says to clean only when the hob is cold, and almost nobody reads that far.
At PortosEunostos we placed two sources from the same manufacturer side by side: the instruction manual of a Bosch induction hob and the service pages on the Bosch website. They disagree on three points, and one of the three is the one that ruins the glass for good. Below is the procedure, including which source wins when the two conflict.
The cold rule has one exception
The Bosch manual starts with a blunt requirement: the hob must be cold. Then comes the line that changes everything: with stains of sugar, rice starch, plastic or aluminium foil, you must not let the hob cool down.
The reason is physical: those four materials melt and, as they cool, they bond to the ceramic glass. If you wait, you are no longer removing a stain, you are prising off something that has become one with the surface, and a piece of the finish comes away with the crust. The result is a permanently dull patch.
So the real rule is a double one: sauce, oil and boiled-over milk are cleaned cold, while sugar, rice, plastic and aluminium come off straight away with the scraper while the hob is still hot, using the handle and keeping your hand clear. The guide on the Bosch website says instead to always wait for the hob to cool, but it is a text written for every type of hob: when the two sources conflict, your appliance manual wins.
The three steps, in the right order
The manufacturer procedure is short and allows no shortcuts:
on stubborn dirt you first use the scraper, blade angled and never pointed;
you spray the whole surface with soapy water or ordinary washing-up liquid, applied evenly and gently;
you wipe with a damp cloth and dry with a second cloth.
The third step is the one everyone skips, and it is not about looks: water left to evaporate on its own leaves limescale, the only stain that really forces you to buy a dedicated product. Thirty seconds with a dry cloth removes the problem at source.
Washing-up liquid or a dedicated cleaner?
Here the two sources diverge. The manual says to use a ceramic hob cleaner only for stubborn dirt. The Bosch service page says instead not to use traditional household detergents, too aggressive, and recommends its own cleaner for ceramic and induction hobs.
Both can be true once you read what "traditional household detergent" means: all-purpose degreasers, bathroom limescale removers, bleach-based products. Washing-up liquid is not in that family, it is neutral, and it is exactly what the manual authorises you to use every day.
In spending terms: for daily cleaning, what you already have by the sink is enough. The dedicated product is for limescale and old deposits, because it leaves an invisible film that slows down the return of marks, but it is a monthly exception. One detail: Bosch lists the ceramic glass cleaner (00311900) and the glass scraper (17000334) as two separate items.
What must never touch the glass
Steam cleaners and pressure washers. The manual forbids them: moisture getting into the appliance can cause an electric shock. It is a safety warning, not a tip.
Metal scourers, hard sponges, the green side of the sponge, abrasive powders. They are the main cause of scratches and Bosch says so openly.
Neat bleach and caustic soda, and ammonia-based glass sprays on hot surfaces or on brushed steel, because they stain.
Cold water on a hot surface. Thermal shock, and ceramic glass does not forgive it.
Hob covers and protective grids. The manual forbids both because of overheating, flames and spattering. They are sold, but the manufacturer says not to use them.
Metal objects left on the hob, such as knives and lids: they get very hot immediately and scratch the glass the moment you move them.
Scratches do not come out
Bosch is categorical here: scratches cannot be removed from a ceramic glass hob by polishing it. No product makes them disappear, and the ones that promise to usually leave the glass dull. Six months of using the abrasive side of a sponge cannot be undone: the damage is only cosmetic, but you see it every time you walk into the kitchen. On a glass hob, real maintenance is prevention.
Pans make more mess than sauce
The manual closes its cleaning section with three lines that matter more than all the rest: rough pan bases, salt, sugar and sand cause scratches and discolouration, they must be removed at once, and the pan must be lifted and not pushed.
In practice: keep the bottom of your pans clean and the hob looks after itself, while a grain of salt under a dragged pan is a guaranteed scratch. The cooking zone and the pan base should also be kept dry, because liquid trapped in between can make the pan jump. It is one of the practical differences between induction and gas that you notice more than the running costs.
If the glass cracks, pull the fuse
A cracked or broken surface is not cleaned, it is taken out of service. The manual asks you not to use the appliance and, a detail almost nobody knows, to switch it off at the fuse in the consumer unit and not at the hob switch, then to call service.
At that point the question becomes economic. The price of a replacement glass depends on the model and only the service centre can tell you: ask for the quote and put it next to what a new hob costs today, because at entry level the gap is narrow. For a sense of real prices you can compare offers on SniffaPrezzi and check availability and specifications on OpportunityCommerce. As an entry-level reference, here is the spec sheet of the Bosch PUE611BB5D.
PortosEunostos advice
What to check on the product. A frameless hob is easier to clean than one with a steel frame, because it has no edge where grease builds up and where the scraper cannot reach. The frame, if there is one, needs a different product from the glass. Check too that the manual can be downloaded from the manufacturer website: it is the document you will keep going back to.
How to judge the seller. Real availability, stated lead times, returns policy and above all an authorised service centre in your area, because the day you need a replacement glass that is the only thing that counts. The useful reviews are the ones about delivery and after-sales. If you are sorting out the whole kitchen, here is our method for cleaning an oven without pyrolysis.
The Portos verdict
Cleaning an induction hob costs two minutes after dinner and a drop of washing-up liquid. Everything else, dedicated products included, exists to fix something you did not do straight away. Keep a scraper within reach for melted sugar, always dry with a clean cloth, never let anything abrasive touch the glass: scratches are the only irreversible part of this story.
If the bill matters too, we worked out dish by dish how much an induction hob really consumes.
Sources
Bosch, induction hob instruction and installation manual, document 9001867238_E, Italian section, "Cleaning the hob" and "Safe use".
Bosch, cleaning an induction hob.
Data verified on 18 October 2026.
