Koch-Chemie Leather Star "Ls" Leather Care 1000ml

Koch-Chemie Leather Star keeps vehicle leather supple and matt

What is Koch-Chemie Leather Star "Ls"? A ready-to-use leather-care emulsion with cosmetic esters and active UV blockers for smooth leather, perforated leather and Velour on car seats, sofas and leather consoles. It doesn't seal — it leaves a satin-matt OEM look without a greasy shine. Not for Alcantara, long-pile suede or cracked patent-leather surfaces.

Koch-Chemie Leather Star "Ls" is a leather-care emulsion from Koch-Chemie in Unna that re-greases polyurethane-coated leather with cosmetic actives and shields it from light-driven fading with dedicated UV blockers. The formula carries 10 to 25 weight-percent aliphatic hydrocarbons of the C10–C13 range (per safety data sheet) as a volatile carrier and an antibacterial preservative (Bronopol, under 0.1 percent).

The carriers move cosmetic esters through the micropores of the PU coating down to the collagen fibres and then flash off without residue. What's left behind isn't a sticky wax or oil film but a hair-thin layer inside the fibre matrix — that's what makes Leather Star fundamentally different from Carnauba or beeswax-based dressings, which clog pores and cut breathability.

With normal day-to-day car use the dressing carries for three to six months; in summer with heavy UV and bare legs against the driver's seat, the interval tends to the short end.

• Satin-matt look, no greasy film. On the seat surface you get a colour-deepening effect that isn't shiny — no show-car wet look and no slippery surface. Verified buyers at Trusted Shops put it plainly: "cares for the leather without leaving a greasy shine". This matters on BMW or Audi seats with perforated leather, where any shine reads like sweat.
• One litre handles roughly ten car interiors. Real-world use lands around 100 ml per full interior — that's 15 to 20 pea-sized drops per seat cushion. About €1.40 per seat from the 1-litre bottle; in the 3×1 L bundle the per-seat cost drops to about €1.30. The saving versus wax pastes comes from the yield, not the per-litre price.
• Cleared for premium furniture too. Koch-Chemie's data sheet calls out "vehicles, furniture etc." as the field of use. One Detailing1 customer uses it on a De Sede sofa alongside her car seats. Aniline-leather houses like De Sede, Vitra or USM Haller benefit most, because the low-viscosity emulsion sinks into the open fibre matrix instead of sitting on top.

Detailing1's tip from the shop: The most common mistake is over-application. Lay Leather Star on thick and you get a shiny halo on the bolsters and a greasy, slippery film on the cushion. The rule we use in the bay: 15 to 20 pea-sized drops on a microfibre applicator per seat cushion, worked in circular motions and thin as a whisper. With perforated leather, follow up with a soft brush over the holes — otherwise the product dries white inside them. After 5 to 10 minutes' dwell, buff the shine off with a dry microfibre — that's when the OEM look lands.

Pol Star first, then Leather Star. Lay it down thin.

The standard workflow on vehicle leather starts with cleaning, not with dressing. First you run Pol Star "Po" as a pH-neutral textile and leather cleaner, work it in, lift it off with a damp microfibre — and then let the leather dry through completely.

This is the most-missed step: put Leather Star onto leather that's still damp and you block fibre penetration outright. The hydrophobic emulsion can't enter a water-saturated fibre structure — it just sits on the surface as a streaky film. On a dirty seat the other way round, the dressing locks sweat and skin oils into the leather pores — a mistake that only shows up after weeks, but then for good.

Onto clean, dry leather go 15 to 20 pea-sized drops per seat cushion on a soft microfibre applicator. Work in circular motions across the panel without running over the seat edges.

A bolster needs less than a cushion, perforated leather less than smooth leather with a dense grain pattern. On the centre console and the leather steering wheel one single drop per part is enough.

With pigmented aniline leather (often in BMW Individual, Bentley or Rolls-Royce) you work fast, because the open-pore fibre pulls the emulsion in quicker — uneven saturation leaves tonal patches. Let it dwell for 5 to 10 minutes until the surface goes dull-matt. On heavily used bolsters a treatment every two to three months is enough; on normal car use every four to six months.

Smooth, perforated, Velour. Not Alcantara.

Leather Star is explicitly cleared for smooth leather, perforated leather and Velour leather — the leather types you find in interiors from an Audi A4 in standard trim up to a BMW M3 with full-leather sport seats. The low-viscosity emulsion doesn't sit in perforation holes as white residue, it pulls through — that's the edge over wax pastes.

On the protection side, the formula works in three stages: re-greasing the collagen fibres keeps the leather supple and mechanically tough; an anti-adhesion effect on the PU coating cuts friction and jeans-transfer; dedicated UV blockers actively shield against photochemical breakdown and light-driven fading. On convertibles and cars with light leather the UV block carries the heavy lift — without active protection, light aniline leather can fade visibly in a single summer of convertible use.

There are hard limits too. Alcantara isn't leather, it's a synthetic microfibre fabric of polyester and polyurethane — the greasing emulsion glues the microfibres together permanently and triggers pilling. For Alcantara the right tool stays the bare Pol Star without a follow-up dressing. With vinyl-coated faux leather you can dress the surface, but the material doesn't take up the re-greasing components — a thorough wipe-down afterwards is non-negotiable. On already-cracked patent-leather surfaces you need a repair product from the COLOURLOCK line, not a dressing.

For pro detailers and shops there's one more thing: Leather Star carries 12.35 percent VOC (Swiss VOC-CH regulation). With several applications a day in closed reconditioning bays, ventilation is required — doors wide open or extraction running — plus nitrile gloves because the carriers de-grease your skin (EUH066 in the SDS).

If you've got classic smooth or genuine leather and want a ready-to-use top-up every few months, Leather Star is the call. Pro detailers running ten cars a week have the concentrate sibling in COLOURLOCK Leather Care — same maker, same formula family, different dilution logic.

Three bottle sizes, three buyer profiles.

The 1-litre bottle at €14.23 is the easy starting point for one or two cars in a private household. With care intervals every four to six months it works out to about ten full car interiors — three to four years for a single car. The bottle itself stays good for 24 months after opening, frost-free and sealed in the original container.

The 2×1 L set at €27.89 saves you roughly 50 cents per litre versus the single bottle. It fits households that look after a car and leather furniture together — high-end manufacturers like De Sede, Vitra or USM Haller build their seating with aniline or semi-aniline leather.

For furniture, once or twice a year after a thorough dust-down is enough, because living-room furniture doesn't take the UV and temperature beating a car interior does. The colour-deepening effect comes out strongest on open-pore aniline.

The 3×1 L bundle at €41.41 fits smaller detailers, shops without 5-litre storage and fleets of three to five vehicles. Per litre you're at about €13.80, which drops the per-seat anchor to around €1.30. If you burn through a full 1 L bottle per quarter, that's the volume that turns over without storage risk — four to five jobs a month.

Seasonally, two windows make sense to buy: spring detailing between March and May when convertibles come out of winter storage, and the autumn impregnation between October and November before the dry heating air hits the interior. Both peaks land in DACH search behaviour too, and they're the weeks when Leather Star tends to be most readily available.

The Detailing1 tip the maker doesn't write down: the smell of a fresh application is creamy-chemical and fades within about 48 hours. If you're picking up a passenger on the same day, ventilate well beforehand or do the job at the weekend with the doors open. On perforated seats with ventilation, one more thing: leave the seat-vent switch off until the next morning — otherwise the ventilation pulls the smell into the cushion fill, and it sticks around noticeably longer than the standard 48 hours.

Application of Koch-Chemie Leather Star "Ls"

Clean, apply thinly, massage in, buff off.

Before conditioning, clean the leather with Pol Star "Po" — spray on the cleaner, work in with a soft sponge, wipe off with a damp microfiber cloth and allow the leather to dry completely. Only then apply Leather Star to the clean, dry leather. On a still damp fiber, the hydrophobic emulsion will leave streaks, and on a dirty seat, it will permanently trap sweat and skin oils.

Shake the bottle vigorously. Apply 15 to 20 pea-sized drops per seat cushion (surface, backrest, bolsters combined) onto a clean microfiber applicator or soft sponge — for an entire interior, calculate about 100 milliliters, which is about ten complete treatments per 1-liter container. Distribute evenly over the leather surface in circular motions, without going beyond the seat edges.

For perforated leather, additionally run a soft brush over the rows of holes to prevent any material from remaining in the perforations. For pigmented aniline leather, work quickly, as the open-pored fiber absorbs the emulsion faster — uneven saturation can otherwise cause toning stains.

Allow Leather Star to act for 5 to 10 minutes until the surface appears dull-matte. If there is still shine: take a second dry microfiber cloth and buff off the excess. Allow to dry for at least one hour before the next use of the seat, ideally overnight in a ventilated interior.

Notes: Leather Star is approved exclusively for smooth leather, perforated leather, and velour — not for Alcantara, long-pile suede, or already cracked patent leather surfaces, where a repair product from the COLOURLOCK line is needed. The formula contains 12.35 percent volatile organic compounds (VOC) — for commercial use in enclosed detailing halls, ventilation and nitrile gloves are mandatory. The fresh conditioning scent is creamy-chemical and dissipates within approximately 48 hours; for perforated seats with ventilation function, only switch on the ventilation the next morning, otherwise the smell will penetrate the upholstery filling. Store frost-free in the sealed original container between 5 and 30 °C, use within 24 months after opening. Maintenance interval: every 4 to 6 months for normal car use, every 2 to 3 months for heavily stressed seat bolsters, once or twice a year in a furniture context.