


Koch Chemie · Germany · Wash & Pre-Wash
pH Neutral Foam Soap · Wax, Sealant & Ceramic Safe · Active Foam Capable
Thick, cherry-scented, and protection-safe. The foam that works alone — or steps up when you add Green Star.
GSF is Koch Chemie's answer to the question every detailer eventually asks: what's a foam soap that's actually safe on everything I've spent time protecting? pH neutral means it's not stripping wax, pulling at a sealant, or degrading a ceramic coating.
What makes this interesting beyond just being "safe" is the one-and-done foam chemistry. GSF is formulated to foam up once — when it hits the surface — and not reactivate during the rinse. That's unique. Soaps that lather back up during rinsing drag out the process and leave residue you end up chasing. GSF sheets off clean. The rinse step is faster and you're not standing there wondering if you got it all.
It's also legitimately thick, and legitimately cherry-scented. Not a suggestion of cherry — the scent is there. That's worth mentioning because it makes the wash noticeably more enjoyable, and the viscosity means it behaves correctly in a foam cannon, clings to vertical surfaces, and gives you reasonable dwell time rather than sheeting straight off the moment it touches paint.
What it does
pH neutral — protection stays intact — won't interact with wax, sealant, or ceramic coatings. Safe for regular maintenance washing on anything that's been protected.
Foams once, rinses clean — formulated not to reactivate during rinsing. The foam lifts with the dirt, sheets off cleanly, and doesn't fight you during the rinse step.
Thick blanket coverage — high-viscosity formula clings to vertical panels and wheel arches, giving the chemistry real dwell time instead of sliding off immediately.
Two-mode versatile — runs as a no-contact snow foam pre-wash through a foam cannon, or as a shampoo in a wash bucket with a mitt. Same product, different dilution.
Green Star compatible — add 10–30 ml of Koch Chemie Green Star to create an active foam with genuine alkaline cleaning power for heavier contamination, bugs, and road film. I think this is where AF originated!
How You'll Run It
The Active Foam Setup: Mix your GSF solution first at the standard snow foam ratio, then add 10–30 ml of Green Star directly into the cannon bottle. GSF acts as the carrier — it extends dwell time and holds the alkaline cleaner on the surface longer than Green Star alone would allow. More contact time means more cleaning power without hot alkaline chemistry drying unsupported on a finish. The right call when you're dealing with heavy contamination, a winter-beaten car, or bugs that a pH-neutral foam won't fully cut through on its own.
How to Use
Dilute to mode — 20 ml per liter for snow foam pre-wash; 50 ml per 10 liters for hand wash. Measure it — the product is concentrated and ratios matter.
Optional — add Green Star — for heavier contamination, add 10–30 ml of Green Star to the pre-mixed GSF in your cannon. GSF carries the alkaline cleaner and extends its dwell time on the surface.
Apply top-down and dwell — foam from the roof down. Let it sit 3–5 minutes. The foam clings — let the chemistry work before you touch anything.
Rinse before it dries — high-pressure rinse, top down. GSF sheets off without reactivating. If following with a contact wash, proceed to mitt wash with fresh bucket solution.
"This soap is phenomenal. If it came in a body wash I'd definitely purchase it."
— Verified Buyer