The Swiss Gold is a permanent single-cup pour-over made of an electroformed metallic foil with elongated slot openings, plated in 23-karat gold. It was invented in Switzerland by Elfo AG — the name comes from "electroforming," the galvanic process they developed to produce precise filter foils. The standalone single-cup model, the KF300 (also sold in the US as the Frieling "Coffee For One"), was refined in the mid-1990s and is the version most specialty drinkers mean when they say "Swiss Gold filter."
Unlike a V60 or Kalita, the Swiss Gold has no paper. The brewer is a three-part assembly — lid, plastic top, gold-foil cone — that sits directly on the mug. The plastic top doubles as a water regulator: pour your full dose of water in once and the dispersion plate meters it down over the bed without agitation, in a slow, even stream. The cup that lands is fuller than paper pour-over, lighter than French press, with the aromatics of a metal-filter brew and a small amount of fine sediment at the bottom — noticeably less than a press pot, more than paper.
Because the foil passes oils, diterpenes like cafestol and kahweol travel into the cup. Worth knowing if you watch cholesterol.
A starting recipe: 15 to 17 g of coffee to 225 g of water (1:15), medium-fine grind, water at 93 to 95 °C, drawdown around 2:30. The brewer is sensitive to grind and dose — too fine and it stalls, too coarse and it gushes. The Swiss Gold is not a Chemex insert: paired with a Chemex it produces a murky cup that an Able Kone serves far better. Used as it was designed — directly over a mug, lid on, water dosed by the regulator — it is one of the simplest paperless brewers ever made.