System Büttner coffee maker

"System Büttner" coffee makers (German: Büttner-Kaffeemaschine ) have been a type of manual and semi-automatic coffee makers combining coffee steeping (infusion, full immersion) with drip-filtering (percolation).

Overview
The idea to combine steeping with drip-filtering was utilized by Berlin-based coffee roaster Carl Artur Büttner (also written as Carl Arthur Büttner) in his 1926 invention of a manual zero-bypass flat bottom coffee maker consisting of four parts, all made out of porcelain: a filter pot (Filtergefäß / Oberteil, "O") with lid (Deckel, "D"), saucer (Ablaufteller / Unterteil, "U") and coffee pot (Kaffeekanne, "K"). The filter pot featured a through-glazed porcelain filter with triangularly-arranged slits with some air space below. Steeping was achieved through a valving mechanism stopping the flow through the filter through a specially designed rotatable saucer with a single hole,    which had to be positioned between the filter pot and the coffee pot so that the hole was initially closed and was opened, when the coffee had been steeping for three to five minutes. Once released, it then took between four to six minutes for the coffee to drip through the meanwhile settled coffee bed into the coffee pot, a method sometimes also called cake filtration.

Marketed since spring 1927 and up into, at least, the 1940s, these coffee makers were available as stand-alone devices for home use, but were also adopted by various other German coffee roasters (including Maschinenfabrik Bremen (Bremen, Germany), Georg Schrader & Co. aka Geschraco (Bremen, Germany), Ferdinand Eichhorn (Braunschweig, Germany), Heimbs & Sohn Co. (Braunschweig, Germany) and Columbus (Germany)) as part of larger coffee machines produced by the porcelain manufacturer Bauscher (company) (Weiden, Germany) for heavy-duty semi-continuous batch use in restaurants and canteens. The Büttner extraction method was boldly marketed claiming to be the world's best moka and coffee filter ("Der beste Mokka- und Kaffeefilter der Welt").

Properties were said to be:


 * 100% porcelain, no contact with metal, enamel, or paper impacting the taste
 * Permanent filter requiring no paper filter or bags, thereby reducing costs
 * Claim to have no tendency of clogging the filter sieve holes (compared to Karlsbad-style coffee makers)
 * Full aroma, claimed to have up to 30% increased extraction efficiency (also called "Kaffeesparmaschine"), thereby reducing costs
 * Reduced amount of oily components and caffeine in finished coffee (will be floating on top of the water column in filter pot and claimed to be filtered out by settled coffee bed, a method sometimes called cake filtration)
 * Easy to clean by just washing out with water
 * Possibility to draw coffee from the coffee pot even before the coffee preparation process has stopped (just by temporarily opening the valve to draw a cup of coffee and then closing it again)
 * May need preheating of the porcelain due to longer than normal extraction time
 * Needs coarser than normal coffee grounds (semolina-grade)

Forms and sizes
Known forms include:


 * Büttner / Bauscher: [O/U/K/D] 1423/1, [O/U/K/D] 1423/2, [O/U/K/D] 1423/3, [O/U/K/D] 1423/4, [O/U/K/D] 1423/5
 * Bremer Kaffeemaschine / Bauscher Weiden: 1518/3,00 (3 litre)
 * Ferd+Eichhorn Braunschweig / Bauscher Weiden: [O/U/K/D] 1521/4
 * Büttner / Bauscher: [O/U/K/D] 1521/3, [O/U/K/D] 1521/5
 * Bauscher Kaffeesparmaschine System Büttner: 1550/100 (1 litre)
 * Büttner / Bauscher: 1560/0,80 (0.8 litre), 1560/1,40 (1.4 litre), 1560/2,00 (2 litre)
 * Heimbs & Sohn Braunschweig: 1560/3,00 (3 litre)
 * Geschraco / Bauscher Weiden: 1755/1,00 (1 litre)
 * Columbus / Bauscher Weiden

Sizes:


 * Size 1: 0.5 litre
 * Size 2: 0.75 litre
 * Size 3: 1.5 litre
 * Size 4: 3 litre
 * Size 5: 6 litre