Extraction and chemistry
All questions in this silo, listed with their quick answer. Click for the full entry. — 68 questions.
What is Tetsu Kasuya's 4:6 method and how does it work?
The 4:6 method is a V60 pour-over technique developed by Japanese barista Tetsu Kasuya, winner of the 2016 World Brewers Cup. It divides the total brew water into two groups: the first 40% (the "4") w
How to brew Aeropress coffee?
Reference recipe: 15 g of medium-fine coffee (between V60 and espresso), 220 g of water at 85 °C, inverted method, 1:30 steep, flip and 25-30 s press. The result is a filtered, concentrated, balanced
Aeropress vs French press: which to choose?
The Aeropress produces a cleaner, more concentrated and technically more precise coffee — ideal for exploring the aromas of a specialty coffee. The French press produces a bolder, fuller-bodied coffee
What is batch brew coffee?
Batch brew refers to filter coffee produced in volume on an automatic drip machine, usually 1 to 2.5 litres per cycle, with a shower head that wets a large coffee bed and drains by gravity. In special
How to brew specialty coffee while traveling or camping?
Brewing specialty coffee while traveling is perfectly achievable with three elements: a quality hand grinder (compact, precise), a portable brewing method (Aeropress, travel V60, or Clever Dripper) an
How to brew Chemex coffee?
Chemex 6-cup recipe: 42 g of medium-coarse ground coffee (coarser than granulated sugar), 700 g of water at 94 °C, ratio 1:16.6. Fold and rinse the filter (three layers against the spout), bloom with
How to choose a brewing method by taste preference?
The choice lives at the intersection of three preferences: body (light/heavy), aromatic clarity (raw/clean) and intensity (light/concentrated). Clean and fruity cup: V60, Chemex, paper-filter Aeropres
How do you dial in an espresso?
Dialing in an espresso is the systematic process of adjusting extraction parameters — primarily grind size, dose, ratio, and brew time — to reach a target cup profile that is measurable and reproducib
What coffee-to-water ratio for espresso?
Modern espresso ratio is 1:2 — 18 g of ground coffee in for 36 g of liquid in the cup, in 25-30 seconds. Classic variants: ristretto 1:1.5 (18→27 g), normale 1:2, lungo 1:3 (18→54 g). The ratio is alw
How long should espresso extraction take?
A classic espresso pulls in 25 to 30 seconds at 9 bars, at a 1:2 ratio (18 g in, 36 g out). Some machines add a 5-10 s pre-infusion. Modern turbo shots cut it down to 8-15 s with a coarser grind. What
What grind size for espresso?
For espresso, the target grind sits around 200-300 µm — a fine powder that looks like table salt but denser and slightly clumpy. You dial it in precisely to pull a 25-30 s shot under 9 bars of pressur
Difference between espresso and moka pot?
Espresso is pulled at 9 bars of pressure on a dedicated machine, in 25-30 s, for 25-40 ml of intense coffee topped with crema. The moka pot (Italian stovetop) uses 1.5 to 2 bars of steam pressure to p
What water temperature for filter coffee?
For filter coffee, target water temperature sits between 92 and 96 °C. Below 90 °C, extraction stays underdeveloped (sour, watery); above 97 °C, it tips into over-extraction (bitter, astringent). The
How to brew with a French press?
Baseline recipe: 60 g of coarsely ground coffee for 1 litre of water at 93 °C (ratio 1:15 to 1:17), 4 minutes of steep, break the crust, skim the foam, let it settle 5 minutes, push the plunger slowly
What grind size for French press?
For French press, aim for a coarse grind around 900-1100 µm — close to coarse sea salt or fine breadcrumbs. That size lets water flow freely through the metal mesh without clogging, and keeps sediment
Difference between French press and V60?
French press is immersion with a metal filter: grounds steep in water all at once, then you press, yielding a full-bodied cup with oils and sediment. V60 is percolation with a paper filter: water pass
How to make a good home espresso?
A solid home espresso follows a simple recipe: 18 g of freshly ground coffee, 36 g in the cup (1:2 ratio), 25 to 30 seconds of extraction at 92-94 °C under 9 bars. The two non-negotiables are bean fre
How to adapt filter recipe to coffee origin?
Each specialty coffee origin has its own characteristics — bean density, acidity, sweetness profile, roast level — that influence optimal filter extraction parameters. A washed Ethiopian coffee (fruit
How to avoid over-extraction on a V60?
Over-extraction on a V60 manifests as a bitter, harsh or hollow taste, often accompanied by a drying mouthfeel. The main causes are: too fine a grind, too hot water, too long an extraction time, or to
How do you brew coffee in a syphon step by step?
Brewing coffee in a syphon takes 6 to 8 minutes and requires precise temperature and timing control. The key steps: fill the lower chamber with hot water, assemble the device, heat until water rises,
How to properly clean brewing equipment?
Coffee equipment cleaning should be daily for parts in direct contact with coffee (portafilter, group head, steam wand) and weekly for deeper components (hopper, grinding chamber, pipes). Coffee's oil
How to dose a 1L French press?
For a 1-litre French press, the recommended ratio is 60 to 70 grams of coffee per 1,000 ml of water — roughly 1 level tablespoon (6–8g) per 100 ml. This ratio falls within the SCA range for filter cof
How to foam milk for cappuccino?
To foam milk for a cappuccino, you need to incorporate air into warm milk using a steam wand, creating a vortex that homogenises the texture. The target is a microfoam — fine, velvety foam with no vis
How do you make a perfect Japanese iced coffee (flash brew)?
To make a great Japanese iced coffee, the key is adapting the recipe for ice dilution: use approximately 60% of the target volume as hot water and 40% as ice in the serving vessel. Brew with a filter
How to pour basic latte art?
Latte art relies on two distinct skills: creating perfect milk microfoam (velvety texture, invisible bubbles) and mastering the pouring technique to draw patterns on the surface. The two basic forms —
What is Japanese iced coffee (flash brew)?
Japanese iced coffee (also called flash brew) is an iced coffee method that involves brewing concentrated filter coffee directly over ice. Hot water extracts aromatics in real time, and the coffee is
What is the Kalita Wave and how do you use it?
The Kalita Wave is a flat-bottom coffee dripper with three small holes, made by the Japanese brand Kalita. Its design promotes uniform extraction and greater pour-tolerance compared to conical dripper
What is a lever espresso machine and how does it work?
A lever espresso machine is a type of espresso maker in which extraction pressure is generated manually by the user through a piston actuated by a lever or arm, rather than by an electric pump. There
How to make cold brew at home?
Home cold brew is made by steeping 100 g of coarsely ground coffee in 800 ml to 1 litre of filtered cold water (1:8 to 1:10 ratio), then letting it rest 12 to 18 hours in the fridge before straining.
How to make traditional Turkish coffee?
In a cezve, pour 60 ml cold water per cup and 7 g ultra-fine coffee, stir, then heat on low flame without stirring again. As soon as foam rises (around 90-95 °C), pull the pot, spoon the kaymak foam i
What is the difference between Melitta and V60?
The Melitta and the Hario V60 are both conical pour-over drippers, but their design differs on one essential point: the Melitta has a single small hole at the bottom (controlled flow, low technical ma
What is a melodrip accessory and what does it do?
A melodrip is a small stainless steel diffuser that attaches to the spout of a gooseneck kettle, breaking the water stream into multiple thin trickles before it hits the coffee bed. Its purpose is to
What grind size for moka pot?
For a moka pot, aim at a medium-fine grind around 350-450 µm — coarser than espresso, finer than V60. The texture sits close to fine table salt or powdered sugar. Too fine and the water stalls, scorch
What is pre-infusion in coffee and why does it matter?
Pre-infusion is an initial wetting phase in which coffee is exposed to low-pressure water or a small amount of liquid before the main extraction begins. Its primary purpose is to allow CO2 trapped ins
What is the Rao spin technique on a V60?
The Rao spin is an end-of-extraction technique on the V60 popularised by coffee consultant Scott Rao: at the end of the final pour, a gentle rotation is applied to the V60 (or the cup/server below) so
What is a signature espresso in barista competition?
The signature drink is one of three mandatory beverages at the World Barista Championship (WBC): a free-form creation where the barista designs an original espresso-based recipe — with or without addi
What is the difference between standard and inverted Aeropress?
The standard Aeropress (normal position) means placing the plunger at the top and pressing down onto a cup — the coffee flows by gravity from the start. The inverted Aeropress completely flips the dev
What is a syphon (vacuum pot) in coffee preparation?
The syphon, also called a vacuum pot or vacuum brewer, is a coffee preparation device invented in Germany in the 19th century and popularized in Japan. It works by pressure differential: hot water ris
How to use a moka pot?
To brew a clean moka: fill the base with already-hot water (around 90 °C) up to just below the safety valve, load the basket with medium-fine coffee untamped, screw the parts together, place on medium
What ratio for V60 brewing?
Standard V60 ratio is 1:16 to 1:17 — 15 g of coffee to 240 ml of water, or 60 g of coffee to 1 litre. That ratio targets a cup TDS of 1.25-1.45 % and an extraction yield of 18-22 %, landing squarely i
What grind size for V60?
For V60, aim at a medium-fine grind around 500-700 µm — close to caster sugar or fine sand. Total drawdown target is 2:30 to 3:15 for 15 g of coffee and 240 ml of water at 92-96 °C. You tune via grind
How to brew V60 step by step?
Classic V60 recipe: 15 g of medium-ground coffee (sea-salt sized), 250 g of water at 93 °C (ratio 1:16.6). Rinse the filter, bloom with 30-45 g of water for 45 s, then continue with spiralled pours up
Difference between V60 and Chemex?
V60 and Chemex are both cone pourovers, but they pour very different cups. Hario's V60 (60° cone, spiral ribs, large hole) gives a fuller-bodied, more aromatic, edgier cup. The Chemex (70° cone, thick
What is a café mocha?
A café mocha is a drink made from espresso, chocolate (sauce, powder or cocoa), and steamed milk, usually finished with a dollop of whipped cream. It is one of the most popular coffee-chocolate drinks
What is a cappuccino?
A cappuccino is an Italian drink built from one espresso (about 30 ml) and textured steamed milk in near-equal thirds — roughly one-third espresso, one-third hot milk, one-third microfoam — for a 150
What is a Chemex?
The Chemex is an hourglass-shaped borosilicate glass coffeemaker invented in 1941 by German-born chemist Peter Schlumbohm in the United States. It uses a proprietary paper filter 20 to 30 % thicker th
What is a cortado?
A cortado (from Spanish 'cut') is a drink composed of an espresso and an equal — or slightly greater — amount of warm milk, in a ratio of approximately 1:1 to 1:2. The goal is to 'cut' the acidity and
What is a flat white?
The flat white is an espresso-milk drink from Australia and New Zealand, born in the 1980s, served in a 150-180 ml cup. It pairs a double espresso or ristretto with milk steamed into a thin, flat micr
What is a French press?
A French press — also called a cafetière or plunger pot — is an upright glass or steel carafe in which coarsely ground coffee is steeped for about 4 minutes, then separated by pushing a mesh plunger d
What is a latte?
A latte — short for 'caffè latte' in Italian, literally coffee with milk — is a drink built on an espresso (30 to 40 ml) lengthened with textured steamed milk, for a total volume of 220 to 300 ml. The
What is a lungo?
A lungo — Italian for 'long' — is an espresso stretched at extraction: same dose (7-9 g or 18 g double), but a yield of 60 to 90 ml instead of the standard 25-40 ml, obtained by letting more water run
What is a macchiato?
A macchiato (Italian for 'stained' or 'marked') is a short espresso — 20 to 30 ml — 'stained' with a small amount of warm milk or milk foam, typically 5 to 10 ml. It comes in two main forms: hot macch
What is a moka pot?
A moka pot — also called the Italian coffee pot — is a stove-top percolator in three parts: water chamber at the bottom, ground-coffee basket in the middle, collection chamber at the top. Heat turns w
What is a percolation brewing method?
Percolation is an extraction method where water passes through the coffee by gravity (or under pressure) just once, without prolonged contact with the grounds. Filter coffee (V60, Chemex, electric dri
What is a ristretto?
A ristretto — 'restricted' in Italian — is an espresso pulled shorter: roughly 15 to 20 ml from 7-9 g of coffee (about a 1:1 to 1:1.5 ratio) instead of the standard 25-40 ml shot. The result is denser
What is a V60 pourover?
The V60 is a 60-degree conical dripper developed by Japanese glassmaker Hario in 2004, used to brew manual pourover coffee. Its geometry — a wide cone angle, internal spiral ribs and one large exit ho
What is an Aeropress?
The Aeropress is a portable plastic coffeemaker made of a brewing tube and a piston, invented in 2005 by American engineer Alan Adler (also the designer of the Aerobie flying ring). It combines short
What is an affogato?
An affogato (Italian for 'drowned') is a traditional Italian dessert-drink made of one or two scoops of vanilla ice cream over which a shot of hot espresso is poured at the moment of service. The heat
What is an americano?
An americano — or caffè americano — is an espresso (30 to 40 ml) lengthened with hot water (100 to 180 ml) to reach a filter-coffee volume while keeping an espresso-derived aromatic profile. The name
What is an espresso?
An espresso is a coffee extracted under pressure — 9 bars of water at 92-94 °C forced for 25 to 30 seconds through 18 to 20 g of finely ground, tamped coffee, yielding roughly 36 to 40 g of concentrat
What is an espresso tonic?
An espresso tonic is a cold drink made by pouring a shot of espresso over chilled tonic water. The carbonation of the tonic and the bitterness of the espresso create a refreshing gustatory tension, es
What is an immersion brewing method?
An immersion brewing method is an extraction technique in which the ground coffee remains in constant contact with the water throughout the entire brewing period, before being separated by filtration
What is brew ratio and how to calculate it?
The brew ratio is the relationship between the mass of coffee and the mass of water used for a preparation, expressed in grams per litre (g/L) or as a fraction (1:15, 1:16, etc.). It is the most funda
What is bypass brewing technique?
Bypass brewing involves deliberately extracting a more concentrated coffee than the final target, then diluting it with a precise amount of water (the 'bypass') to reach the desired volume and concent
What is cold brew coffee?
Cold brew is coffee made by steeping coarsely ground beans in room-temperature or chilled water for 12 to 24 hours, then filtering. Cold extraction produces a naturally sweet, low-acid and very low-bi
What is nitro cold brew?
Nitro cold brew is coffee brewed cold for 12 to 24 hours, then charged with nitrogen gas (N₂) and served on tap through a restrictor nozzle. The nitrogen creates an ultra-creamy texture, a dense foam
What is traditional café au lait?
Traditional Belgian or French café au lait is a breakfast drink made of approximately equal parts of strong filter coffee and hot milk, served in a large bowl or mug. It is not an espresso with milk,
What is Turkish coffee?
Turkish coffee is a decoction method brewed in a small long-handled pot called cezve (or ibrik), using an ultra-fine grind close to powder, heated slowly without a hard boil. The grounds are never fil