What 1:16 means
One part coffee by weight to sixteen parts water by weight. 25 g of coffee takes 400 g of water, and since water is 1 g per mL that is 400 mL, or 13.5 US fluid ounces. Both sides go on the same scale, which is why brewing by weight is simpler than it sounds: put the carafe on the scale, zero it, and pour to the number.
Smaller second number means stronger. The Specialty Coffee Association's reference figure is 55 g per litre, which works out to 1:18.2, and a lot of people find that thin. Most cafés and most home brewers land somewhere between 1:15 and 1:16.5. That is where the defaults here sit.
The carafe cup problem
A drip machine's "cup" is 5 fluid ounces, not 8. A 12-cup carafe holds 60 fluid ounces, about 1.77 litres. The scoop that came in the bag is 2 tablespoons, about 10.6 g of grounds. Follow the machine's own instructions — one scoop per cup — and you get 12 scoops, roughly 127 g, into 1,774 g of water: a ratio of about 1:14, considerably stronger than the machine's marketing implies and stronger than most people expect. Follow the "1 tablespoon per cup" version instead and you land near 1:28, which is weak brown water.
This is why the same machine produces coffee that varies from bitter to insipid with no apparent change in what anyone did. The units on the machine do not match the units on the bag or on any measuring cup in the house. Weighing both sides once tells you what your machine actually wants, and the answer stops moving after that.
Ratio and extraction are separate dials
Strength and taste are controlled by different things and confusing them is the most common way to chase a problem in circles.
Ratio sets strength — how much dissolved coffee ends up per unit of water. If the cup tastes correct but too intense or too watery, move the ratio.
Extraction sets flavour — how much of the available material actually came out of the grounds. Grind size, water temperature and contact time all move it. Sour, thin and salty means under-extracted: grind finer, use hotter water, or brew longer. Bitter, dry and hollow means over-extracted: grind coarser, cool the water, or cut the time short.
Change one at a time. If the coffee is both weak and sour, the fix is grinding finer, not adding more coffee — adding coffee to an under-extracted brew gives you more under-extracted coffee.
The two methods that do not follow the pattern
Espresso's ratio is dose to yield: the dry weight in the basket against the liquid weight in the cup, ignoring whatever water the machine pushed through and left behind. 18 g in and 36 g out is 1:2, the modern default, in 25 to 32 seconds. A ristretto is nearer 1:1.5 and a lungo 1:3. Time is a symptom rather than a target — if the shot runs fast, the grind is too coarse.
Cold brew's ratio makes a concentrate, not a drink. At 1:8 the result is roughly three times drip strength and gets cut with water or milk before serving, typically 1:1 or 1:2. The grounds also keep about a quarter of the water, so the volume you pour off is meaningfully less than the volume you put in — plan for that when you are working out whether a batch fills the bottle.
Water temperature without a thermometer
Off the boil and left to stand a minute is about 200 °F, which is where nearly everything wants to be. Pouring boiling water from the kettle into a separate serving pot drops it 5 to 10 degrees on its own. Light roasts take heat well and can go right to the boil; dark roasts extract easily and get harsh above about 200 °F, so give them a longer wait. The variable most people ignore is the water itself: heavily softened or distilled water makes flat coffee no matter what the ratio says, because the minerals are part of how extraction works.
Questions people ask
How much coffee for a 12-cup pot?
A 12-cup carafe is 60 US fluid ounces, about 1,774 g of water. At 1:16 that is roughly 111 g of coffee, which is about 10.5 level tablespoons or a little over five two-tablespoon scoops. If you like it stronger, 1:15 gives 118 g. Note that this is nowhere near the "one scoop per cup" on the machine, which would be 12 scoops and about 127 g — a much stronger 1:14. Neither is wrong, but knowing which one you are doing is the difference between reproducible coffee and guessing.
How many grams is a tablespoon of coffee?
About 5.3 g for medium-grind coffee, so the standard two-tablespoon scoop is about 10.6 g. Whole beans measure lighter, nearer 4.5 g per tablespoon, because they pack with more air between them. Both figures move by 20% or more with roast level and grind size — dark roasts lose density in roasting, and fine grinds settle tighter than coarse. Volume measurement is the single largest source of inconsistency in home brewing, and a 0.1 g scale is cheaper than most of the other things people buy to fix their coffee.
My coffee is bitter. Should I use less coffee?
Probably not, and this is the reflex that keeps people stuck. Bitterness is usually over-extraction, meaning too much came out of the grounds — the fix is a coarser grind, cooler water, or a shorter brew. Using less coffee against the same volume of water makes it worse, because a smaller bed of coffee facing the same water extracts harder. If the coffee tastes right in character but simply too intense, that is a ratio problem and less coffee is the correct answer. Bitter and drying is extraction; strong but pleasant is ratio.
Is the ratio the same for iced coffee?
No, if you are brewing hot over ice, because the melting ice dilutes it. The usual approach is to count the ice as part of the water: brew at your normal ratio but split the water, using about 60% as brew water and putting the other 40% in the carafe as ice. So a 1:16 brew with 25 g of coffee needing 400 g of water becomes 240 g poured hot over 160 g of ice. Cold brew is a different thing entirely — a concentrate at 1:8 that you dilute at serving time.
Does the grind matter more than the ratio?
They do different jobs, and grind is the one people have less control over. The ratio is trivially adjustable and exact. Grind is limited by the machine — a blade grinder produces particles of every size at once, so part of the coffee over-extracts while the rest under-extracts, and no ratio fixes that. If you are choosing where to spend, a burr grinder changes the cup more than the beans do. Once the grind is even, the ratio becomes the dial that actually responds predictably to being turned.