THE FOSTER BREW GUIDES
Coffee brew guides & ratios
Brew better coffee with Foster’s Kalita Wave 185 pour-over recipe, a home drip coffee maker calculator, and commercial batch recipes for Curtis and Fetco brewers.
A LITTLE MORE HANDS ON
Kalita Wave 185 pour over
A flat-bottom brewer, a few thoughtful pours, and a cup made just for you. A scale is needed for this recipe.
Coffee : water ratio 1:16.9
Starting brew time: 3:00
Water amounts are what you pour into the brewer. Some water stays in the grounds, so the finished drink will be smaller.
See both recipes
| Size | Coffee | Water added |
|---|---|---|
| 12 oz | 21 g | 355 g |
| 16 oz | 26.5 g | 450 g |
Your brew timer
Includes the bloom and final drawdown. Press Finish brew when the last water has drained.
Start both clocks as the first bloom water touches the grounds.
Let’s make your pour over
Get everything ready
You’ll need a Kalita Wave 185 and matching filter, a server or mug, a grinder, a gram scale, a timer, and a kettle—ideally a gooseneck. Use fresh, good-tasting water.
Rinse and warm
Fit the filter so its base touches the bottom of the brewer. Rinse with hot water to warm the brewer and server, then discard the rinse water.
Grind, level, and tare
Weigh your coffee and grind immediately before brewing. Start medium-fine, then adjust to taste. Add the grounds, gently level the bed, place the setup on your scale, and tare to zero.
Bloom for 30 seconds
Start your timer as you pour. Gently wet all the grounds, using 65 g. Stop pouring and wait until total brew time reaches 0:30. This first pour counts toward your total water. The bloom countdown ends while the total brew clock continues.
Pour slowly, in small rounds
At 0:30, pour until the scale reads 100 g. Pause, then continue in roughly 50 g additions. Keep a gentle, small circular pour over the coffee. Pour again as the water level falls; don’t let the bed drain completely between pours.
Cumulative scale targets: 65 → 100 → 150 → 200 → 250 → 300 → 355 g
Finish, drain, and enjoy
Near the end, gently wash grounds clinging to the sides back into the bed, staying inside the filter. Stop at 355 g. Let the remaining water draw down, remove the brewer, and gently swirl the coffee before serving.
Brew time, grind size & pour flow
Foster’s starting preference is about 3:00 total for a 12 oz recipe and 3:30 for 16 oz, including the 30-second bloom and final drawdown. These are starting points, not pass/fail targets for every coffee. Taste first. If a brew drains quickly and tastes sour or thin, try a slightly finer grind; if it drains slowly and tastes drying, try a slightly coarser grind. Change one variable at a time.
Your pouring speed changes the water level, agitation, and total brew time. Keep your flow consistent when comparing grind settings. On bar, Foster uses gooseneck kettles with flow restrictors to help avoid pouring too fast. Start with a gentle, controlled stream at home.
Want to get more technical? Compatible Acaia Pearl scales and Acaia apps can help you inspect or practice pour flow. Features depend on the scale model and app; check compatibility before choosing a setup.
YOUR EVERYDAY GO TO
Home coffee maker
Choose the markings on your home drip coffee pot, then measure with a scale or level tablespoons. This calculator assumes each marked cup holds 6 fl oz; check your machine before using it.
Coffee : water ratio 1:21.8
Pot-mark presets between the measured recipes are estimates. The 12-cup / 80 g recipe extends the last measured step by 5 g per additional actual cup. Treat it as a starting point and adjust to your coffee and machine.
Use level US tablespoons, not heaped scoops. We estimate 1 tablespoon ≈ 5 g; roast and grind change how much fits in a spoon. A scale is more consistent.
Your coffee maker’s “cup” may be smaller.
We often find that a coffee maker’s labeled cup holds 6 fl oz, rather than a standard US measuring cup’s 8 fl oz. Markings vary by machine—check yours before brewing.
Your selected pot marking contains 6 actual US measuring cups (8 fl oz each).
Check your coffee maker’s cup size
Pour 1 actual US measuring cup (8 fl oz) of water into the empty carafe and see where it lands on the markings. If it reaches about 1⅓ maker cups, each maker cup is 6 fl oz. A 6 fl oz maker cup is ¾ of an actual 8 fl oz cup. Follow your machine’s maximum fill line.
Why a full pot can taste weak
It’s easy to underestimate coffee when eyeballing a large batch. Too little coffee for the water produces a weak cup; uneven saturation or brewing problems can also leave the flavor under-extracted. Weighing your dose helps you repeat the result. Weakness and under-extraction are different, so taste as well as strength matters.
A home basket has limits. Grounds swell during the bloom and brewing, so an overfilled basket can overflow and send grounds into the carafe. Follow your brewer’s maximum coffee dose and fill lines. If the dose you want does not fit with room to expand and drain, brew two smaller batches instead of packing in more grounds.
Good coffee, without the guesswork
Measure your water
Fill to your selected coffee pot marking only after checking its cup size. These presets assume 6 fl oz per marked cup. For a 12-cup pot, that is 72 fl oz, or 9 actual US measuring cups. Stay below the machine’s maximum fill line.
Measure and grind your coffee
Use the coffee amount shown in your recipe. A medium grind is a good starting point for most home drip machines. Grind just before brewing when you can.
Set up and brew
Place the correct filter in a clean basket, add your grounds, and gently level them. Make sure the empty carafe is in place, then start the full brewing cycle.
Stir and enjoy
Let the cycle finish and the basket drain. Gently stir or swirl the finished coffee to even out its strength before serving. For longer holding, transfer to a thermal carafe.
Our home-brewer recipe chart
| 8 fl oz cups | Coffee | Approx. level tbsp | 6 fl oz maker marks |
|---|---|---|---|
| 3 | 40 g | 8 | 4 |
| 4 | 55 g | 11 | 5⅓ |
| 5 | 60 g | 12 | 6⅔ |
| 6 | 65 g | 13 | 8 |
| 7 | 70 g | 14 | 9⅓ |
| 8 | 75 g | 15 | 10⅔ |
| 9* | 80 g | 16 | 12 |
*9 actual cups / 12 maker cups is an estimated extension of Foster’s measured chart. A larger ratio denominator means less coffee per gram of water; these home recipes become lighter as batch size increases.
BREWING FOR A CROWD
Commercial batch brewers
For professional equipment such as Curtis or Fetco. Start with our batch recipes, then dial in for your coffee, grinder, and brewer.
Coffee : water ratio 1:15.0
The ½-gallon and 1-gallon doses are separate Foster starting recipes. The 1½-gallon dose scales the 220 g gallon recipe by 1.5. Confirm actual water delivery and basket and server capacity before brewing.
| Choose your batch | Coffee |
|---|---|
| ½ US gal | 126 g |
| 1 US gal | 220 g |
| 1½ US gal | 330 g |
A consistent batch, every time
Prepare the brewer and server
Start with a clean, empty server in position. Fit the correct filter to the basket, lightly rinse it, and let any rinse water drain. Confirm the brewer is ready and at temperature.
Weigh, grind, and level
Tare your container on a gram scale and weigh the dose for your batch. Use the grind setting dialed in for that coffee and equipment. Grind, add to the filter, and gently level the bed.
Select the matching batch
Insert the brew basket and select the batch size that matches your weighed coffee. If you choose the wrong batch, cancel promptly and follow your brewer’s instructions before restarting.
Let the cycle finish
Wait for the full brew and drip cycle to finish before removing the basket. Discard the used filter and grounds, then serve. Rinse an emptied server before making the next batch.
Keep your equipment clean
Follow your brewer, server, and cleaner manufacturers’ directions for cleaning products, dosage, contact time, and rinsing. A regular cleaning routine keeps old coffee oils out of the next batch.
Make the next cup even better.
Start with the recipe, taste, then change one thing at a time.
Sour or sharp?
Try a slightly finer grind. Check that your water is hot enough and the grounds are evenly saturated.
Bitter or drying?
Try a slightly coarser grind and make sure the brewer and filter are draining freely. Clean equipment helps, too.
Too light or too strong?
Keep your water amount steady and adjust the coffee dose a little. Note what you changed so you can repeat your favorite cup.
How to choose a coffee-to-water ratio
Brew ratios compare dry coffee mass with the mass of water added. A 1:17 ratio means 1 g of coffee for every 17 g of water. At the same extraction, 1:15 generally makes a more concentrated brew than 1:20. Ratio describes the recipe—not a measured strength or extraction result. Grind, water temperature, flow, contact time, and the coffee itself also shape the cup.
For these calculators, grams of water are approximated from US liquid volume: 1 fl oz ≈ 29.57 g, 1 actual cup = 8 fl oz, and 1 US gallon = 128 fl oz. Ratio uses water added, not the smaller amount of coffee collected after the grounds retain water. Tablespoon estimates assume about 5 g of ground coffee per level US tablespoon.
Foster’s brew ratios, compared
- Kalita Wave 185: 21 g / 355 g is 1:16.9; 26.5 g / 450 g is 1:17.0.
- Home drip: 4 marked cups (24 fl oz) / 40 g is 1:17.7. The estimated 12-marked-cup batch (72 fl oz) / 80 g is 1:26.6—a lighter recipe, not the same strength scaled up.
- Commercial: ½ gallon / 126 g is 1:15.0; 1 gallon / 220 g and 1½ gallons / 330 g are both about 1:17.2.
Coffee brewing questions
How much coffee for a 12-cup coffee maker?
If each pot marking is 6 fl oz, 12 marked cups is 72 fl oz (9 actual 8 fl oz cups). Our estimated starting dose is 80 g, or approximately 16 level US tablespoons. This extends Foster’s home chart and is lighter than our pour-over recipe. Confirm the carafe markings and basket capacity; split into smaller batches if the basket cannot accommodate your preferred dose.
How long should a Kalita Wave 185 brew take?
Foster starts around 3 minutes for 12 oz and 3 minutes 30 seconds for 16 oz, measured from the first bloom pour through the final drawdown. Use the 30-second bloom within that total. Taste decides whether a change is helpful; time alone cannot tell you whether a coffee is extracted well.
How much coffee for a 1.5-gallon commercial batch?
Start with 330 g of coffee for 1½ US gallons of programmed water, scaling our 220 g per gallon recipe. Verify the actual batch volume, use the matching brew program, and check basket and server capacity. Curtis and Fetco models and programs vary, so a recipe needs to be dialed in on your equipment.
Is weak coffee always under-extracted?
No. Strength is concentration; extraction is how much material the water removes from the grounds. Too little coffee for the water can taste weak even with reasonable extraction. Sourness, bitterness, dryness, sweetness, and brew consistency give you more information. Change dose to explore concentration and grind or flow to explore extraction, one variable at a time.