Ratio Six Series 2 Coffee Maker

Before first use, run a water-only brew cycle to flush and prime the machine. Fill the removable Tritan water tank (44oz / 1.3L maximum), place a flat-bottom filter in the basket, position the carafe, and press the start button. Discard the rinse water.

The Ratio Six Series 2 is SCA Gold Cup certified — it brews at 195–203°F and meets the Specialty Coffee Association's standards for extraction yield and brew time. The 1400W heating element, borosilicate glass water lines, and precision shower head work together to deliver even saturation across the coffee bed.

The Series 2 thermal carafe has been redesigned with no moving parts, a more pronounced pour spout, and a wide opening large enough to fit your hand inside for thorough cleaning. It auto-seals when set down, keeping coffee hot for 30–45 minutes without a hot plate.

The heat shield is included and wraps around the showerhead area during brewing — it keeps the brewing environment at ideal temperature, particularly important for full 8-cup batches. Always use the heat shield when brewing.

Filters: Use standard 8–12 cup flat-bottom basket paper filters. The Able Basket reusable metal filter is also compatible.

Three-Phase Brew Cycle

The Ratio Six automatically runs three phases after you press start: Bloom (brief initial burst of hot water to wet and expand the grounds), Brew (the main water delivery through the precision shower head), and Ready (machine signals brewing is complete). Total brew time for a full 8-cup (40oz) batch is approximately 6–8 minutes.

Dose and Ratio

Use 1:15–1:17 coffee to water by weight. The tank holds 44oz of water, which yields approximately 40oz of brewed coffee (roughly 10% is absorbed by grounds). For a full pot, use 70–80g of medium-ground coffee. For smaller batches (2–4 cups), scale proportionally — the Six performs equally well at any batch size within its range.

Grind

Use a medium grind — roughly the texture of granulated sugar, coarser than espresso but finer than French press. For freshly roasted coffee, a medium-coarse grind works well. Adjust based on taste: if the cup is sour, grind finer; if bitter, grind coarser.

Heat Shield

Always use the optional heat shield for maximum extraction temperature and flavor. Clip it around the showerhead before brewing — it encloses the spray arm during brewing, which keeps the coffee bed temperature within the ideal SCA range. Removing it lowers brewing temperature slightly.

Carafe and Serving

The Series 2 auto-sealing thermal carafe keeps coffee hot for 30–45 minutes without any burning or flavor degradation from a hot plate. The wide mouth opening (large enough for a hand) makes cleaning straightforward. Do not put the carafe in the dishwasher — hand-wash only.

Water Tank

The tank sits separately from the machine on its own base, so you can fill it at the sink and return it to the Ratio Six. Water markings go from 2 to 8 cups in 1-cup increments, accurate to within 1oz.

After Each Use

Remove and discard the paper filter. Rinse the basket under hot water. Hand-wash the thermal carafe with mild dish soap — the wide opening makes this easy. Rinse thoroughly. Do not put the carafe in the dishwasher.

Monthly — Descaling

Descale when you notice mineral buildup on internal water lines or slower brew times. Use a citric acid-based descaler — follow the manufacturer's instructions, typically one cycle with the descaling solution followed by 2–3 fresh water rinse cycles. Do not use vinegar.

Water Tank

Rinse the Tritan water tank weekly. Hand-wash only — do not put in dishwasher.

Heat Shield

Wipe the heat shield with a damp cloth periodically. It can be removed for cleaning by unclipping it from the showerhead area.

Brew Running Slowly / Filter Overflowing

Grind too fine — the flat-bottom basket fills up if flow is restricted. Adjust to a coarser grind. Also check that the filter is fully seated flat in the basket.

Coffee Tastes Weak

Increase dose, grind finer, or use the heat shield if you aren't already — it raises extraction temperature noticeably.

Carafe Not Sealing / Coffee Dripping

The Series 2 carafe auto-seals when placed on a flat surface. Ensure the carafe is fully seated on the drip platform and positioned directly under the brew basket opening.

Machine Not Starting

Ensure the water tank is properly seated and filled. Confirm the basket and carafe are correctly in place.

Warranty and Support

Ratio products carry a 1-year limited warranty. For support, visit help.ratiocoffee.com. Seattle Coffee Gear also supports Ratio products purchased through seattlecoffeegear.com.