• Sour siphon coffee is a sign of under-extraction, meaning the water didn't pull enough flavor from the grounds.
• The most common fix is to grind your coffee finer, which increases surface area and extraction.
• Check your brew time: siphon coffee should steep for 60-90 seconds after the water rises to the top chamber.
• Water temperature matters—aim for 195-205°F (90-96°C), which is just below boiling.
• Adjust your coffee-to-water ratio: starting with 1:15 (coffee to water) gives a balanced cup.