Are you using a Hario brewer? Here is a quick brew guide:

• Boil water and let it sit
• Temperature must be lower than 95 °C, above 90°C, but play to see how you like it, some go as low as 80.
• Take the filter and place in Brewer. Poor water slowly all over the filter paper so that it is wet.
• Pour out that water
• Add fresh ground coffee to filter (use about 8grams of coffee per 150ml of water but you can use more or less for taste or body).
• Pour water over the coffee added to the brewer but only just cover the coffee, wait for the blooming of the coffee and water pre-brew (should happen within 40 seconds)
• Slowly add the rest of the water so that at no time the coffee and water combo over flow to touch the filter paper. The water must also be poured on to the coffee not the paper.
• When the water is taking too long to drain then I normally stop, others go on, but for me this is when over extraction occurs

Enjoy a fresh brew.