Brewing coffee at home can be incredibly rewarding—but it can also lead to disappointment if a few key factors are overlooked. Many people unknowingly make mistakes that result in sour, bitter, or flat-tasting coffee. The good news? Most of these issues are easy to fix with small adjustments.
In this article, you’ll discover the most common coffee brewing mistakes and how to correct them to ensure a consistently delicious cup.
1. Using the Wrong Grind Size
Why it matters: Grind size directly affects extraction. Too fine or too coarse, and your coffee won’t taste right.
- Too fine: Over-extraction, bitterness, and harsh flavor
- Too coarse: Under-extraction, sourness, and weak taste
How to fix it:
- Match your grind to your brewing method:
- Espresso: Fine
- Drip coffee: Medium
- French press: Coarse
- Pour-over: Medium-fine
- Cold brew: Extra coarse
- Use a burr grinder for consistent particle size
2. Not Using a Scale
Why it matters: Eyeballing coffee and water amounts often leads to inconsistent results.
How to fix it:
- Use a digital scale to weigh:
- Coffee: 1 gram per 15–18 grams of water
- Example: 20g of coffee for 300ml of water
- Adjust ratios to taste—but always measure for repeatability
3. Using Water That’s Too Hot (or Too Cold)
Why it matters: Water temperature affects how well coffee compounds are extracted.
- Too hot (above 96°C/205°F): Bitter, burnt flavors
- Too cold (below 90°C/195°F): Sour, under-extracted taste
How to fix it:
- Heat water to 90°C–96°C (195°F–205°F)
- If you don’t have a thermometer, boil water and wait 30 seconds before pouring
4. Using Old or Stale Coffee
Why it matters: Coffee loses its flavor quickly after roasting, and even faster after grinding.
How to fix it:
- Buy freshly roasted beans (use within 2–4 weeks)
- Grind just before brewing to preserve aroma and flavor
- Store beans in an airtight, opaque container in a cool, dry place
Avoid storing coffee in the fridge or freezer unless it’s vacuum-sealed.
5. Skipping the Bloom
Why it matters: Fresh coffee releases CO₂ when water is added. If not allowed to escape, it creates uneven extraction.
How to fix it:
- Pour a small amount of hot water over the grounds to saturate them evenly
- Wait 30–45 seconds before continuing to pour
- Especially important for pour-over, Chemex, and French press
6. Not Cleaning Your Equipment
Why it matters: Old coffee oils and residue can make your coffee taste bitter or rancid.
How to fix it:
- Rinse parts like carafes, filter baskets, and plungers after each use
- Deep clean equipment weekly with warm water and mild soap
- Descale machines monthly if you use hard water
7. Brewing Too Fast or Too Slow
Why it matters: Brew time affects extraction. Too short? Sour and weak. Too long? Bitter and overpowering.
How to fix it:
- Use a timer:
- Espresso: 25–30 seconds
- Pour-over: 2.5 to 4 minutes
- French press: 4 minutes
- Adjust your grind or pouring technique to speed up or slow down the process
8. Using Low-Quality Water
Why it matters: Coffee is 98% water. Bad water equals bad coffee.
How to fix it:
- Use filtered water for clean, balanced flavor
- Avoid distilled water (too few minerals) and heavily chlorinated tap water
If you notice off-flavors or a flat taste, your water might be the issue.
9. Using the Wrong Coffee-to-Water Ratio
Why it matters: Too much or too little coffee affects strength and flavor balance.
How to fix it:
- Start with a 1:15 ratio (1g coffee to 15g water)
- Adjust to 1:16 or 1:17 if the brew is too strong
- Use a scale for accuracy rather than scoops or spoons
10. Not Preheating Your Equipment
Why it matters: Cold equipment can lower brew temperature and affect extraction.
How to fix it:
- Preheat your mug, French press, or dripper with hot water before brewing
- This helps keep your coffee at the ideal temperature during the process
11. Using the Wrong Roast for Your Taste or Method
Why it matters: Roast levels influence how a coffee tastes and how it behaves during brewing.
How to fix it:
- If your coffee is too sour, try a darker roast
- If it’s too bitter, try a lighter roast
- Match the roast to the method:
- Espresso: Medium to dark
- Pour-over: Light to medium
- Cold brew: Medium-dark to dark
12. Ignoring Your Taste Preferences
Why it matters: Coffee is personal. What works for one person may not work for you.
How to fix it:
- Try different origins, roast levels, and brew methods
- Take notes on what you like (e.g., fruity, nutty, bold, smooth)
- Don’t be afraid to experiment until you find your favorite cup
Final Thoughts: Master Your Brew with Small Tweaks
Great coffee isn’t just about expensive gear or exotic beans—it’s about avoiding small, easy-to-make mistakes. By dialing in your grind size, water temperature, ratio, and timing, you can dramatically improve your home brewing experience.
Start with one change at a time and pay attention to how it affects the flavor. With consistency and a little curiosity, you’ll be brewing café-quality coffee in your own kitchen.