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Estimated reading time: 8 minutes
Quick Answer
The easiest ways to brew better filter coffee at home are to keep your equipment clean, remove excess chaff from your grounds, and sort defective coffee beans before brewing. These small habits can improve sweetness, clarity and consistency in the cup without requiring expensive equipment.
When talking about how to brew better filter coffee, conversation usually gravitates towards the bigger and more exciting variables: equipment, grind size, drippers and recipes. These all contribute enormously to the final cup. However, there are also small habits that can dramatically improve coffee quality while flying under the radar for novice brewers.
Here are 3 simple habits to add to your brewing routine to help your filter coffee taste cleaner, sweeter and more consistent.
1. Keep it Clean
This feels redundant to say, but keeping your coffee equipment clean is often overlooked, and even professionals don't always get it right. Even with the best brewing technique, beans and equipment, poor cleaning habits will quickly ruin your filter coffee.
Proper equipment cleaning deserves its own guide in the future, but I’ve put together a general run-down below, with a recommended frequency based on brewing 2–3 coffees per day.
Cleaning Frequency Guide
| Frequency | What to Clean |
|---|---|
| Monthly | • Full grinder clean - burr chamber, burrs, exit chute • De-scale espresso machine • De-scale kettles |
| Weekly | • Backflush espresso machine grouphead with cafiza/pulycaff powder • Steam wand deep clean - remove steam tip & soak |
| Daily | • Backflush espresso machine with water only, no chemicals |
| Between Uses | • Pour-over drippers, carafes and cups • Purge espresso machine group head and steam wand before and after using • Wipe steam wand • Purge the grinder if it has a lot of retention |
Moka Pots
To address the elephant in the room, yes, you should be cleaning your moka pot with dish soap and hot water. If it is gentle enough to hand-wash with, then it is gentle enough to use on the moka. You don’t need to ‘season’ it, it isn’t a cast iron skillet.
Allowing residue to build up only introduces stale, unpleasant flavours. Soap, hot water, allow it to dry fully before reassembling.
Final Thoughts on Cleaning
Cleaning coffee equipment is about regular, gentle maintenance rather than waiting for residue to build up and then attacking it with chemicals and detergents.
Even if you’re already chemically backflushing your machine regularly, purging your espresso machine and grinder helps keep your shots tasting great between these cleaning cycles.
When you do use detergent or soap to clean your coffee equipment, remember to rinse thoroughly with hot water. While not harmful to ingest, the taste of soap is not desirable and is a surefire way to completely ruin your brew.
2. Chaff Removal
When grinding coffee for filter brewing, you might notice a flaky, papery material in the grounds. You may find flecks throughout the dose or stuck to the grinder's exit chute due to static. This is chaff, also known as silverskin.
If static is a consistent problem for your grinder, our guide on why RDT reduces static in coffee grinding explains why a tiny amount of water can reduce retention and mess.
Chaff is a cellulose material that forms around the bean as it grows. Most of it is removed during roasting as the bean expands and sheds the chaff. However, some silverskin remains in the little fold of the coffee bean.
While chaff is not the most detrimental thing in the world for brewing, it can still contribute negative flavours and textures that you may want to avoid. Chaff tastes papery and astringent, with an unpleasantly mouth-drying quality.
Brewing filter coffee with even a moderately significant amount of chaff in the grounds can increase astringency and reduce desirable characteristics such as sweetness and clarity.
Professional Tip: Lightly roasted washed coffees tend to benefit the most from chaff removal because their delicate florals, acidity and clarity are more easily masked by papery astringency.
Double grinding can help release larger flakes of silverskin before the final brew grind.
Method & Best Practices
The easiest way to remove coffee chaff is to blow it out of the ground dose before brewing.
- For smaller doses, you can remove the chaff with the grounds still in the catch cup.
- For medium and larger filter coffee doses, it can help to spread the grounds onto a plate or coffee sample tray.
- Sometimes chaff will stick to the sides of the catch cup due to static.
Removing chaff is inevitably a little messy, so be prepared to sweep up small amounts afterwards. I would recommend blowing chaff over the kitchen sink to minimise mess.
Bonus Chaff Removal Tips
Lens Blower
Utilise an air blower typically found in camera lens/sensor cleaning kits. They can be bought separately for very cheap and are very efficient and precise at blowing out chaff, as well as being useful when cleaning your grinders.
The Double Grind
By grinding coffee in two stages, you can remove chaff much more efficiently.
Start by grinding at a very coarse setting — much coarser than what you’d normally use for filter brewing, approximately 60 Comandante clicks. This produces larger coffee pieces, allowing the chaff to release more easily as larger flakes that are easier to remove.
Once the chaff has been blown away, return your grinder to the target filter coffee grind size and grind again. You can also compare this with our guide to the best filter coffee grinders for home if you are trying to improve grind quality more broadly.
It is worth noting that double grinding will alter your particle-size distribution, most noticeably by reducing large boulders. Your second grind size may need to be adjusted to account for this.
Final Thoughts on Removing Chaff
While I personally prefer to remove chaff, it is definitely an optional step for most coffees.
Different coffees will be affected differently by the presence of chaff. Lightly roasted washed coffees with delicate flavour profiles will benefit the most from removing it.
Blowing chaff from the ground coffee dose before brewing at the Orea Big Boy Cup.
3. Bean Sorting
The quality of the beans you put into your brews has a direct impact on the quality of the cup, and that goes beyond simply buying higher quality coffee. You can browse Harmony's current selection of coffee beans here.
Coffee is an organic product and is therefore susceptible to inconsistencies and defects — even in the highest quality lots intended for competitions.
Defects to Look Out For
Below are some of the most common coffee defects you’ll find in a bag of roasted beans.
Quakers
“Quakers” are beans that come from underripe cherries and have insufficient sugars to develop in the roast.
They are noticeably lighter in colour and contribute vegetal, astringent, peanut or sesame flavours.
Scorched/Tipped Beans
‘Tipping’ caused by heat damage to the endosperm of the bean, or ‘scorching’ caused by too much heat from the hot metal parts of the roaster making contact with the beans both cause darker charred spots that contribute burnt flavours and bitterness.
Insect-Damaged Beans
If you find pin-prick tunnels bored into your coffee beans then that is an insect-damaged bean, most commonly caused by the coffee berry borer.
The damage to the cherry and bean allow contamination by mold and bacteria, which results in these beans tasting musty and sour.
Shells
Shells are a physical defect that look like, well, hollow sea shells.
They roast faster than the rest of the batch, making them taste slightly harsher and roastier.
Shell defects can roast faster than the rest of the batch and taste slightly harsher.
Chipped/Broken Beans
Either in the processing stage or the roasting stage beans can get damaged by machinery.
Beans broken before roasting share the same issues with shells — faster roasting due to greater surface area and smaller mass.
Small broken fragments can roast differently and are worth removing when they appear extreme.
Peaberries
Not so much a ‘defect’ than it is an ‘anomaly’.
Coffee beans grow in their cherries as a pair, which is why they have a flat side as well as a round side.
If a cherry forms with only one bean, then that bean will form slightly smaller and completely round on every side.
Peaberries are rounder than typical coffee beans and are not necessarily a defect.
Over-Sorting, Colour Variation & Bean Sorting Final Thoughts
I firmly believe it is possible to over-sort coffee in many situations.
Some batches of specialty coffee naturally contain colour variation due to processing and roasting differences. While it can be tempting to sort your coffee into one completely uniform colour, doing so can sometimes remove important flavour characteristics that contribute to the overall sensory experience.
Slightly darker beans may contribute sweetness and body, whereas lighter beans may contribute brightness and florality.
For home filter brewing, I would remove the extreme outliers while allowing for natural colour variation in between.
Bean sorting is enormously impactful because you can remove the beans that are preventing a good coffee from becoming a great coffee. Once sorted, make sure the coffee is properly rested too — our guide on resting coffee explains how to get the most out of your brews.
If you've gone to the effort of sorting defects and allowing your coffee to reach peak flavour, there's no need to rush through the bag before quality starts to decline. Freezing coffee can dramatically slow oxidation and preserve flavour for months. If you'd like to learn more, we've put together our ultimate guide to freezing coffee.
FAQs
How often should I clean my espresso machine?
Assuming you’re making only a couple of drinks a day, you should do a full backflush cycle weekly. Between drinks, make sure there’s no coffee left in the portafilter and flush the group head with hot water.
Should I clean my moka pot with soap?
Yes. Dish soap does not harm the metal, so you should use hot water and soap after every use. Don’t allow residue to build up, because stale coffee oils quickly create unpleasant flavours.
What is coffee chaff?
Chaff, also known as silverskin, is the papery cellulose layer that forms around the coffee bean as it grows inside the coffee cherry. While most of it is removed during roasting, small fragments can remain in the ground coffee and affect the final cup quality.
What does coffee chaff taste like?
Coffee chaff typically tastes dry, papery and astringent, with a straw-like flavour. Removing excess chaff before brewing filter coffee can help improve sweetness, clarity and mouthfeel.
What are coffee defects?
Coffee defects are abnormalities or damaged beans caused by natural mutations, insects, processing issues or roasting problems. Certain defects can contribute unpleasant flavours such as bitterness, ashiness, mustiness or harsh astringency.
How do I identify coffee defects?
It takes practice, but it becomes easy to notice them once you know what to look for. Quakers are usually much lighter than the rest of the roast, while tipping and scorching show up as small, dark marks on the surface of the bean.
How much sorting is too much sorting?
Colour variance is normal in coffee. Remove the damaged beans and anything at the extreme light or dark ends, but don’t feel the need to make every bean look identical.
Take your brewing game to the next level?
Espresso lovers can find our guide on the Best Coffee Tampers here.
Filter coffee lovers can find our guide on the Best Pourover Filter Coffee Recipes here.
Find some of the best free tools to accompany your brews.
Learn how to make the world's most incredible iced pourover.
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About the Author
Gage is a competition barista and was previously Head of Coffee for Sale Moon Coffee. He has spent a long time working with Harmony Coffee. He is a barista trainer, has trained many baristas, and has competed in countless coffee championships.
