CONE VS FLAT BOTTOM BASKET COFFEE FILTERS: IS ONE BETTER?

How does the shape of your coffee filter affect your morning brew? Science has the answer!

You already know that your choice of coffee beans, grind size, and brewing method influence the flavor of your coffee. But what about something as basic as the coffee filter shape? Does it have an impact?

Coffee aficionados have long debated this topic, and now we have an answer! So what have we learned about filter basket shapes, and how can we use it to brew better coffee? Keep reading to find out.

Does Shape Matter, And Why?

There are two types of filter basket shapes common to drip coffee machines, pour-over drippers, and other coffee brewer types: cone filters and flat-bottom basket filters. You may have noticed your coffee tasted slightly different depending on the shape of your brewer, but have you ever asked yourself why?

Recently, coffee scientists tackled that very question, and what they learned is fascinating (1).
The study was carried out at the UC Davis Coffee Center, the premier coffee research facility in the U.S., and sponsored by the Specialty Coffee Association (SCA) and Breville. They found that even inexperienced tasters noticed different coffees brewed with different filter baskets (2).

In fact, the only factor that tasters found more impactful than basket shape was the roast level of the coffee, which comes as no surprise.

Why The Shape Of The Filter Matters

So why does basket shape make such a difference in the profile of the brewed coffee? It’s all about water flow. I won’t get into the nitty gritty of fluid dynamics and mass transfer here, but suffice it to say that the geometry of the filter basket influences how the water flows through the bed of coffee grounds and, thus, how the coffee is extracted.

Cone Vs Basket Coffee Filters: What’s The Difference?

The result of the different extraction in the different shaped baskets can be quantified using a measurement known as Total Dissolved Solids (TDS). Without getting too technical, TDS measures the degree of extraction from the ground coffee. A higher TDS means the coffee is more fully extracted. It is essentially the amount of coffee in your coffee.

It has been found that flat filter baskets produce coffee with lower TDS than cone filters, all other factors (like pouring technique, water temperature, and grind size) being equal.

How Does It Affect Your Cup Of Coffee?

This is what you really came here for, right? Now that we know all this, how can we use it to brew better coffee?

Different TDS values highlight certain flavors in coffee, so you can choose a drip coffee maker with a filter basket shape according to which flavors you enjoy.

Generally speaking, the lower TDS from the flat baskets favors sweeter notes like fruits, honey, tea, and florals. The higher TDS from the cone filter baskets is better for bringing out darker and earthier flavors like umami, smoke, cocoa, and dried fruit.

For a detailed comparison, check out this video:

Other Ways To Play With Coffee Flavor

There are many ways to influence the flavor of your coffee aside from basket shape. For starters, the filter material – metal, paper, or cloth – also has a substantial impact, particularly on the body and mouthfeel of your coffee. 

By far, the biggest factor dictating the taste of your coffee is the type of coffee beans you buy. Varietal, origin, and roast level all play a huge role. Then there are different brewing methods, like immersion versus infusion techniques. You can also play with other aspects of coffee brewing, like grind size, water temperature, coffee-to-water ratio, and pouring technique. 

The Verdict

There is no right or wrong filter basket shape. One doesn’t brew better coffee than the other. But now we know for sure that there is a difference between cone and basket filters, so one may be better for your taste. If you love smokey and earthy flavors in your daily coffee, consider a conical basket. But if you prefer sweet and fruity flavors, opt for the flat basket.