However, one of the less discussed points is the material used to construct the dripper. While many people assume this isn’t of major importance, it actually does have an impact on how your coffee extracts.
To find out how dripper material affects your brew, I spoke to a few specialists. Read on to find out what they had to say.
Lee este artículo en español ¿Cómo el Material Del Cono de Goteo Afecta el Sabor de tu Café?
Which Variables Affect The Pour Over Process?
Pour over coffee is a percolation brewing method where hot water is poured over coffee grounds and filters through them into a vessel. As the water passes through the coffee grounds, it extracts soluble flavour compounds in the coffee.
However, the filter (often paper, but can also be mesh or cloth) prevents oils and sediment from passing through, generally resulting in a lighter and cleaner cup.
Oils, acids, and carbohydrates (among many other flavour compounds) contribute to the final taste and aroma of a cup. Their development and extraction depend on a number of different variables, including your brew ratio, brew time, water temperature, and the material of both your filter and your dripper.
By adjusting these elements and other conditions under which the coffee extracts, you can end up with a different cup even when using the same beans. For example, if a coffee brews for longer, it will naturally spend more time interacting with the coffee grounds and therefore extract more flavour compounds. Similarly, if the brewing temperature increases, it will increase solubility and extraction.
You may also like How To Take Your Pour Over Brewing To The Next Level
Dripper Material & Brewing Temperature
Water temperature is recognised as an important factor that affects extraction. Different dripper materials retain less or more heat during brewing, and therefore will affect your cup.
Jonathan Gagné is an astrophysics expert and coffee enthusiast from Montréal, Canada. He runs a blog called Coffee ad Astra and is launching a book on the physics of filter coffee later this year.
He tells me that a dripper’s material impacts its heat retention during extraction. Different materials have different “thermal masses” and levels of insulation, meaning that they conduct and retain heat differently.
The key factor here is the “thermal mass”, which is a figure that determines how much heat a material must absorb before its temperature rises. For example, concrete and stone have to absorb a lot of heat energy before they start to increase in temperature. They have a high thermal mass.
However, materials like wood and straw have low thermal masses, meaning they increase in temperature much more quickly (and in some cases, catch fire).
Jonathan says that plastic and stainless steel drippers have lower thermal masses than other materials and weigh less. This means that they heat up more quickly, and ultimately “steal” less heat from the brew. Conversely, materials like glass and ceramic have take longer to reach the same point, ultimately taking more heat away from your coffee.
However, Jonathan adds that insulation (heat retention) is also important. “Ceramic, glass, and stainless steel are all bad at thermal insulation, so they will transfer some of their heat to the surrounding air, and then steal more heat from the brew to reach equilibrium again,” he explains. “Ultimately, there are only a few materials that have a low thermal mass and good thermal insulation.”
Arnout de la Rambelje manages sales at Moccamaster. He tells me that the Moccamaster is popular in Europe where winter temperatures can plummet. This means that users tend to want to keep their brewing temperature high.
The Moccamaster’s filter holders have been made from polypropylene since 1994. Arnout tells me that the holders consist of two plastic layers (flat and ribbed) that form an “airbag” between the coffee filter and its holder. He says that this offers superior heat retention.
This means that in winter, when temperatures drop, the Moccamaster’s polypropylene holders keep a stable temperature throughout extraction, which improves consistency and ultimately improves final cup quality.
Temperature’s Effect On Stability
Cauã Sperling is a barista, instructor, and the co-owner of Fora da Lei in São Paulo, Brazil. He tells me that he offers customers a choice of different drippers in his café.
However, Cauã says he aims for consistency and a “thermal balance” across drippers. He explains that a thermal balance is when “a brewing system’s elements stop interacting with each other and extraction stabilises… it’s what we seek in manual brewing”.
Jonathan agrees that thermal insulation helps with stability. “A better insulating material will stabilise your temperature from the start to the end of the brew.
“Even if you lower the kettle temperature and use a high insulation dripper, you might get a different cup profile compared to what you get with a higher kettle temperature and a dripper with low insulation.”
Cauã says that this also ensures a repeatable result. “It’s easier to repeat a coffee recipe in a stable dripper.
“At the end of the day, [it’s about] what demands less effort from me and allows me to brew coffee the same way over and over again.”
This doesn’t mean, however, that a non-plastic dripper will guarantee poor results. Heavy materials like glass and porcelain can be preheated to keep them from drawing heat from the brew.
Stainless steel and copper can also be preheated, but as they dissipate heat quickly into the environment, they should be preheated just seconds before use.
Cauã says: “Plastic drippers provide a more stable temperature with less effort. Glass and ceramics are nearly the same and demand more energy to heat up.
“When this happens, I adjust the brewing, and my first pour tends to happen at a lower temperature.”
Jonathan adds that “with more experience” and “better control of variables”, he notices that different materials produce a vastly different cup profile.
“Some materials like glass or ceramic produce a weaker and more sour cup compared to plastic,” he adds. This is because lower heat retention results in a lower brew temperature throughout, which highlights acidity while reducing sweetness and body.
Which Dripper Material Is For You?
While some dripper materials might keep your brew stable and change the extraction, you also need to keep in mind some more practical concerns.
For example, your dripper’s life span matters. Is it easy to bend, damage, or break? If you only use it in your kitchen, this might not be an issue. If you plan on travelling with it, it might.
How susceptible is the material to high temperatures and chemical agents? Will it absorb the residual acids from your coffee and cleaning products over time? Acrylic drippers are light and have a clean design, meaning they can be used frequently, but they are more susceptible to stains.
Finally, of course, there’s cost. Polypropylene and resin acrylic drippers are affordable, but they have a shorter life span. Ceramic and copper last longer, but cost more.
For those getting started with pour over coffee, a polypropylene dripper is a good all-round option. Cauã says: “It’s the best cost-effective dripper. It requires less control from and there’s less interference from your brewing variables. You don’t need to use a lot of hot water to preheat it compared to a ceramic dripper.”
Jonathan agrees. He says: “Currently, my favourite dripper is the Fellow Stagg [X]. It has a vacuum-insulated double wall, which I find produces sweeter, juicier cups.
“Another good choice is the plastic Hario V60, especially if you want to recreate experiences and recipes from the internet, because it’s more widely used.”
The bottom line is simple: dripper material affects the temperature of your brew, which in turn affects extraction and changes your cup profile.
When choosing a dripper, however, you should remember that temperature is just one factor. Ask yourself if you want to experiment, or if you want something easy and consistent. Furthermore, your lifestyle, skill level, and budget will all come into play. Glass drippers won’t suit people who brew lots of coffee on the go, for example.
Consider these factors when deciding which material to go for, and finally, think about repeatability. Materials with a low thermal mass, like plastic, will mean you can easily replicate the same brew, while glass and ceramic are more susceptible to under-extraction and producing a more acidic brew.
Enjoyed this? Then read “100% Arabica”: What Does It Mean?
Photo credits: Ana Paula Rosas, Jonathan Gagné, Moccamaster, Noé Aubin-Cadot
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