Maxing out the potential of coffee involves the right roast, grind, brewing style, water temperature, and other factors you may not be doing correctly, or even considering.

Coffee doesn’t just feel like a magical elixir that reinvigorates your body, mind, and soul – reams of research show that it actually does those things to some extent. You just have to brew it right, and that has nothing to do with half-caf, double-hot, no-foam, or any other of the hyphenated adjectives baristas yell out. Not to worry; we consulted experts on how to prepare the single healthiest cup, and they were willing to spill the beans.

The Healthiest Coffee Bean

According to science, there’s practically nothing coffee can’t do. It’s been associated with a reduced risk of liver cancer, in a review published in May 2017 in BMJ Open; a reduced risk of colon cancer in women who drank more than three cups a day, in an analysis published in the July 2018 International Journal of Cancer; as well as a reduced risk of type 2 diabetes and even stroke.

A large prospective cohort study published in May 2022 in Annals of Internal Medicine, which looked at data from more than 171,000 people, found that those who drank between one and a half and three cups of sweetened or unsweetened coffee per day had a roughly 30 percent lower risk of death than non-coffee-drinkers. The lowest risk was found to be among those who downed roughly three cups of coffee a day.

Though caffeine itself has perks, including improved mental function and memory, the majority of coffee’s health benefits come from compounds called polyphenols in the beans. Polyphenols have been shown to support brain and digestive health and help protect against heart disease, diabetes, and some cancers, according to a review published in Frontiers in Nutrition in September 2018.

Since polyphenols are key to the greatest health benefits your coffee has to offer, you should aim to get the maximum amount of these compounds each day, says Bob Arnot, MD, the author of The Coffee Lover’s Diet and the former chief medical correspondent for NBC News. Some beans do a better job of this than others.

The highest-polyphenol coffees are those grown in high-altitude spots, such as Ethiopia and Central and South America, according to a review published in the journal Antioxidants. Dr. Arnot suggests looking for beans from the Huila region of Colombia, or those from Peru, Bolivia, Costa Rica, or Ethiopia. Arnot tends to find 19,000 milligrams (mg) of polyphenols per cup of coffee if he uses beans from East Africa; those from major national chains have as few as 2,500 mg per cup. The goal is to get at least 650 mg of polyphenols daily, but the more you ingest, the better.

The roast also matters. Roasting beans deepens their flavour, but the heat also breaks down healthful compounds like antioxidants and polyphenols. So light roasts (which are also denser and therefore have slightly more caffeine per scoop than dark roasts) tend to be higher in antioxidants, says Ali Redmond, the founder of Coffee Belly. Light roasts also contain higher concentrations of chlorogenic acid, a compound found in coffee that has been shown to help protect the body against inflammation and cell damage, according to a study published in June 2017 in the Journal of Medicinal Food.

The Healthiest Way to Brew Coffee

After selecting the best beans, the next step is to grind them. Coffee aficionados say you get the best flavour when you grind just before brewing, because otherwise the contact with the air causes oxidation that degrades flavour over time. But pre-ground coffee isn’t any less healthy for you.

The main benefit of grinding the beans yourself is controlling how finely you grind them, and that does affect the number of health-promoting compounds in your cup.

When it comes to brewing, the goal is to extract the most polyphenols from the beans, and the finer the grind, the more polyphenols you’ll get.

This means that espresso, which requires a very finely ground bean, is one of the healthiest choices.

If the flavour of espresso is too strong, you can use a pour-over method, which also uses a fairly fine grind. Pour-over coffee involves an inexpensive device and a filter, which can have cardiovascular benefits, according to a study published in April 2020 in the European Journal of Preventive Cardiology.

In examining the data on more than 46,300 people over a 20-year span, researchers found that people who drank filtered coffee had lower rates of death from cardiovascular disease than both unfiltered coffee drinkers and non-coffee-drinkers.

This could be because coffee brewed without a filter contains as much as 30 times more cholesterol-raising compounds than filtered coffee.

The last component in brewing the healthiest cup of coffee is the water temperature. Ideally, it should be just below boiling (between 195 to 205 degrees F) for optimal extraction, says Chris Clark, the founder of Brew Coffee at Home. If it’s colder, you’ll have underextracted coffee (you won’t get all those key nutrients), while if it’s too hot, the flavour will taste burned. Don’t have a thermometer? Wait 30 seconds after the water boils to pour, and the temperature should be perfect.

Fans of cold brew may be wondering if this means they’re not getting as many health benefits per cup. “With cold brew, you’re trading temperature for time,” says Arnot. In cold brewing, coffee grounds typically get soaked at room temperature for 24 hours, leading to a slower extraction process.

Arnot’s research has found that a cup of cold brew has 80 percent of the healthy compounds of traditionally brewed coffee, which is less but still pretty good.

And as a bonus, cold brew’s slower extraction process tends to temper the acidity and bitterness of the brew, which means you may not need to add as much milk, cream, or sugar to enjoy it. Cold brew also lasts longer, because the compounds that contribute to a stale flavour develop more slowly in cool temperatures, Arnot says. If you’re making cold brew yourself, you can control how strong it is, but be aware that many commercially available products are cold brew concentrates, intended to be diluted with water or milk. If you don’t dilute these, you could be consuming more caffeine than you realise.

Of course, if you want to cool off without losing any of the polyphenols in your cup, you can try iced coffee, which is made by serving traditionally brewed coffee (typically very strong coffee to counter the diluting effect of the ice) over ice.

There is also a Japanese method known as flash brewing in which concentrated hot coffee is poured directly into ice. Because most of the extraction occurs in the first few pours of hot water, these methods tend to retain most of their healthy compounds, but are still cool and refreshing on a hot day.

Of course, if all this sounds like a lot of work, and you’re not a coffee snob, you can always stir up some instant coffee. A study published in July 2017 in the Journal of Food Science and Technology found that instant coffee yielded the highest antioxidant concentration compared with espresso, filtered coffee, and Turkish or Greek coffee brews.

The Healthiest Way to Serve Coffee

After going to all that trouble to brew the perfect cup, you don’t want to offset all those perks by adding cream and sugar. The healthiest way to drink your coffee is black, and if you start with a flavourful, high-quality bean, you shouldn’t need to add anything. “The reason people started putting milk in coffee during World War II is because they were drinking terrible coffee,” Arnot says. “If you’re adding sugar or milk or fat to the beverage, it isn’t as healthy as having nothing in it.”

Make Your Coffee Healthier

So, there you have it. The absolute healthiest cup of coffee uses high-altitude beans, a lighter roast, a fine grind, a filter, hot but not boiling water, and is served black. Most of the health benefits that have been studied resulted when people drank four to five 8-ounce cups of coffee daily, Arnot says. That amount does fall within the U.S. Food and Drug Administration’s (FDA) recommended limit for daily caffeine intake (around 400 mg), but if you use these guidelines to prepare your brew in the healthiest way, you can pack more polyphenols into a single cup and get the same benefits by drinking less. And if you’re sensitive to caffeine, don’t worry: Decaf coffee has a similar roster of benefits.

Additional reporting by Jill Waldbieser.