The folks at Business Insider have sat down and definitively answered the most burning question in the world: Which cup of coffee is the strongest? If you like your information delivered in slow bits of text laid over images of hot liquid pouring from one container to another, you can watch the video below, or just read the summary below.

Espresso has more caffeine per ounce (61mg an ounce as opposed to 18mg in a whole cup of drip coffee) but diluting with water will cut down on the concentration.

Different beans have different caffeine content.

Robusta has some of the highest levels.

The roast also contributes to the level of caffeine that's extracted.

 The longer the roast, the more caffeine burns off.

Lighter beans are stronger than darker.

Finer grinds allow for more surface area to extract

The optimal brew temperature is between 195-205 degrees Fahrenheit.

 The longer the brew, the more caffeine.

So if you want a powerful cup of joe, you want a Double Espresso made with fine lightly roasted robusta beans with a long brew at about 200 degrees Fahrenheit. Presto.