Can you answer these questions on storing and preparing coffee?

You are also likely to fail to answer correctly if you are asked whether you should store your coffee in the freezer, whether you should grind your own beans to ensure fresh coffee, and what the most important factor is in keeping coffee fresh.

Most Have No Idea

Most Americans are clueless on the answers to these questions, say the makers of Roasting Plant Coffee, an operator of restaurants based in New York.

They say they know that ignorance on these issues is widespread because they conducted a survey of a thousand coffee-drinking millennials—they are the ones who should know—and discovered just how ignorant we all are on these topics.

The survey, the company says, disclosed major gaps in knowledge about how long to keep coffee, what makes coffee fresh, and where to store it.

Test Yourself

How about you? Are you better informed than the average coffee drinker?

Check out these answers to questions asked in the survey and how coffee drinkers responded:

Question: What is the biggest influence on the freshness of coffee?

Answer: How soon it is consumed after it has been roasted.

Response: Seven in every 10 coffee drinkers surveyed said they know what determines whether your cup of coffee is fresh. Only 24%, however, were aware that the biggest influence on coffee’s freshness is how soon it is prepared after the coffee has been roasted.

Question: How long can you store your coffee before it loses its freshness?

Answer: You can store your coffee for only 10 days before it loses its freshness. Studies conducted by The Zurich University of Applied Science and the Specialty Coffee Association found that the aroma and taste of coffee degrades by up to 70% in the first 10 days after the coffee is roasted.

Response: According to the survey, most people who make their coffee at home store it for three weeks or more; only one in every 10 keep it on the shelf for less than a week.

Question: Should you store your coffee in the freezer?

Answer: No. Moisture and freezing have negative effects on the molecular makeup of coffee and, as a result, harm its flavor. It is better stored in your cupboard.

Response: Four in every 10 of those who make their coffee at home store it in the freezer, according to the survey.

Question: Is it better to buy coffee that is already ground or to grind it yourself?

Answer: It is better to grind it yourself—if you want to preserve the flavor. And to drink it as soon as possible after you do so.

Grinding coffee causes it to degrade quickly as a result of the loss of carbon dioxide, which is called “off-gassing.”

The Zurich University researchers and the Specialty Coffee Association found that coffee “off-gases” almost completely within a few days or even within a few hours. Up to 70% of the carbon dioxide is released in the first day after it has been ground, causing the compounds in the coffee that give it its distinctive aroma and flavor to break down quickly.

Response: Three-fourths of the respondents buy ground coffee to make at home.

• The survey also found that most coffee drinkers have three devices at home to prepare their coffee. The top three are drip machines at 48%, pod machines at 46%, and grinders at 41%.

Elusive Search

Achieving the freshest coffee possible is elusive, explain experts at Roasting Plant Coffee. The reason is that coffee is continually and quickly undergoing physical and chemical changes. These changes cause coffee to lose its freshness and quality over time.

Even when moisture and oxygen are absent, coffee will lose its freshness, the experts say. The reason is that it is an inherently unstable product.

When coffee starts to become stale its aromatic, bright, and fruity flavor begins to age. As a result, it loses its exciting and dynamic flavors.

Coffee that is stale is flat and dull. Sometimes it even has a rancid smell. Coffee that is freshly roasted, however, is marked by a creamy foam and indicates that it will be smooth and full flavored.

Roasting Plant Coffee began with the invention of a Javabot, which is a roasting and brewing process that grinds and prepares each cup of coffee in the restaurant when it is ordered. The company operates cafes in the United States and Britain.