Introduction:From beginners to coffee enthusiasts, many often have various questions about coffee selection, storage, brewing methods, and health impacts. This article compiles 16 common questions, including whether coffee darkens the skin, how long opened coffee beans last, how to make iced coffee, whether pregnant women can drink it, where acidity comes from, and more. It also explains brewing parameters and flavor essentials in detail, helping you enjoy each cup of coffee with greater confidence.
Coffee has become part of many people’s daily lives, but while enjoying its rich aroma, many also have numerous questions about its finer details. Below are 16 common questions to help you understand the world of coffee more comprehensively, from beginner to advanced levels.
1. Does drinking coffee make your skin darker?
Currently, there is no scientific research proving that components in coffee directly cause the skin to darken. On the contrary, caffeine can promote metabolism, aiding digestion and relieving constipation, which may have potential positive effects on skin health. Additionally, while some believe caffeine helps burn calories, the actual effect is limited. Adding large amounts of sugar or creamer may actually increase calorie intake.
2. How long can opened coffee beans be stored? How should they be stored?
It is recommended to use opened coffee beans within four weeks, and coffee powder even sooner. Unopened vacuum-sealed coffee beans can typically be stored for about four months. For storage, it is advised to use an airtight container, which can be placed in the refrigerator. Adding a small pinch of salt to the container (making sure the salt does not directly touch the coffee) can help preserve aroma. Choosing packaging bags with a one-way degassing valve helps release carbon dioxide produced by the coffee beans while preventing air from entering, thus maintaining freshness. Additionally, try to grind the coffee beans just before brewing to retain optimal flavor.
3. Does drinking coffee lead to calcium loss?
The link between caffeine and osteoporosis is still under research, and there is currently no direct evidence proving that caffeine causes osteoporosis. However, some studies indicate that caffeine may increase calcium excretion. Therefore, those who love coffee are advised to consume more calcium-rich foods, such as milk, or to drink a glass of milk before having coffee, which can help reduce calcium loss.
4. How is iced coffee made? Do you use iced coffee beans?
Iced coffee is usually made by brewing coffee beans with room temperature or hot water, then allowing the coffee to cool to room temperature before adding ice cubes. If you pour hot coffee over ice cubes for quick cooling, the melting ice can dilute the flavor. Iced Mocha is iced coffee with added chocolate syrup, while Iced Cappuccino often contains special spices, offering a richer flavor.
5. Does coffee have to be consumed hot?
While many believe hot coffee tastes best at 85°C, in reality, a high-quality cup of coffee can reveal different layers of flavor from hot to cold. Though aroma may weaken when cooled, the taste can sometimes become clearer. However, since coffee flavor varies greatly with temperature, it’s recommended to enjoy it hot to better appreciate the barista’s craftsmanship.
6. Why does black coffee without sugar still have a hint of sweetness?
Raw coffee beans themselves contain about 5%–8% sugar. After high-temperature roasting, most sugars convert into caramel, contributing to the coffee’s aroma and color, while a small amount of residual sugar provides a subtle sweetness. In addition, tannic acid and caramel reactions released by high-quality coffee beans can produce a unique “bittersweet” flavor.
7. Why does coffee often cause insomnia?
Caffeine mimics adenosine in the human body, preventing it from exerting its calming effect and keeping the nerves stimulated, thus affecting sleep. Each person metabolizes caffeine at different rates, so some may fall asleep peacefully after drinking coffee, while others may easily experience insomnia. It’s recommended to avoid caffeine intake within six hours before bedtime.
8. What kind of water should be used for brewing coffee?
Water quality greatly affects coffee flavor. It is recommended to use filtered or soft water, avoiding hard water with high mineral content (such as high sodium, calcium, or magnesium), as hard water can inhibit the release of caffeine and tannins, affecting extraction. Avoid using tap water with a chlorine smell. You can boil the water and let it cool slightly before use, or use water from the tap first thing in the morning.
9. What makes a good cup of coffee?
There is no absolute standard for good coffee. The key lies in fresh coffee bean quality, proper roasting, and alignment with personal taste. Some prefer strong, bitter richness, while others favor light fruit acidity. As long as the beans are of good quality and brewed well, every cup can be a “good coffee.”
10. What are the three main coffee species?
The main coffee varieties cultivated worldwide are Arabica, Robusta, and Liberica. Among them, Arabica has the most elegant flavor, with caffeine content only half that of Robusta, accounting for about 70%–80% of global production; Robusta is disease-resistant and low-cost, suitable for making instant coffee; Liberica, due to its unique flavor, has a very low market share.
11. How to properly taste coffee?
Tasting coffee is like wine tasting. It’s recommended to first smell the aroma, then take small sips to experience its layers. You may add sugar and creamer according to personal preference. It’s suggested to add sugar first and stir, then add creamer to let the oils float on the surface and enhance aroma. The optimal tasting temperature is when hot, but note that flavor changes as the coffee cools.
12. Is black coffee the only correct way to taste coffee?
There is actually no definitive answer. While black coffee showcases the original flavor of coffee, adding creamer and sugar can also balance certain flaws in the coffee, such as removing astringency or softening bitterness. Traditional Ethiopian coffee ceremonies even incorporate spices, showcasing diverse cultural flavors.
13. Can pregnant women drink coffee?
The U.S. Food and Drug Administration (FDA) once advised pregnant women to reduce caffeine intake, but current research has not confirmed that moderate caffeine harms the fetus. However, because pregnant women metabolize caffeine more slowly and caffeine can cross the placenta, it is recommended that pregnant and breastfeeding women consume it cautiously and preferably consult a doctor.
14. Why do some coffees taste more acidic?
The acidity of coffee is related to variety, roast level, and brewing method. Coffees from regions like Kenya and Colombia naturally have more pronounced acidity. Light roast beans retain more organic acids, resulting in a more acidic taste, while dark roast beans decompose acidic substances at high temperatures, leading to a richer, mellower flavor. Additionally, excessive stirring or prolonged heat retention can also make coffee more acidic.
15. How to choose coffee beans?
When selecting, it’s recommended to choose coffee beans with aroma, no stale smell, and a firm feel. Freshly roasted coffee beans usually have the best flavor about a week after roasting, so it’s best to avoid buying beans sold right after roasting. Single-origin beans should have uniformly sized and colored particles, while blends may have slight variations in color and size, which is normal. If the beans appear oily, check if this is due to over-roasting or prolonged storage. The ideal purchase amount is what you can finish within half a month.
16. How to brew a good cup of coffee at home?
For home brewing, it’s recommended to use an appropriate amount of hot water and coffee powder (for example, 3 grams of coffee powder with 140 milliliters of hot water), with water temperature controlled at 90–96°C. You can try boiling a small amount of warm milk first, then adding coffee powder and hot water, which helps reduce off-flavors and enhance overall flavor. Remember not to let the water come to a full boil to avoid damaging the coffee aroma.
The above content is compiled by CoffeeHunters, a coffee news website.
