What happens when you switch from iced coffee to hot coffee?

When the weather gets colder, many people swap their iced coffee for a hot cup of joe to warm up from the inside out. If you make this swap, you may notice subtle changes in the way your body responds to hot coffee.

1. You May Notice Milder Energy Effects

There is no difference in caffeine levels between iced coffee and hot coffee. However, people often report that iced coffee gives them a greater energy boost than hot coffee.

If you sip hot coffee more slowly than iced coffee, you may notice a drop in your energy compared to when you drink iced coffee. It takes about 45 minutes for your body to absorb all the caffeine in your cup of coffee, which can last anywhere from 90 minutes to nine hours in your system.

Drinking coffee slowly over an extended period of time can reduce the likelihood of a major energy spike (and subsequent energy crash).

2. You might sweat

Hot drinks (like coffee) can increase body sweating, while cold drinks can decrease it. If you’re used to drinking iced coffee, you may notice that you sweat a little more when you switch to hot coffee.

Contrary to popular belief, it is not because hot drinks increase body temperature. Instead, scientists believe there are temperature sensors lining your digestive tract, and these sensors signal that sweating increases within a minute of drinking a hot beverage.

3. Your stomach might be upset

Research shows that hot coffee is more acidic than cold brew coffee, which could make it more likely to trigger gastrointestinal issues, like stomach upset or heartburn.

Coffee grounds are steeped in cold water for 12 to 24 hours to make cold brew coffee. The lack of heat during brewing means that certain chemical compounds are not released, making it less acidic than hot coffee.

However, not all iced coffees are made using the cold brew method. Most iced coffee is made by cooling traditionally brewed hot coffee. It is unclear whether this type of iced coffee has the same level of acidity as hot coffee.

4. You Can Get a Boost of Antioxidants

There is evidence that hot coffee contains more antioxidants than iced coffee. Antioxidants are compounds that bind to free radicals (unstable molecules that cause cellular damage) and help prevent and delay cellular damage.

However, existing studies are limited and potentially flawed. Further research is therefore needed to confirm whether hot coffee contains more antioxidants.

5. You can drink less coffee

When you switch to hot coffee, you may drink less coffee throughout the day.

You can also drink iced coffee immediately after the service. Many drink it quickly so that the ice does not melt and dilute the coffee. You can even have a second or third cup shortly after finishing the first. On the other hand, hot coffee often requires a cooling period after being served, and it may be too hot for you to drink quickly. It can also be easily reheated. This means that a hot cup of coffee may last longer and cause you to drink less coffee overall.

6. You could consume less sugar

If you switch from iced coffee to hot coffee, you may consume less sugar.

Iced and hot black coffee have very similar nutritional characteristics and contain no sugar. The difference is how they are prepared.

Iced coffee is often served with lots of sugar and flavored syrups, especially specialty iced coffee shops. For example, consider the sugar levels in these popular 16 ounce (oz) iced coffee drinks:

• Starbucks Iced Latte: 11 grams (g)
• Starbucks Iced Caramel Macchiato: 34g
• Starbucks Coffee Frappuccino: 45g

To put this into perspective, the maximum recommended daily sugar intake is 36g for men and 25g for women. Some iced coffee drinks contain more sugar than you should consume daily.

That said, hot coffee can also be sweet, depending on how you prepare it. However, classic barista hot drinks (e.g. flat whites, cappuccinos, and lattes) often come without added sugar, allowing you to add your own.

Pay attention to your sugar intake when ordering coffee or making your own at home. Consuming too much added sugar can lead to weight gain, high blood pressure, cavities, diabetes and other health problems.

7. You might experience a stronger aroma and flavor

Hot coffee tends to have a stronger flavor than iced coffee. Flavor differences result from the Maillard reaction, a chemical process that occurs during heating.

People tend to associate hot coffee with:

• Bitter notes
• Overall intensity
• “Roasted” flavor

Warm, iced, and cold brew coffee are associated with flavors such as:

• Floral
• Fruity
• Sour
• Soft
• Tobacco

You will also notice that hot coffee has a stronger aroma than iced coffee.