7 Days Without Washing: Putting a Wool T-Shirt to the Test
When researching Merino wool, you may often come across phrases like “Merino wool has deodorizing properties, so it is less likely to smell!” or “Because it does not develop odors easily, you do not need to wash it frequently!”
To be honest, it is natural to wonder, “Is that really true?” I usually wear UNIQLO AIRism as an inner layer, but once I sweat, it still starts to smell like sweat, so I always wash it after wearing it for a day. Wearing it again the next day without washing is simply unthinkable.
So this time, I wanted to find out the truth behind Merino wool’s deodorizing function. I became the test subject myself and wore a Merino wool T-shirt almost 24 hours a day for about one week!
The Result After Wearing a Merino Wool T-Shirt for One Week
For this test, I wore C-one’s “C FLEX Wool T-Shirt” almost 24 hours a day for one week.
Details of the Wear Test
First, here are the details of the wear test.
■About the Wearer
- 28-year-old male
- Height: 163cm, weight: 67.1kg. The standard weight for this height is 58.5kg.
- Walks 10,000 steps a day, 3 to 4 days a week
- Goes to the gym about twice a week for weight training. Training experience: about one and a half years
- Does not drink alcohol or smoke
- Does not often eat oily or spicy foods
- Drinks protein powder about 2 to 3 times a day
- Tends to sweat on the back and underarms. The back sweat is especially heavy, to the point where the back can become soaked
■Wear Conditions
- Wore the Merino wool T-shirt directly against the skin as an inner layer
- Exercised while wearing the Merino wool T-shirt
- Continued wearing it except when taking a bath
- After returning home from work, my wife checked the odor
- The test would end immediately once any sweat odor was detected
■Detailed Test Conditions
- Test period: From Monday, June 3 at 12:00 a.m. to Monday, June 10 at 9:00 p.m. One week plus one day
- Exercise: 10,000 steps per day except on Sunday, June 9. Gym workout on Thursday, June 6 for one and a half hours
※The gym was visited only once during the week. Instead, 10,000 steps were completed on six days.
▼Step count measured with Galaxy S Health
■Weather and Temperature During the Wear Test Period, Osaka
| 6/3 | 6/4 | 6/5 | 6/6 | 6/7 | 6/8 | 6/9 | 6/10 | |
|---|---|---|---|---|---|---|---|---|
| Weather | Sunny | Sunny | Sunny | Cloudy | Sunny | Cloudy | Cloudy, then rain | Cloudy, then sunny |
| High | 26.1℃ | 25.6℃ | 28.6℃ | 26.2℃ | 29.4℃ | 30.1℃ | 22.5℃ | 28.9℃ |
| Low | 16.2℃ | 16.3℃ | 16.9℃ | 17.6℃ | 19.3℃ | 19.0℃ | 18.7℃ | 17.8℃ |
| 10,000 steps | 〇 | 〇 | 〇 | 〇 | 〇 | 〇 | ✕ | 〇 |
| Gym | ✕ | ✕ | ✕ | 〇 | ✕ | ✕ | ✕ | ✕ |
Wear Test Result
As a result, around 9:00 p.m. on Monday, June 10, I noticed a sweat odor coming from the underarm area, so I ended the wear test at that point. My wife said, “It smells a little,” and after checking, the odor was coming from the underarms. It is possible that the odor had already started while I was at work, so I concluded that even for someone who sweats easily, wearing it continuously for about one week did not lead to a noticeable odor until near the end of the test.
However, the result may differ under the following conditions.
- If the test is conducted in a different season with the same level of exercise
- If the wearer’s gender, age, weight, or other physical conditions are different
- If the wearer drinks alcohol or smokes
- If the wearer often eats oily or spicy foods
- If the wearer does not exercise
- If the amount of exercise is greater
- If the wearer sweats more than the tester
View the C FLEX Wool T-Shirt
For Everyday Use, It May Be Possible to Wear It Even Longer
This wear test involved quite a lot of exercise, and the conditions were rather demanding. If used as loungewear, I felt that it might be possible to wear it for around two months without any noticeable odor. Also, if worn when going out, as long as the activity level is not as intense as in this test, I think it could probably be worn for about two weeks to one month without washing.
In general, people do not wear the same piece of clothing 24 hours a day, and what we wear often changes depending on our mood. Some people may also wear another inner layer underneath the Merino wool T-shirt used in this test, so the results may vary greatly.
Next time, I would like to conduct a test under conditions closer to everyday life and see when the odor starts to appear.
Product Used in This Wear Test
| Price | 16,500 yen, tax included |
|---|---|
| Size | S・M・L・LL |
| Material | 100% wool |
| Country of origin | Made in Japan |
Even after being worn continuously for one week by someone who sweats easily, this T-shirt showed impressive odor resistance. We hope you will experience its deodorizing power for yourself.
First-time customers can also try it with confidence thanks to our size exchange within 7 days and free shipping.
What Happens If You Do Not Wash a Merino Wool T-Shirt?
As shown in the result of this experiment, odor will eventually appear, so it is best to wash it when needed. However, unlike a regular T-shirt, a Merino wool T-shirt does not need to be washed frequently. You may wonder, “Then how often should I wash it?” Basically, we recommend washing it when it gets visibly dirty or when you notice odor coming from the Merino wool T-shirt.
If wearing the same item for a long time without washing feels uncomfortable to you psychologically, feel free to wash it whenever you prefer. For washing instructions, please refer to “Quality Care for Wool Products, So You Can Wear Them Longer.” We hope you find it helpful.
Summary
What did you think of this wear test? Before starting the test, I thought it would probably end in about three days, so I was honestly surprised that it lasted for one full week.
There were times when I wanted to wear a different T-shirt, but I held back. Wearing the same piece of clothing 24 hours a day was mentally uncomfortable and honestly quite challenging. However, I was able to personally experience Merino wool’s deodorizing function, so it turned out to be a valuable experience.
If you often sweat or are concerned about sweat odor, we hope you will try a Merino wool T-shirt and experience its deodorizing function for yourself.
If you are interested but cannot decide right away, we also recommend registering as a member.
We are currently offering a 10% OFF coupon for new registrations. You will also receive a special coupon during your birthday month.