BTS’ Jungkook has many nicknames. One of them is “Sold Out King,” due to his ability to sell out anything. If and when the ARMY learns that he’s fond of a certain item, they buy it too so they can find out why he loves it.

Recently, the Korean tea brand TEAZEN revealed that their sales had risen by 500% after Jungkook was seen drinking their products in a live broadcast. That’s good for the company, but not so much for the Golden Maknae himself.

In a subsequent VLIVE, Jungkook said that he couldn’t buy any more of his favorite kombucha because it was sold out. He was bummed yet happy because he knew it meant the company was doing well.

“I could only find two boxes. ARMYs are the best,” he said.

Meanwhile, a Hong Kong supermarket stocked up on TEAZEN products and put a picture of Jungkook in their staff booklet explaining that he’s the K-pop star behind the “sudden extreme demand” for kombucha.

But what exactly is kombucha, anyway?

Kombucha is, very simply, fermented tea. This gives it many scientifically proven health benefits like being a good source of probiotics, containing antioxidants, reducing one’s risk of diabetes, heart disease, and helping with weight loss.

Ah, so it’s delicious and healthy—now we understand why Jungkook loves it so much!

(If you want to try TEAZEN kombucha, you can go here to order a box. It comes in three flavors: Berry, citron, and lemon.)