SHelf life of drinks

I know this is an off topic, but not sure where to ask this question. However, I got a feeling a lot of people here will be able to answer this relatively easily.

I have made a herbal tea drink. It tastes great. I am loving it. The problem is how can I preserve it, so to extend its shelf life? I am really in the dark in this.

I am planning to offer it for sale in my cousin's local convenient store. Though, that's why shelf life is quite important.

Is there something I should be adding?

Sorry for such a silly question, but would really love to learn.

2 ways that I can think of that foods are made to preserve are pressure canning or freezing. Your drink may not survive either process so try with a small batch.

Is there some kind of preservative that I can add to the drink? To prolong its life?

Pasteurization is what you need.