Search forums. A guy posted he purchased from various places in Peru. Maybe it was made up as he mentioned buying several bottles from different agriculture shops and then went home without it!? It was previously also mentioned in PP handbook about Peru, Custco/Lima. Maybe go for a holiday on a chance of buying it and it would help to speak Spanish of course. Then you just need to stomach drinking it as it tastes disgusting and you'll need to consume it there or take the risk of flying home with it. These days it seems a none starter unless your determined, in funds for a holiday and willing to visit on a slim chance of success.