Yuzu + honey and water only
The yuzu [YOO-zoo] is a Japanese citrus fruit which about the size of a tangerine and is quite sour. Most commonly the rind is used to flavor various dishes such as vegetables, fish or noodles. The Yuzu is difficult to find in the US and Europe. There is a farmer grow yuzu in US. You can obtain bottled juice or dry, powdered yuzu.