I continuously learn new things and this is another of those. Urban outdoor skills has the how to or I guess I should say has accumulated the how to on making verjus. (Meaning green juice as its made from unripe fruit) . Seems back in olden days in France they used verjus as vinegar or lemon juice. They have the tutorial on making your own. While they show how to make it with currants I guess most of the time it is made with green grapes. They also tell you haw to store it in the fridge and give directions for water bath canning if a longer shelf life is desired. Very interesting and definitely something worth knowing.