~100-180g Apple Skins
40g Citric Acid
20g Malic Acid
5.0g Salt
850g Water
57g Fructose
25g Sucrose
18g Dextrose
Measure the acid powders into a nonreactive container.
Collect the skin of several apples, preferably from one type of apple and totaling anywhere within the recommended measurement range. This could be done all at once, in which case the apple skin needs to sit in the acid mixture for at least two hours. The skin can also be collected periodically over the course of a week, as long as the pieces of skin are shaken to incorporate with the acid and kept refrigerated.
Take the apple skin-acid mixture and combine it with the recommended measurement of water. Blend this together thoroughly.
Pass this mixture through a relatively fine filter, either an extra fine metal strainer, or a food grade nylon filter bag.
Once you have the filtered liquid, measure and combine the different sugars before stirring into the liquid. You can also scale up the sugar measurements and mix separately for other applications. In which case you would need 100g of the sugar mixture for a batch of acid.
Use as a substitute for strong citrus juice or other culinary acids. Keep refrigerated and it should last at least two weeks.