Wash elderberries, place into a pot, add 1 liter of water, 100 grams of sugar, lemon zest, cloves and cinnamon. Cook under a cover on low heat for about 30 minutes. Core apples and slice into pieces. Stew apples with 250 milliliters of water, 50 grams of sugar and lemon juice. Strain the elderberry broth, throw away berries, cinnamon and cloves. Dissolve the starch in the cold water, pour over the broth, bring to a boil, add slices of apple and serve.