800 grams (28 oz) mixed berries (eg strawberries, red and black currants, blueberries, raspberries, blackberries, or cherries)
6 tbsp corn starch
250 milliliters (1 1/6 Cup) cherry juice, divided
50 grams (1.8 oz) sugar
zest of 1 lemon
1.Carefully examine berries, discarding any overripe or rotten fruit. Use only the fleshy part of the fruit: hull the strawberries, remove currants from stem, pit the cherries, etc.
2. Whisk together the corn starch and 5 Tbsp of the juice until smooth.
3. Put all the berries in a large pot and add remaining juice, sugar, and lemon zest. Slowly bring the pot to a boil on the lowest heat setting.
4. Once the mixture starts to bubble, stir in the corn starch/juice combination. Return the jelly to a boil, stirring continuously, then remove the pan from heat once it comes to a full boil.
For reference purposes, my grütze went from this:
The grütze can be served immediately as a warm dessert, or refrigerated overnight and used on its own as a dessert or as a garnish. I think it tastes great mixed with yogurt, mueslix, and pumpkin seeds.