These are a few possibilities for thickening fruit leathers. While they are all effective thickeners, each one adds its own distinctive quality to a fruit leather. You’ll have to experiment to find your favorite. These ingredients can be found in most health food stores.
WHEAT BRAN: Bran thickens by its bulk, it does’t swell. Add it to breakfast cookies or fruit purees. Use approximately 1/2 cup of bran per 1 cup of thin puree. It is not necessary to soak it before drying. When used with most fruit, it will produce a crisp, wafer-like treat that is great as a snack or crumbled over cereal.
OAT BRAN: This is a recent discovery that has delighted us all. Oat bran produces a wonderfully crisp and flavorful wafer. Use about 1/2 cup of oat bran for each cup of thick juice or thin pulp. Oat bran should be soaked for several hours before drying.
PSYLLIUM SEED HUSKS: Psyllium seed is commonly used as a fiber laxative. It aids intestinal function by providing a non-irritating bulk. Psyllium seed husks make an excellent thickener for juices. It is especially good for grape or berry purees which are generally quite thin. Use one tablespoon psyllium seed husks for every cup of juice. Let stand about five minutes before spreading on Teflon and drying.
GUAR GUM: This is our first love. It adds no flavor or texture. It thickens quickly. Use 1 teaspoon guar gum per 1 cup of juice. Let stand 10 minutes. Too much guar gum will produce a rubbery texture in the fruit leather.
CHIA SEED: Chia seed works best in pulpy mixtures. We especially like to use it with pureed strawberries. Use 2 tablespoons chia seeds per 1 cup pulp, let set for about 10 minutes before spreading on Teflon. Chia seeds were used by Northwest Indians as a survival food. Chia seed leathers make a great energy snack for hikers and backpackers.
FLAX SEED: Flax seed adds a rich, nutty flavor to leathers and wafers. It is great for crackers or grain mixtures. We use it in our tomato-corn crackers. The natural oils found in flax provide essential fatty acids. To protect from rancidity, flax seed should be freshly ground for each use. Use 2 tablespoons ground flax seed for every cup of puree.
SLIPPERY ELM: Slippery elm is a healthful herb with thickening qualities. Slippery elm adds its own distinctive taste to leathers. Use 2 tablespoons Slippery elm per 1 cup of pulp or juice. Soak 5 minutes.
DRIED FRUIT: Your own dried fruits can be used for thickening leathers. Just soak the dried fruit in the juicy mixture and then blend. Amounts will vary but a good rule of thumb is use enough juice to cover dried fruit. Soaking times will also vary.
CRANBERRY/PEAR LEATHER: Powder 1/2 cup of dried cranberries. Stir in 1 cup pear puree. If desired, add a dash of cinnamon. Spread on Teflon and dry.
TROPICAL OAT CRISPS: Mix together 1/2 cup oat bran and 1 cup pineapple/coconut juice. Let stand several hours. Spread on Teflon sheeting and dry until crisp.