Birch & Meadow Calcium Carbonate Use as a food preservative in fruit juices & preserves Use as an additive in brewing & winemaking Ingredients you can't wait to share with family and friends Packaged in the USA Calcium Carbonate is a natural food preservative used in fruit juices & preserves. Add to the process of winemaking and brewing to reduce the acidity and raise the pH levels of the mixture. Calcium Carbonate can also be used as a natural dietary supplement for elemental Calcium.