Primary Kosher Concerns:
Apple and orange juice: Although apple and orange juice don’t inherently cause any kosher ingredient issues, the equipment on which they are produced can be problematic. With all other juices, even if the ingredients are straightforward, they could have been produced on equipment running non-kosher grape juice and non-kosher sports drinks.
Sports drinks: A sports drink might contain non-kosher glycerin, as well as many other non-kosher ingredients. Additionally, carmine extracted from beetles (not kosher!) is often used as a colorant in beverages as a replacement for red # 40. “Natural” does not mean kosher.
OUD on Orange Juice? The reason why orange juice containers often look like milk containers is that dairies want to maximize the usage of their equipment. The problem is, even if they rinse off the equipment between milk and orange juice productions, it might not be at sufficient kosherizing temperatures. Hence, the hot pasteurization of the orange juice would be conducted on dairy equipment, rendering the juice OUD.
OU Kosher beverage facilities: At an OU Kosher-approved facility, not only are all of the ingredients kosher, but the beverages are either bottled on dedicated lines, or produced on lines that are routinely koshered at OU Kosher-approved temperatures. With the proliferation of allergens today, and the awareness thereof, companies now view non-kosher as another “allergen” which requires a boil-out to remove.
Please be aware: Shelf-stable juices are generally hot-filled (pasteurized) to remove bacteria. However, even cold-filled beverages might be “flash pasteurized” in the process to remove bacteria. Hence, the previous kosher issues apply.
Rabbi Moshe Heimowitz serves as OU Kosher RFR for the Western NY region. His route includes both beverage and dairy plants.