Orange juice concentrate is made by extracting juice from oranges, then removing most of the water through evaporation under vacuum. This reduces the juice to roughly one-quarter of its original volume, making it cheaper to store and ship. The process also strips out much of the natural flavor, which is why manufacturers add carefully engineered flavor compounds back in before the product reaches your glass.
Extraction and Preparation
The process starts at the processing plant, where oranges are washed, sorted, and fed into industrial extractors that squeeze the juice from the fruit. This fresh juice contains pulp, seeds, and cell membrane fragments that need to be removed. Screens and finishers separate out the solids, leaving a cloudy but relatively smooth liquid.
Before the juice can be concentrated efficiently, enzymes called pectinases are often added to break down pectin, a natural gelling substance found in citrus. Pectin can cause the juice to thicken or gel during later processing steps, clogging equipment and creating an uneven product. The enzyme treatment typically happens at around 50°C (122°F) and takes one to two hours, after which the juice flows much more freely through filtration and evaporation systems.
Removing the Water
The core of concentrate production is evaporation. Fresh orange juice is about 88% water, and the goal is to boil off most of it. But boiling juice at normal atmospheric pressure would cook it, destroying flavor and nutrients. So manufacturers use vacuum evaporators that lower the air pressure inside sealed chambers, which drops the boiling point of water well below 100°C.
Most commercial operations use multi-effect evaporators, a series of connected chambers each operating at progressively lower pressures. As the juice moves through these stages, water continuously evaporates and is drawn off as steam, while the juice grows thicker and more concentrated. By the end of the process, the sugar content of the concentrate reaches at least 41.8° Brix, a measurement of dissolved solids. For comparison, fresh orange juice sits around 11 to 12° Brix. So the concentrate is roughly three and a half times as dense with sugars, acids, and other soluble compounds as the original juice.
The USDA sets these Brix minimums as federal standards. When the concentrate is later reconstituted with water for drinking, it needs to hit at least 11.8° Brix to be sold as orange juice from concentrate.
Alternative Concentration Methods
Vacuum evaporation dominates the industry, but two other technologies exist. Freeze concentration works on a simple principle: when you partially freeze a juice mixture, pure water crystallizes into ice first, leaving behind a more concentrated liquid. You then separate the ice from the remaining juice. This method preserves more of the original aroma and flavor because it avoids heat entirely. For decades, freeze concentration was too expensive and lost too much juice trapped in the ice crystals to be practical at scale, though newer equipment has reduced both problems.
Reverse osmosis takes a different approach, using high pressure to force water molecules through specialized membranes while holding back the larger sugar and flavor molecules. It works well for partial concentration but typically can’t reach the high Brix levels that evaporation achieves, so it’s sometimes used as a first step before the juice moves to an evaporator.
What Happens to the Flavor
Here’s the part most people don’t expect. Whether juice is concentrated through heat or other methods, the process strips away volatile aromatic compounds, the molecules responsible for the bright, fresh smell and taste of orange juice. These compounds evaporate easily, which is precisely why they’re lost when water is removed.
To compensate, the industry relies on what are known as flavor packs. Before evaporation begins, some of the volatile orange essence and oils are captured from the juice or the peel. Flavor and fragrance companies (the same firms that design high-end perfumes) then break these essences down into their individual chemical components and reassemble them into specific flavor profiles. One configuration might be designed for the American market, which tends to prefer a sweeter, rounder taste, while another targets European preferences.
These flavor packs are added back to the juice after reconstitution. Because the components originate from oranges, they don’t need to be listed separately on the label. The juice still qualifies as “100% juice.” This is true for both “from concentrate” and most “not from concentrate” orange juice, since even juice sold as not-from-concentrate is typically stored in large tanks for months with the oxygen removed, a process that also strips flavor. Both types get flavor packs before packaging.
Pasteurization and Storage
The concentrate is pasteurized, either before or after the evaporation step, to kill bacteria and extend shelf life. It’s then rapidly cooled and either frozen for storage in large tanks or packaged directly into cans and containers. Frozen concentrated orange juice can be stored for a year or more at proper temperatures without significant quality loss.
The frozen concentrate format dates back to 1945, when the Florida Department of Citrus developed the process. The patent was given to the U.S. government in 1948, which helped launch the frozen food industry as a whole.
Reconstitution: Turning It Back Into Juice
When concentrate is turned back into drinkable juice, filtered water is blended in to bring the Brix level back to the 11.8° minimum. Flavor packs are added, and pulp (which was separated and stored earlier) can be reintroduced depending on the product style. The reconstituted juice is then pasteurized again and packaged for retail.
If you’re buying frozen concentrate in a can to mix at home, you’re doing this reconstitution step yourself by adding three cans of water per can of concentrate, which approximates the correct ratio.
How Nutrients Hold Up
Concentration and freezing actually preserve vitamin C better than you might think. Orange juice reconstituted from frozen concentrate contains about 86 mg of vitamin C per cup at initial preparation. That compares favorably to many ready-to-drink juices on the shelf, which average 27 to 65 mg per cup when first opened. The difference comes down to oxygen exposure: liquid juice in a carton slowly loses vitamin C through oxidation during storage and transport, while frozen concentrate stays sealed and stable.
Once you reconstitute frozen concentrate and store it in the fridge, vitamin C drops at roughly 2% per day, the same rate as any opened juice. After four weeks of refrigerated storage, reconstituted concentrate retains 39 to 46 mg per cup, while ready-to-drink juices can fall to nearly zero. So if vitamin C content matters to you, frozen concentrate mixed fresh at home often delivers more than the premium carton that’s been sitting in the cold case.
Labeling Rules
Federal standards of identity govern what can appear on an orange juice label. If the product is made entirely from reconstituted concentrate, it must be labeled “from concentrate” or “reconstituted.” If fresh-squeezed (pasteurized) orange juice has some concentrate added to boost the solids content, the label must include a phrase like “prepared in part from concentrated orange juice” or “with added concentrated orange juice.” These rules exist because consumer preference has shifted strongly toward juice perceived as fresh, and regulators want the distinction to be clear on the package.