Most grocery stores suggest that unopened containers of lemon juice can be left at room temperature, yet it is best to store them in a cool, dry spot away from direct sunlight to preserve the taste and freshness and extend its shelf life. Once a lemon is cut, the juice inside the lemon starts to oxidize, which can affect its taste and quality.
On the other hand, freshly squeezed lemon juice can last longer than some other juices because it has a lower pH, which makes it more acidic. The acidity of lemon juice helps to inhibit the growth of bacteria, which can cause spoilage. However, the shelf life of freshly squeezed lemon juice can still be relatively short, and it may start to spoil after a few days if it is not stored properly.
Therefore, when a lemon juice container is opened, it is recommended to put it in the refrigerator due to the fact that air and warmth can cause bacteria, yeasts, and molds to grow, compromising the quality of the drink and potentially causing food poisoning. It's worth noting that some manufacturers may recommend refrigerating even unopened lemon juice to extend its shelf life and maintain its quality.
Freshly made juices (including cold-pressed juices) need to be refrigerated in airtight containers or glass bottles (or jars) because they don’t go through the pasteurization process. Pasteurization requires heating the juice to high temperatures to kill bacteria, which can also weaken the beneficial nutrients and enzymes
In contrast, juicing with a press that doesn't involve heat is a way to preserve more nutrients and enzymes than other methods, and must be kept refrigerated at temperatures below 39 °F.
How Long Does Lemon Juice Last?
Fresh squeezed lemon juice that's been consistently refrigerated will last 3 to 4 days after opening. You can preserve lemon juice by freezing it if you need to keep it longer than 3 to 4 days.
However, make sure to let it thaw out completely before consuming it to prevent a diluted flavor, as the water melts at a faster rate than the vitamins.