Unopened bottled Lemon Juice will last for up to 12 months at room temperature.
When opened the bottled Lemon Juice will last for 6 to 12 months in the fridge.
Fresh lemon juice lasts for up to 4 days in the fridge.
If you want to keep fresh lemon juice longer than 4 days then you can put the fresh lemon juice into a freezer safe bottle and freeze it.
If the lemon juice is in a plastic bottle such as a soda bottle then it will be safe in the freezer.
Freezing the lemon juice makes it last longer.
Just like freezing lemonade makes the lemonade last longer.
Freezing temperatures prevents spoilage and extends the life of the lemon juice and lemonade.