Understanding Shelf Life of Cold-Pressed Juice
Using Good Produce
Starting with fresh, clean produce is the most important factor in making sure you are serving juice that will last a few days in a refrigerator. If you use rotting produce or produce that has been cut far in advance, it will have already started to oxidize and will greatly reduce shelf life. Make sure you are buying produce from a trusted source, and that you follow health department regulations about cleaning the produce.
You must keep the entire juicing process cold. The FDA recommends at or below 41° F (5° C). If you have a refrigerated kitchen that is ideal, but if not, make sure your produce goes from the refrigerator and is made into juice as quickly as possible, and placed back into the refrigerator. You can also use a blast chiller to bring the product down to correct temperature quickly. If you are delivering the cold-pressed juice, you need to keep it at the correct temperature throughout the entire supply chain. Keeping the product cold will improve color, taste, and extend shelf life.
Juice with a low PH (high acidity) will generally last longer than juice with high PH. For example, lemon juice (which has a low PH) will have a much longer shelf life than carrot juice. You should generally try adding acidic juice to your recipes when possible to improve the shelf life. Have you ever wondered why so many cold-press recipes contain lemon? Now you know! Here is a list of various fruits and veggies and their acidity: http://www.pickyourown.org/ph_of_foods.htm.
True cold-press is a two step process: grind the produce into a pulp, and then press the pulp in a filter bag to extract the juice. A real press will create clean, naturally filtered juice that has a much longer shelf life than juice made on other types of juicers. Lots of juicer technologies claim to be cold-pressed when in fact they are not a press at all. Slow juicers, auger juicers, masticating juicers, and centrifugal juicers do not have a pressing element and create juice that has a lot of solids in it and oxidizes and separates very quickly, often in a matter of a few hours.
In cold-pressed juice, the most common form of preservation is called HPP, High Pressure Processing. This is a process in which the plastic bottles of juice are sent through a high pressure chamber, with the purpose of killing bacteria and extending shelf life. This process can extend the shelf life by about 30 days on some varieties of juice, but not all. Read more about HPP.
Ok, so what is the shelf life of cold-pressed juice?
Following all of the above guidelines, you should probably be able to get 3-5 days of shelf life from your raw juice, but it can be as low as zero days if any of the above guidelines aren’t followed or other factors cause the juice to go bad.