Green juice typically stays fresh for about 2-3 days in the fridge. To make it last longer, store it in airtight containers and add a squeeze of lemon juice for extra preservation. I've found that prepping small batches and consuming them within a couple of days works best to maintain freshness and nutrient content. Have you tried freezing any portions for later use? It's another trick I learned that can extend the shelf life without compromising taste or nutrients.