Ingredients :

• Fresh spinach — Bulk or bagged, it doesn’t matter — what counts is that they are bright green, not yellowed at the edges. Baby spinach leaves blend better and have a milder taste. If you only have frozen spinach, that works too: the texture will be thicker and very cold, almost like a smoothie bowl.
• Green apple — Granny Smith is perfect here. Its acidity stands up to the lemon and it provides just the right amount of sweetness without weighing it down. A Golden Delicious is too sweet — the smoothie would lose its balance. Keep the skin; it adds fiber and flavor.
• Lemon with the skin — Yes, you blend the whole skin. Scrub the lemon well under hot water first. If yours is waxed or non-organic, peel it — but otherwise, the skin provides an aromatic bitterness that really makes the difference in the final result.
• Coconut water or filtered water — Coconut water gives a slightly sweet base and a rounder texture. Filtered water keeps the flavors cleaner and sharper. It’s a matter of preference. Tap water works too, but in such a delicate smoothie, the taste of chlorine or limescale might be noticeable.