We do not recommend frozen spinach, as it loses taste and, above all, nutrients due to the freezing process - e. G., enzymes that are sensitive to cold. In addition, packaged frozen spinach from the refrigerated section of the supermarket is usually blanched before freezing, which denatures all heat-sensitive enzymes and nutrients. All the positive effects that the green smoothie is supposed to have are then lost. If you can't get your hands on fresh spinach, simply use other leafy greens: radish leaves, lamb's lettuce or Postelein. When it comes to leafy greens, variety is key anyway.