A bandleader's blender
The electric BLENDER was patented in 1922 by Stephen Poplawski, who wanted a better way to make malted milk drinks. It was made famous in the late 1930s by Fred Waring, a popular American bandleader, who backed an improved machine, sold it as the Waring Blendor and demonstrated it on tour. The blades of a powerful modern blender can spin at more than twenty thousand turns a minute. Doctors used it in hospitals, and the scientist Jonas Salk later used Waring blenders in his work on the polio vaccine.
Blended fruit drinks were sold in American health-food shops in the 1930s, but the SMOOTHIE became a craze from the 1960s and 1970s, when juice bars in California began blending fruit with ice, yoghurt and juice.
Why smoothies are thick
A BANANA is the secret in many recipes. Its soft flesh is full of a sticky substance called pectin, which thickens the drink and makes it creamy without any milk, and a banana with brown spots is sweeter, because more of its starch has turned into sugar. FROZEN fruit does the job of ice without watering the drink down. OATS, ALMOND butter and YOGURT add thickness too, and PROTEIN powder turns a smoothie into a meal for some athletes.
Leafy greens such as SPINACH and KALE disappear into a green smoothie, and the sweetness of MANGO, PINEAPPLE or HONEY hides their taste. Blending keeps the fibre from the fruit, which juicing throws away, though drinking fruit is still an easy way to have a lot of sugar in one go.
Milk that never saw a cow
Plant milks are older than they look. Medieval European cooks made ALMOND milk by soaking and grinding almonds in water, partly because the Church banned animal products such as milk on its many fasting days. Oat milk is much newer: it was developed by food scientists at Lund University in Sweden in the 1990s, looking for a drink for people who could not digest milk.
COCONUT water, the clear liquid inside a young green coconut, is different from coconut milk, which is squeezed from the grated white flesh. Coconut water is sterile until the nut is opened, and there are reports of doctors in the Pacific using it as an emergency drip during the Second World War. HONEY hardly ever goes off, because it holds so little water that germs cannot grow in it; archaeologists have found honey in ancient Egyptian tombs that had not spoiled.
Avocado with chocolate
Many countries drink smoothies under other names. In Brazil, a vitamina blends fruit with milk, and an AVOCADO vitamina is a sweet treat. In Indonesia, avocado juice is often served with a swirl of chocolate syrup. India's lassi blends YOGURT with mango or spices.
The ACAI berry, the purple fruit of a tall palm tree in the Amazon rainforest, was an everyday food there long before it became fashionable. In northern Brazil it is eaten with fish or savoury dishes, while surfers and fighters in Rio de Janeiro made it popular as a sweet frozen bowl in the 1980s. Our rainforests page covers where it grows. COCONUT water, GINGER, PEACH and every kind of BERRY, from BLUEBERRY and STRAWBERRY to RASPBERRY, finish the menu.