Real blood consists of an oxygen-carrying protein called hemoglobin; the more oxygen the blood contains, the redder it becomes. Fake blood is made from sugar and Halloween movie magic — the more science you put into it, the more realistic it will turn out. Fortunately, for dads dedicated to helping their kids terrify the neighbors this Halloween, the American Chemical Society is offering some guidance. Here’s a video by ACS, describing how you can use chemistry to impress your kids, jazz up their Halloween costumes, and turn trick-or-treating into a sweet and spooky learning experience.
Fake blood made its first public appearance at the Grand Guignol Theater in Paris in the early 1900s. This early blood was likely a mixture of red pigment from Cochineal beetles and glycerol, a sweet-tasting liquid that is produced when fats are broken down in water. In the 1940s, the recipe was taken up a notch with the addition of methylcellulose, a chemical that thickened the blood, but not in a way that was thick enough to be noticeable on film. Alfred Hitchcock, dissatisfied with fake blood and working in black and white, was content to rely on chocolate syrup for his bloody scenes.
But then in 1957 The Curse of Frankenstein introduced Kensington Gore (a mixture of golden syrup, warm water, food coloring, and cornstarch), which has since become the industry standard. Others have tried to improve upon it — Herschel Gordon Lewis threw in the anti-diarrheal medicine Kaopectate in Blood Feast (1963) and Dick Smith added a photographic wetting agent in Exorcist (1973) — but sugar-based, essentially edible blood has remained a favorite brew.
The best recipe for dads who want to DIY a Hollywood-worthy bloodbath at home is Sam Raimi’s formula for filmmakers on a budget — six pints of corn syrup, one pint of non-dairy creamer, one pint of red food coloring, and a drop of blue food coloring to deepen the color. But keep in mind that when corn syrup heats up and cools it can crystallize. So make sure to keep Raimi’s recipe away from any Halloween bonfires — unless you want your kid’s face paint to crack.