Blood effect that is Washable and Eatable for Halloween and Day of the Dead

I work at the San Francisco Opera and we use a blood on stage filmed in high definition that looks great and is eatable and washable too.
 This recipe is all made from all store bought items.

My good friend Jim Holden is the "Blood PathoJim" we call him, and is shown mixing a batch up in our Prop Shop.
Browse the shows photo gallery and find the blood!
http://sfopera.com/o/288.asp

Step 1 Ingredient List

Corn Syrup---- (2L) 8.5 cups
Chocolate Syrup---- (500mL) 2 cups, 2 tbsp
Water---- (500mL) 2 cups +/-
Corn Starch---- 2 tbsp (heaping)
Coffee Mate---- (yes!) 3 tbsp (heaping) This makes it Washable....
Red Food Coloring---- (15mL)  3 tsb
Yellow Food Coloring---- (3mL) little more than 1/2 tsp.