Juices are created by mixing two of any food items in the blender upstairs at Columbian Roastmaster. All juices restore full health, but their effect only last a short amount of time. There are multiple ways to make juices:

Energizer (unknown effect) = Randomizer + Zombait
Nectar (unknown effect) = Orange Juice + Snacks
Quickness (move 5x faster) = Wine + Yogurt
Randomizer (random effect or stomachache) = Cooking Oil + Snacks
Spitfire (spit becomes deadly) = Baguette + Snacks
Untouchable (invincible to any attack) = Baguette + Pie
Zombait (zombies more attracted to you) = Pie + Snacks