A ristretto and a long shot are both espresso, but a ristretto uses less water and a shorter extraction time to create a more concentrated shot than a regular espresso. A long shot uses more water and a longer extraction time to create a less concentrated coffee.
Coffee, like many plants, contains bitter tasting components as a protection mechanism. A little bitterness in your coffee is fine, but it can be unpleasant when it begins to dominates your coffee’s flavor profile.
Red eye coffee is popular among those who need a powerful caffeine fix to keep them wide awake. It’s a simple drink to make, which makes it perfect for the occasion it’s intended for: a foggy-headed morning.