Red Velvet Cake

Variations

• Ermine (roux) frosting: the original southern frosting is not cream cheese. Flour is cooked into milk to a paste, cooled completely and whipped with butter and sugar — far less sweet and much lighter. Cream cheese frosting only became standard late in the twentieth century (thickening sauces).
• Coloured with beetroot: cooked beet puree instead of dye. The result leans purple rather than red and fades a lot in the oven, but it is the one practical way to skip the colouring.
• With no colouring at all: natural cocoa with buttermilk and vinegar gives a russet brown rather than a red. Cakes before the 1930s presumably looked like this, and the taste is unchanged.
• As cupcakes: the same batter makes 12-14, 18 minutes at 175C. The frosting ratio goes up, so they read sweeter.
• Thin-layer versions: many cafes build six or eight thin layers with a scrape of frosting between. The two thick layers here are the American proportion.
• Cakes in the same neighbourhood: sachertorte is chocolate itself, while cheesecake and Basque cheesecake make cream cheese the body rather than the frosting. Brownies use the same cocoa and deliberately do the opposite to the crumb.
• Other American baking: banana bread, chocolate chip cookies, apple pie, doughnuts.
• The name and the legend: the story about a diner being charged for the recipe at the Waldorf-Astoria is repeated everywhere and thinly sourced. What is documented is that the Adams Extract company pushed the cake during the 1930s Depression by selling the colouring and flavouring together, and that is when the red became as vivid as it now is.

Tips

• Which cocoa is the first fork in the road. Natural, non-alkalised cocoa is acidic and still carries its red pigments (anthocyanins), which turn reddish against the acid of buttermilk and vinegar. Dutch-processed cocoa has been alkalised, those pigments are already destroyed, and nothing you add will make it red — it only goes darker. Buy the bag that says "natural".
• Bicarbonate of soda, not baking powder. Soda needs an acid to react with, and that acid is the buttermilk and the vinegar. Swap in baking powder and those acids have nowhere to go: it tastes sour and the crumb changes.
• Vinegar last, into the oven immediately. The soda and vinegar start reacting in the bowl and are largely done in minutes. Batter left standing has lost the gas before it is baked.
• Stop mixing once the flour is in. The name points at texture, not flavour. Develop gluten and the tenderness goes, and at that moment this becomes a red chocolate cake (dough and gluten, choosing flour).
• Only 20g of cocoa. This is not a chocolate cake but a cake with cocoa behind it. More pushes it towards devil's food and buries the red in brown.
• Oil, not butter. The cream cheese frosting means the cake lives and is eaten cold, and butter sets hard at fridge temperature and makes the crumb stiff. Oil does not set, so it stays tender straight from the fridge (serving temperature).
• Gel colouring. Liquid colouring needs tablespoons to reach the same shade, which thins the batter and changes the bake. A teaspoon of gel does it.
• Cream cheese cold, 30 seconds. Runny frosting almost always starts here. Build the structure by whipping butter and sugar first, then fold the cold cheese in briefly. Overbeaten, it does not come back (dairy and heat).
• Use block cream cheese. The soft spreadable tubs carry more water and different stabilisers, and start out too loose.
• Cool completely before frosting — a full hour. In a hurry, wrap and freeze the layers for twenty minutes; spread onto warm cake it melts where it lands (freezing and thawing).
• A perfectly clean skewer means you are past it. A few moist crumbs is the signal. Ovens differ by five minutes either way, so start checking at 22 (what your oven is doing).
• Chill 30 minutes before cutting. The frosting has to set or the cut face tears. A knife dipped in hot water and wiped gives clean layers.
• Keep it refrigerated, take it out 30 minutes ahead. Straight from the fridge the aroma is shut down; a short stand at room temperature brings the cocoa and vanilla back (reviving leftovers).