To clarify batter consistency: Think of consistency as building block of whatever you’re making. Thin batters pours easily; they’re meant for cakes such as chiffon or angel food. Those types of cake depend upon whipped egg whites for their lift (not just chemical leaveners). The thinness lets them climb quickly up into tall tube pans without ripping the tender structure of the cake. Use a thick batter for one of these cakes and it won’t climb up the sides of pan and give it any structural lift. Knowing where to start is important; each type have a particular job to do.
Home-baked drops fall slowly off the spoon in medium batters that are often used for vanilla or yellow butter cake; they drop in slow, thick ribbons that hold their shape for just a second before settling back into bowl. The batter falls in slow ribbons and it doesn’t spread out quickly on pan, either. For butter cakes, the flour give structure, and the fat (usually butter) is creamed with the sugar, so air bubbles gets trapped in the batter. Mix until the batter is smooth, but not shiny or elastic, because overmixing develops too much gluten and makes the cake more like chewy bread than a tender crumb.
How to Check Your Batter
Not Pourable: Thick batters are thick because they’re meant to be scoopable (and not pourable). Think carrot cake. Banana bread. Fruitcake. Thick batters can includes lots of moisture-rich ingredients, such as shredded carrots or mashed bananas, which soak up moisture and help the batter thicken itself. To get them in your pan, you’ll have to reach for a scoop (or spoon). Don’t try to add milk to thin a batter like this; it’ll turn your moist cake into a soggy nightmare. The thickness isn’t a mistake, it’s intended.
Consistency, especially when baking at altitude, is also affected by environmental conditions. Because of lower air pressure, batters will be lighter and therefore rise quicker than evaporating sooner as well, resulting in collapsed centers. Simply reduce your leavening agent or add a little extra liquid and you’ll correct that imbalance and have a successful bake.
Most troubleshooting is just an observational thing: Too runny? Add some flour, tablespoon by tablespoon. Until it has the right drape. Too stiff? Loosen with a splash of buttermilk (or milk)…but not so much that it lose its structure. Letting ingredients come to room temperature before combining also helps; adding cold eggs to creamed butter will make them curdle. It’s alarming-looking and sometimes bakes out okay anyway, so long as you’re gentle.
Confidence is built when you can see, feel, and taste the differance. You need to trust yourself when baking. Know where that ribbon stage is, look at how it falls into pan, and adjust based off your own kitchen. Knowing exactly what your cake will look like out of the oven takes away the guesswork so you don’t should of wonder if it was done or not.