To make Yorkshire puddings, plain flour is typically used. The amount of flour needed varies slightly depending on the recipe, but most recipes call for around 140g of plain flour. Some recipes, like the one from Serious Eats, use a flour-to-liquid ratio of 75g of flour for every 200g of liquid. Its worth noting that some people recommend using "strong flour" or breadmaking flour for Yorkshire puddings, as it has a higher gluten content and can help the puddings rise more. However, plain flour is still the most commonly used flour for this dish.