Preheat the oven to 400°F/200°C. Line a rimmed baking sheet pan with parchment paper; set aside.

Combine the milk and lemon juice and allow to sit for 5 minutes until thickened.

Whisk together the flour, caraway seeds, sugar, baking soda and salt to aerate and combine in a mixing bowl. Toss in the raisins. Stir in the egg with a large silicone spatula then start dribbling in the soured milk. You will most likely need somewhere between 1 1/2 cups (360 ml) and the full amount. Only add enough to create a shaggy dough. It will not come together in the bowl but if you pinch a bit of it, it should hold together and you will be able to better assess the moisture level.

Turn the shaggy dough out onto a piece of parchment paper (for easy cleanup) and gather together into a neat ball. Place on prepared pan and press into a 1 1/2 inch (4 cm) thick disc, about 6-inches (15 cm) across. Use a serrated bladed knife to slash the loaf in a deep crisscross on top of the loaf, extending to the edges.

Bake for about 40 to 50 minutes or until the loaf is lightly browned and sounds hollow when you tap the bottom. Cool pan on rack for 5 minutes, then transfer loaf directly to rack to cool further. Irish soda bread can be served warm or at room temperature and is best served the day it is made.