Heat 2 litres of whole milk in a saucepan over medium heat, stirring occasionally until small bubbles form around the edges, but do not let it boil.
Take the pan off the heat and stir in 60 ml of lemon juice (or white wine vinegar) and a pinch of salt, if using. Give it one or two gentle stirs.
Leave the mixture undisturbed for 10–15 minutes to allow the curds to form and separate from the whey.
Line a large sieve with muslin or a clean tea towel and set it over a bowl. Gently pour the curds and whey into the sieve, allowing the whey to drain into the bowl while the curds stay in the cloth.
Leave the cheese to drain for at least 30 minutes for a soft texture. For a firmer result, drain for 1–2 hours, or gently squeeze the cloth to remove more whey.
Transfer the cheese to an airtight container and store in the fridge for up to 3–4 days. Reserve the whey to use in baking, smoothies or watering plants.