In a large pot over medium-high heat, whisk together all ingredients until smooth. Bring to a simmer and heat until the mixture just begins to curdle (do not stirr while it is reducing). For a drier ricotta with bigger curds, continue to simmer 1 to 2 minutes longer until mixture completely separates. Pour mixture into yogurt strainer or coffee filter.
Stop draining when mixture begins to look like ricotta, 5 to 15 minutes, depending on how dry you like it. Transfer to an airtight container and store for up to two weeks.