Use less water to make a thicker pot of grits, if you used 4:1 last time and it they were too runny, use a 1/2 cup less water this time.
Bring the water to a full boil over high heat. Once boiling, pour the grits in slowly while whisking the water and grits together vigorously.
Continue to whisk until the water begins to boil again. The goal here is to get all the grit’s starchy surface hot very quickly and evenly and so avoid clumping and burning.
Reduce heat to medium-low or low enough that the pan continues to simmer. Whisk occasionally, or stir with spoon as it thickens, about 20 minutes.
The grits should be soft in the mouth and thick enough to stand up a little on a plate. Turn off heat and let sit for another 5 minutes.