Boil water. Pour the liquid into a 2 quart (1.9 l) saucepan with high sides and add the baking soda. I know this is a huge pan, but it can foam up with the baking soda so the high sides will keep it from foaming over and spattering. Be careful that you don't use more baking soda than the recipe calls for. Bring to a boil and keep an eye on it.
Add grits. The moment it boils, pour in the grits slowly so each grain gets "shocked" to prevent clumping. Watch! As soon as it comes to a boil again, turn the temp down to the lowest possible temp and stir down the foam. When it is no longer foaming, put on the lid. Let it sit for 20 minutes, stirring or whisking every 5 minutes or so to keep it from clumping or sticking to the bottom. A wooden or silicone spoon is best for this task so you can get down into the corners of the pan and prevent burning. It should get thick, but not gummy.
Add the enrichments. Add the butter and stir it in until it melts and is evenly distributed. If you are adding herbs, now's the time. If you are adding cheese, now's the time. Mix it in about 1/3 at a time. If it is too thick, and it probably will be, add an ounce (29.6 ml) of liquid and stir. Add more liquid if necessary. If it is too wet, leave the lid off for a few minutes. When it has thickened but is still a little runny, season it to taste with salt and pepper. Take it off on the runny side. It will thicken by the time you serve it.
Serve. Remove from heat and ladel into bowls. If you are using other toppings like grilled shrimp, grilled ham, grilled andouille, or bacon, now's the time. Serve with butter, salt, pepper, and cream on the side in case your guests want to doctor it.