Looking to brew a nice creamy milk stout. I want it be be big (1.075) and malty with the sweetness to come through but I also don’t want it to be tiresome on the palate. I start with RO and was thinking of:
The chalk won’t dissolve and contribute the alkalinity that you’re counting on. I don’t recommend using chalk. Count on baking soda to provide the alkalinity. The amount of sodium that it adds, isn’t enough to worry about since you only add baking soda to the mashing water. The sparging water dilutes the sodium content in the finished wort.
While you don’t really want a lot of sulfate in your water for that beer, you do want some. I suggest you consult the Black Full and Black Balanced profiles to give you an idea of how much sulfate you might consider.