Originally Posted by briggssteel
Right. I did know some alkalinity was necessary after my last stout I did. The water had 40 ppm of total alkalinity. I came in at 5.1, added a half teaspoon of chalk and nothing. This is why this time I'm using baking soda instead of chalk and why I'm adjusting my water to 62 ppm total alkalinity. Do you think I'd need to be any higher? It says I'll be adding 30 ppm of sodium which from what I've heard so far is totally acceptable.
As for the epsom salts, I thought magnesium was important for yeast health? Do you mean epsom salts would better suit a bitter aggressive beer because of the sulfates that come along with it? If so I've taken those into account by balancing my sulfates with chlorides.
The Mg supplies its own bitterness or tartness perception, beyond what the sulfate provides. If the beer has a bitter focus, then adding the Mg can be a good idea. As mentioned by others, malt provides enough Mg to the wort for yeast health, so additional should not be necessary unless desired for taste.
The pH response with the use of chalk is typical of many user reports I've been given. It just doesn't work effectively. To anyone brewing with RO water or low alkalinity tap water, get a pound of pickling lime and learn to use that. A pound should last a typical homebrewer a really long time since you don't use much. If you have homebrewing buddies, split the pound with them. Be sure to keep the lime in a tightly sealed container since it will eventually revert to chalk if moist air gets to it.
If that 5.1 reading was at room temperature, it was a little too low and confirms the need for alkalinity.
The 30 ppm Na should be OK. I like a touch in my beers. But it would be OK to not have it in there at all.