Chalk. Is it good for anything?

When I started fussing with salt profiles to put my mash Ph into range while tweaking my sulfate/ chloride and other flavor ions, Initially I was including copious (double)amounts of chalk, guided by the 50% reported success of chalk in the mash. I did’nt care, it was calcium, precious calcium after all. I even added it directly to the kettle.
I think I knew all along that it is hard to dissolve, having read Kai’s instructions on dissolving it with carbonation, I think I assumed that the mash and the boil acididity would be enough to split the bond and leave me with enzyme/yeast useable calcium and the carbonate would precipitate out.
Fast forward, I’ve quit chalk cold turkey,recently. I’ve done a handful of brews getting my 50+ calcium just using gypsum and calcium chloride, and small (~10-15 ppm sodium) additions of baking soda if i need some bicarbonate.
I also have’nt been doing any “dark” beers that might require a good bit of bicarbonate.
If I do get into some styles that use roast grain, can I assume any dependability of chalk in small amounts? Or would you just go straight to pickling lime?
If I use undissolved chalk in the mash or the kettle, is that calcium useable by enzymes/yeast?

-edit: if you help me figure out how to make beer, I’ll stop bugging you with my salt questions.

I agree chalk is unpredictable . I switched to lime after following Martin’s posts and using his Bru n Water spread sheet.

Chalk will eventually work. But within the time frame of the mash, almost everyone that has used chalk and checked mash pH found that the pH was not where they wanted it. AJ Delange reminds me that chalk will eventually dissolve in the weak acids of the wort, but its not likely to provide the results intended. Another problem is that when chalk is added to the mash, it probably won’t be making that trip into the boil kettle with the rest of the wort where it ‘might’ get the chance to dissolve. Therefore, forget chalk and move on to a more sure method for neutralizing excess acidity (lime or baking soda). Do be careful with the dose of sodium added when using baking soda.

Another option (which I recently found in Gordon Strong’s book “Brewing Better Beer”) is to grind the highly kilned and roasted malts separately, and add them after completion of the mash, just prior to vorlaufing and sparging. That way you still get the color and flavor contributions from those grains, but without the negative impact on mash pH (unless of course you NEED them in the mash to balance out alkalinity in your starting water). I’m planning on using this method for a batch of Dawson’s Dunkel (from the “Decoction Day” episode of BTV), by adding the CaraAroma and Carafa after the finish of the mash of the Munich, Carafoam, and Melanoidin malts. Bru’n Water predicts the mash pH w/o the dark grains to be 5.3- right in the zone. Straight Pilsner malt with my soft water results in a somewhat higher pH, so I’ll be using some acidulated malt in the mash of my next Pilsner. Hope this helps!

Thanks, Brewers.
I had previously unsuccessfully searched far/wide for definative answers to my chalk questions,
Mostly forum discussions that ended with someone/all switching to lime.
I keep thinking I could really use a bit of that calcium it could give me, especially on lighter styles where I want to keep all the additions minimal. But I also seem to like a little bit more sulfate in the styles that I brew the most, so I can happily get my calcium that way.

I’m going to read more about adding the roast/kilned malts at/near the end of the mash. I had heard some brewers advocate doing it this way, and would be the simplest solution should I find myself needing to mash a dark, acidic grist.