I've been messing about with gypsum additions to emulate the beer I grew up with - Marston's Pedigree. With some success too, but I'm running into problems that could be putting me off trying further experiments.
At the moment I'm getting about 230ppm sulphate into my water in the form of gypsum, and another 70ppm as Epsom salts. This has a marked effect on the flavour (malt flavours, I don't really notice the reputed effects on hop bitterness). The flavour is instantly recognisable as Pedigree. I'm about at maximum for dissolving gypsum (only about 0.5g/L), it's quite a process, involving putting the gypsum in a litre of water (about 25g), using a stick blender on it for about 1 minute, settling for 2-3 minutes, returning the clear (-ish) portion back to the 60L of brewing water, recharging the flask with another litre, and repeating several times (5-6?) until the gypsum is mainly dissolved.
The problems are:
1: It's time consuming! Taking at least an hour (about 60L for sparging, but another 20 for mashing).
2: I'm getting about 230ppm sulphate dissolved, but Burton water is reputed to have 600-800ppm. About 1/4 can be attributed to Epsom Salt but that's easy to dissolve.
3: While the effect on the flavour is definitely going the right way, those effects are not as strong as the real thing (hardly surprising, I'm not getting so much gypsum dissolved).
4: THE BIG ONE! The flavour enhancement is temporary. From tapping the barrel (at this point only about two weeks from starting brew) there is only three weeks before the flavour effect evaporates. It then becomes an "average" beer. As my smallest brew length is 40L this means there is still an entire keg unbroached.
The beer is served with minimal carbonation (equivalent to 1-2psi), from hand pump and at about 14-5degrees. I am very aware that serving chilled and at high carbonation will kill such subtle effects.
SO... Has anyone got a tried and tested method for dissolving large quantities of gypsum? Some 1-2g/L? I understand that gypsum dissolves best at 40degrees (NOT boiling) and will try that next (I've been trying at 15-20degrees). Has anyone effectively dealt with similar problems with gypsum, especially the "only temporary" one?