Though I don’t recall ever having a beer taste pretty good throughout fermentation then turn salty towards the end like you describe, I have had some bad experiences using BeerSmith’s water module.
BeerSmith is my go-to for recipe formulation, gravity predictions, brewday calculations and such, but I’ll leave the water chemistry to the guy with a degree in water chemistry. So, I use Bru’n Water for water calculations and add the prescribed salts from it into my BeerSmith recipe.
Anecdotally, I recall when I began using Bru’n Water that the additions seem much smaller than the BeerSmith recommendations. So much so I remember skeptically commenting that the small additions wouldn’t make any difference at all. Martin assured me I was wrong. Glad I listened.
Before cashing in your chips, let it finish, package it (hopefully you keg), and let it mature. In the end you might have a dumper or just a green beer that matures into a good pint. Bad news doesn’t get better with time but sometimes bad beer matures into ‘ain’t bad’ or even ‘pretty good’ given a little time.
If you do end up with a dumper you could dabble in some post fermentation corrections. Mix up a X ppm solution of calcium chloride and add it in measured amounts per measured amount of beer to see if you can balance it out. If it works scale up the solution to your kegged volume (this is why I hope you keg). You might salvage a batch from zero to drinkable ...but you might make Alka Setzer, too. I figure since you’d be at zero anyway what’s the harm in trying.
As a side note: one reason I got the Tilt floating hydrometer is so I would not have to take multiple samples of wort throughout fermentation. I was always concerned about opening and closing the BrewBucket sample valve multiple times. It is quite a resource commitment, and once I navigated the learning curve, I can recommend the Tilt for no better reason than to know when the fermentation is at a point that an action needs to be taken (spund, D rest, rack, etc.). In other words, I recommend taking very few samples.
Hope this helps. Look forward to hearing about the outcome.
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