11amas wrote:The rep was from 5 star, the makers of star san and I thought he specifically said that removal of beer stone was not possible with PBW and that you needed an acid such as star san to do that. Maybe so you don't form new deposits as you clean but I think PBW only works on organics.
I just verified that EDTA will dissolve calcium oxalate at high pH - in a test tube. Now whether it will do it or not when the oxalate is embedded in a protein matrix on the wall of your fermenter may be another matter. The traditional treatment for beerstone uses nitric acid to oxidize the protein and phosphoric acid to dissolve the oxalate. In a percarbonate/EDTA mix you would have the peroxide to do the oxidizing job, the sodium carbonate to raise the pH and EDTA is, apparently, capable of pulling the calcium off the oxalate so, at least theoretically, it might work for beerstone. It's something worth considering because we certainly have the source of cheap percarbonate. Now all we need is cheap EDTA and the cheapest I have found so far is the stuff B&H puts up for photographers who don't want calcium carbonate streaks on their negatives (for younger readers - photographs used to be made on something we called "film" which was exposed to light much as a CCD is and then "developed" to deposit silver particles where the light struck the film) any more than we want it on our brewing equipment.
gruversm wrote:I have a fellow homebrewer friend that uses TSP-phosphate free. Any thoughts about using TSP?
astrobrew wrote:I clean with TSP in the house for years and it worked fine. I hear from members in this forum that is getting harder to find. I have no problems getting it because a friend uses it in his darkroom.
TSP was used as a cleaner for years because it sequesters calcium (as the phosphate) and raises pH to the point where fats are saponified (rendered soluble). The difference between a sequestrant like EDTA and one like TSP is that the Ca-EDTA complex is soluble. Hydroxyl apatite (the product or reation of phosphate with calcium) is not (your teeth and bones are made of it). Thus I would think that TSP would have the potential to leave streaks of apatite if the water is hard. Otherwise, TSP is a fine cleaner used by every housewife in America at one time. It is now considered irresponsible to use the real tsp (as TSP is short for trisodium phosphate, "phosphate free TSP" is a contradiction in terms) as the phosphate leads to eutrophication of waters it winds up in. But then scientists are starting to worry about the buildup of calcium-EDTate in water as EDTA is being widely employed as a built in softener in products like shampoos.
It's intersting that we have 2 chemicals from the darkroom (this was the little room the photographer developed his film in - but that's not important) under discussion in a brewing forum. There is a third (and possibly more). Sodium thiosulfate ("hypo") is great for getting rid of chlorine/chloramine.
