BeerBorg

Decided to do a BIAB batch today adding the 5.2 stabilizer instead of doing traditional all-grain where I usually add minerals based upon the spreadsheet Bru'n. This was very time consuming, so I put the 5.2 stabilizer along with BIAB brewing to the test.
After adding the 5.2 stabilizer, my mash ph was at 5.6. Way too high in my opinion for a product that advertises 5.2. Seems like a gimmick to me. In the end, I added 5.5 oz of acid malt which was bought in advance, because I didn't trust this stuff to actually lock in at 5.2. In the end, my mash Ph was 5.4.

Yes, this 5.2 stabilizer is going in the garbage

I've never tried it. But I have read other reports that it doesn't work well. Thanks for sharing your experience, you may have saved someone the trouble.

I was a big user of it too though my water is pretty good to begin with (so sayeth the water board) but the last 3 brews I've used nothing but brewing salts and am looking into a PH meter. Sadly, the good ones are very expensive and as I am pretty happy with most of my beers, I'm not going to be buying one but, I am in some agreement with you. Not everyone needs it. In fact, many beers aren't good at 5.2 and should be at a higher Ph.

It works for me been using for several years now. My water is straight out of a 200' deep well. My beers are more balanced. However for pils I do use salts since I use RO water from the house filtering system

I had come across this write up on the Bru'n Water site when researching water profiles last year, I figured it would be a good fit here too.

SPECIAL NOTE: Five Star 5.2 Stabilizer is indicated by its manufacturer to "lock in your mash and kettle water at a pH of 5.2 regardless of the starting pH of your water". Evidence by homebrewers indicates that this product does not produce a mash pH in the preferred room-temperature range of 5.3 to 5.5. That evidence shows this product does produce some pH moderation in waters with high Residual Alkalinity. However, the mash pH tends to center around 5.8 (room-temperature measurement). While 5.8 pH is acceptable, it is at the upper end of the desirable mashing range.

The evidence also shows that in waters with low Residual Alkalinity, this product shows little effect on mash pH. Since Five Star 5.2 Stabilizer is a compound with high sodium content, its use will elevate the sodium concentration in the brewing water. High sodium content can be undesirable from a taste standpoint in beer. Proper alkalinity control of mashing and sparging water may produce more acceptable brewing results for most brewers than with the use of 5.2 Stabilizer. To add emphasis to difficulty in using this product, the following conversation posted on Homebrew Talk between noted brewing water expert, AJ DeLange and the chemist from Five Star Chemical regarding their 5.2 Stabilizer product.

"Tipped a few last night with the chemist who designed this product and was able to confirm that it is indeed a mix of phosphates (mono and di basic) that accounts for the presence of the malt phosphate. This is something I have long suspected and am pleased to have finally confirmed. Good manners prevented me from pressing him on it's efficacy and suitability relative to the statement on the label. But his comments on it were basically that most brewers shouldn't use it/need it and that it was put together for a particular brewery that had variable source water and no desire to make any effort to track that variability."

And the plot continues. I like what I'm getting using water treatment though I admit, I'm in over my head. Guess I've either just been lucky or good. Either one works for me.

Never used this stuff, but heard both good and bad about it. All depends on what you are trying to do with your water and what you are working with, results with any water treatment will be different for everyone.

FWIW, I have only used mixed half and half Spring water and good old Lake Erie tap water for mash/sparge and if I had to top off used from an unopened gallon of spring water or distilled. I have made a couple of pretty good beers with this water.

I tried it for a couple of brews and ended up giving it away. Didn't seem to improve my beers.
Switched over to using a mix of filtered tap and spring water depending of the style adding 2-2.5% acid malt.
Been exceptionally happy since then. Since I do mainly lagers under German Purity Law I do not treat.