EZ Water Calculator Issues

[BKBrews]

I've been using this program for years, made some great beers, but finally got myself a pH meter....

I've done two brews in a row with a calculated mash pH of 4.85 - 4.95. Both times, EZ Water said my pH would be 5.2 - 5.3. I use RO water for both mash and sparge.

I have always been heavy handed with the salts, but that's always to match the desired profile for my beer. For example, my latest beer had 13g Gypsum, 3.75g CaCI, and 7.25g of Epsom. The grain bill was 5.88kg including 100g acidulated malt.

Playing with EZ Water, I'd have to add a HEAP more salts to come close to 4.85. What the hell is going on??

 

[gap]

Have you checked both your scales and your pH meter, they may be inaccurate.

 

[BKBrews]

tested 2 sets of scales both the same, calibrated pH meter to 4.0 pH, and tested it in tap water reading about 6.5 pH (normal range for tap water).

 

[MHB]

As gap said, pH meters really need to be calibrated (two point 7&4 pH is best) and 6.4pH is I would suggest fairly low for most tap water. My local water is usually around 7.5pH.

How salts lower pH is pretty important. Calcium from the mash water and salts you add react with Phosphates in the malt and form insoluble Calcium Phosphate, leaving free Hydrogen ions (acidity is pretty much a count of the number of H+ ions in solution). Point is there is a fairly limited amount of Phosphate in malt, to get lower then that caused by the formation of Calcium Phosphate you need to add acid (I prefer lactic but all acids will lower pH).
The salts will on their own lower the pH a little bit, but you need heaps to get a fairly small effect.

The ideal mash pH is in the 5.2-5.4pH range
Remember that temperature affects the pH, unless your pH meter has really good ATC (automatic temperature compensation) you need to get the sample down to 20oC before testing. ATC is not always all that precise and the further you are from 20oC the less I would trust it. I have some very good pH meters with supposedly the best ATC you can get and I wouldn't trust it too far.

Braukaiser has a good section on pH well worth a read.
This is a good starting point to.
Mark

 

[BKBrews]

As gap said, pH meters really need to be calibrated (two point 7&4 pH is best) and 6.4pH is I would suggest fairly low for most tap water. My local water is usually around 7.5pH.

How salts lower pH is pretty important. Calcium from the mash water and salts you add react with Phosphates in the malt and form insoluble Calcium Phosphate, leaving free Hydrogen ions (acidity is pretty much a count of the number of H+ ions in solution). Point is there is a fairly limited amount of Phosphate in malt, to get lower then that caused by the formation of Calcium Phosphate you need to add acid (I prefer lactic but all acids will lower pH).
The salts will on their own lower the pH a little bit, but you need heaps to get a fairly small effect.

The ideal mash pH is in the 5.2-5.4pH range
Remember that temperature affects the pH, unless your pH meter has really good ATC (automatic temperature compensation) you need to get the sample down to 20oC before testing. ATC is not always all that precise and the further you are from 20oC the less I would trust it. I have some very good pH meters with supposedly the best ATC you can get and I wouldn't trust it too far.

Braukaiser has a good section on pH well worth a read.
This is a good starting point to.
Mark

Thanks for the post, and article.

I normally add lactic acid to my mash as well, according to what EZ Water says should get me to 5.2. I didn't this time because of my 4.95 reading in my last mash.

I did cool my wort, but obviously not to 20c. I suppose I knew I should probably not trust the reading, but went with it anyway. Will make sure I do so in the future. Will test my tap water again today as well, and probably should have tested my RO water.

In your opinion, could I potentially even reach 4.85 pH with 5.88kg grain in a 19.5L mash, without significant lactic addition? It's worth noting that 100g was acidulated malt, 380g was caramel/crystal (carahell and medium crystal), and 60g was carafa spec III.

 

[MHB]

Very few municipal supplies will ever be acidic, there are hundreds of kilometers of cement lined cast iron pipes in the ground, they want to keep the lining in them.
Water chemistry can get a bit over blown. I take a fairly relaxed approach, make sure there is enough Ca in there, add it in any form that works for the beer (Sulphate, Chloride, Lactate or carbonate (very rarely)) then measure the pH and adjust at need.

An all pale malt mash with enough Ca will get down to maybe 6.4pH (in distilled/romo water), dark malts will get you a bit lower, Acidulated will lower the pH by 0.1pH/1% of grist. so your 100g in 5880g is going to lower the pH by 100/5880*100=
well its 1.7% of grist so it will lower your pH by 0.17pH (t's not normally recommended to use more than 5% Acidulated malt).
Short answer is, I doubt that grain bill with the salts as given would be under 5.5pH (that's a wobbly arsed finger count guestimate). I suspect your pH meter isn't really telling you the truth.
Mark

 

[BKBrews]

Appreciate the response. cheers.