Very High Post Boil pH

[Indian_villager]

Post boil pH is HIGH AGAIN. 5.76 this time. Gravity sample smelled and tasted fine as opposed to the previous batch. Both pH and gravity reading were taken at at 68°F.

Calibration solutions are reading correctly, so I'm not quite sure. I started rinsing my alkaline cleaner with hot water but maybe it's still not getting off.

You say calibration solutions are reading right. As in after you took your 5.76 sample you checked the calibration solution again?

 

[Bobo1898]

You say calibration solutions are reading right. As in after you took your 5.76 sample you checked the calibration solution again?

I did not recheck after taking either the mash or post boil samples. But after recalibration, I rinsed and put them back in 7.01 and 4.01 to verify they read correctly. My mash sample was taken within 10 to 15 minutes after this. Post boil reading was obviously way down the line---three hours maybe.

Hypothetically, I can check the probe in the buffer solutions today.

 

[Bobo1898]

Tonight I had the chance to check the probe in buffer solutions again to make sure the probe isn't faulty. The solutions read as follows:

7.01 buffer reading as 7.00/01
4.01 buffer reading as 3.99/4.00

This has been 3 days since brew day, when I recalibrated. The mystery lives on.

 

[Bassman2003]

That is a mystery.

 

[Indian_villager]

You def have a contamination of some kind. Have you tried following your cleaning steps as you do them normally, waiting for everything to dry. Then filling up all fluid contacted vessels, exchangers, and valves with some water. Measure the pH of the water before it goes in your vessels, and measure the pH of the water after it contacts everything. This is the only sure fire way to know. You can also measure the pH at individual steps as you go, measure after adding to the kettle, after circulating through the pump, after contact with whatever type of chiller you have. This way you can narrow down where to focus.

 

[Bobo1898]

You def have a contamination of some kind. Have you tried following your cleaning steps as you do them normally, waiting for everything to dry. Then filling up all fluid contacted vessels, exchangers, and valves with some water. Measure the pH of the water before it goes in your vessels, and measure the pH of the water after it contacts everything. This is the only sure fire way to know. You can also measure the pH at individual steps as you go, measure after adding to the kettle, after circulating through the pump, after contact with whatever type of chiller you have. This way you can narrow down where to focus.

I have not tried to measure the pH of my water before and after it enters my kettles. In the meantime, should I try this on it's own since I will not be brewing for a bit?

It was suggested earlier in the thread that "you won't be able to get a reliable reading by itself" of distilled water (they were referring to my sparge water). But I imagine what you're suggesting would be to see how much of a difference there is once it contacts my kettle, pump and hoses.

I will attempt to measure pH at each step next chance I get, but just to share my process:

Note: I don't sanitize on the hotside, except for my chiller.

1. Strike water (distilled) goes in the mash tun the night before with sugar and yeast (to deoxidize the water)
2. Morning of, strike water is recirculated and heated up to strike temp. Minerals/salts and lactic acid are added after 100°F
3. Grain is added and mash steps are followed, including pH reading 10 minutes in. Since I batch sparge, my sparge (distilled with minerals/salts) is my mash out and recirculated for 10 minutes at 168°
4. Boil kettle is brought to boiling temps and runs for 60 or 90 minutes.
5. I use an immersion chiller, which I DO sanitize in Star San (even though it's going into the boil kettle at 211°). At flame out I add the chiller and recirculate/whirlpool while chilling.
6. Stainless steel fermenter is sanitized---all interior surfaces covered and drained from the bottom. Wort is added to fermenter. Post boil pH is taken.

Once the beer is in the fermenter:

1. Mash tun is rinsed (grain is removed during the boil) and I use tap water to fill about 5 gallons. I add Alkaline brewery wash and recirculate for 30 minutes @ 150°F. I scrub the sides that aren't touched by the cleaner, or try to aim my return arm at the walls above the cleaner.
2. Wash is then transferred to the boil kettle and also recirculated for 30 minutes @ 150°.
3. (Old method) Cold water rinse the mash tun with tap water. Cold water rinse the boil kettle with tap water
4. (Old method) Pump, hoses and RIMS were hand rinsed

This process has slightly changed. Since my first post (Kolsch), it was recommended to use hot water rinse instead of cold water rinse, so I've switched to that. And since the second beer with high pH (Saison), I stopped hand rinsing the cleaner and started recirculated clean water through the system after using alkaline wash. The clean water is recirculated for 10-15 minutes at 150°F in both vessels.

The new clean water recirculation was not used pre-Saison and I incorporated it after that brew day. To be safe, the day after brewing, I ran another cleaning session and recirculated the brewery wash (slightly weaker blend) for 60 minutes in each kettle @ 150°. Then ran water @ 150° for 30 minutes in each kettle.

 

[Bobo1898]

UPDATE.

I ran a water test. Had some leftover distilled water (2 open and 1 closed) and decided to put it in the BK. I voided using the mash tun because my mash pH always appears accurate, and I didn't have time to complete this.

I tested my water before going into the BK. Two opened containers had a pH of 6.00/6.02 and the 3rd (unopened) was under 6 closer to 5.35 but I may have been impatient and didn't stir it again to get a more accurate reading. I mixed all three samples and got a pH of 5.68, so maybe that 3rd one was more acidic.

NOTE, these were equal parts in sample size but each water vessel had different volumes so this may not be the most accurate basis.

I poured all containers of water in the BK. Connected my pump and mash transfer hose (that goes to the BK, incase something was in that hose) and ran it for a bit. Then I stopped and connected my whirlpool hose and ran a whirlpool for 10 minutes. Then let it settle for 5 minutes. At no point did I do a boil or add heat. Everything was done at room temp.

I pulled a sample and the pH was 6.00/01.

I still had the mixed sample from earlier on the counter so I measured that again and it was 5.70, which was right around where it was before.

So there may be an increase of 0.30 after going through the BK system. The pump I use is the same pump for the mash so it's either the kettle or the hosing.

The only reason I say there "may be" an increase, is because the pH of distilled water is supposed to be around 6 and that's what I ended up with. But it's apparent in my brew day, that there's likely an increase. Unless, again, Fermax (which contains DAP) is the main reason. My post boil pH should be around 5.1 to 5.3. And I'm ending up with up to 0.65 increase on my brew days which is what doesn't make sense.

Next time I'll have to measure pH of my sparge water and my pre-boil volume.

Let's say I replace the hosing and I still have an increase. What can I do with the BK to resolve the issue? I've run alkaline cleaner through it thoroughly and rinsed it thoroughly but still ran into this issue.

One other factor that I haven't discussed is my steam condenser. This is a new addition to my brewhouse and I'm still dialing in the boil off percentage. My batch volumes have not been accurate because my boil off percentage hasn't been locked in. I've been ending up with more wort than expected. Maybe it's possible some of my tap water that is running through the steam condenser is getting back into my boil. But I would think that would cool down the wort. I'm running power at 35% and my wort temp is a consistent 211.4°F. If it was getting into the kettle, then that could also explain the pH increase. My tap water is around 7.5 or more.

I don't know. Maybe I should run the test again with only unopened containers, when I have time.

 

[marc1]

Distilled water is going to be far more susceptible to pH change from acids and bases than wort because there is nothing in pure water to buffer.
If the distilled water isn't changing then that's not it.

 

[Bassman2003]

Maybe something inside the pumps that needs to be cleaned out? Just guessing. Seems like this is pretty isolated to just your boil kettle and pumps/hoses. Not sure what is going on.