i thought this was a chemicals and testing forum

[reisjdmd]

"the voice of one crying in the wilderness"
i thought i presented a legitimate issue that was of potential [pardon the pun] interestto all pH meter users. i guess i was wrong.
but consider, if you exclude internal electrical circuit failure, there are three reasonably common things that can go wrong with a pH metering system: buffer failure; electrode failure; battery problems. it is axiomatic in the use of a pH meter that you test the meter against an external standard before you test the unknown. sure, you adjust your meter to read pH 4.01 and pH 7.01, but how do you know that one of the three failure modes is not lurking? enter the external standard. simply measure the pH of a known solution, and if the reading is as predicted, you are set to go. i suggested a good and easy approach to this problem, and all i heard was the sound of crickets in a dark and empty auditorium.
now here is somthing to think about. you do not need the 2 commercial buffer solutions. all you need is two common and cheap and easy to prepare household products, that always have the same pH, and you can set your meter to those two points. for example, commercialdistilled water. if you buy from the same source,willprovide the same pH [about 7.05 by my estimate]. this eliminates one buffer. another easy one is to prepare a level1/4 teaspoon solution of pure tartaric acid crystals in 8 oz distilled water. this will give a reproducible pH reading somewhere in the mid 3's. there is nothing magic or necessary about using the commercial buffer solution. however, as with any system, an external standard is necessary. why did no-one bother to take me up on this? my idea is simple and would be helpful for all users of pH meters. hmmmmmm? i used to run portions of a big city hospital lab, and we always used an external standard. admittedly, human life might be considered more precious that wine, but are we, the people reading the chemical and testing site, not supposed to be interested in chemicals and testing?? or is this site fundamentally for dabblers? i would personally not take the chance of possibly screwing up a batch of wine by relying on a pH meter reading without checking against a known solution. perhaps others are not so compulsive. but after readingall of the compulsive posts about sterilization of equipment, i think people are concerned about doing the carefullittle things to maximize the chance of getting the best possible product. well, i just had to get that off of my chest at 3:30 am.

 

[uavwmn]

reis, whew......get some sleep!!!

 

[admiral]

I, at this point in my wine making obsession, am not using a pH meter.So, take what I am thinking with that caveat... I don't know anything other than what I learned in High School and college chemistry. Your suggested method seems plausible to me. Distilled water, uncontaminated, should have a trusted, repeatablepH. I am not so sure about the second solution.


"prepare a level1/4 teaspoon solution of pure tartaric acid crystals in 8 oz distilled water. this will give a reproducible pH reading somewhere in the mid 3's." How accurate must you be with a pH meter? My 1/4 teaspoon may be off, my tartaric acid crystals may age, I may be off in my measurement of distilled water.I don't think the second solution is repeatable. As I said I don't yet use a pH meter.Am I just checking to make sure that my meter is in the ballpark or am I testing with an expectation that my meter is "spot on" with the intention of adjusting my wine based upon my meter reading?


Just some thoughts and questions. Forgive me if they are dumb. I do hope you got some sleep after posting your note.

 

[reisjdmd]

admiral
excellent points. i am certain the distilled water would work. as for the lower pH standard [tartaric acid], if you always use the same 1/4 tsp measuringdevice, you should be ok. the acid crystals have a shelf life of at least 1/2 year, and probably a lot longer if stored properly. no worse than the hydroxide solution people use, and less caustic. i'm still sleepy. sorry about the rant.

 

[Waldo]

I always use the same "tongue" for checking mine and it works pretty good for me

 

[admiral]

Waldo! I was thinking the other day aboutthe Egyptians and the Greeks and their testing methods for their wine. No pH meters, no hydrometers, no SO2 calculators. How did they do it? It can't have been bad, or else they would have stopped. I know that this is a frequent topic here on the forum "the old ways" vs. "new fangled contraptions." I suppose there must be, as in most things, a "happy middle ground." I think I agree with you... who cares what the pH meter says, it has to taste right to me.

 

[Rocky_Top]

reisjdmd,
I missed the first post. I agree with your logic. I would however do a bunch of testing to findsome stable solutions. This could become a second hobby. Peter "the man" Zis a well respected chemist. I might enjoy arguing with him in private knowing that I am the fool but most will just take your post to heart then either take the high road or the low road. Being the risk taking rebel that I am I might try your idea.

 

[reisjdmd]

i agree with waldo about the tongue test. it's worked for about 9,000 years.i am only saying that if someone uses a pH meter, there is a correct way to use it. however, as we age [namely as i age] i notice my taste buds are getting weak. therefore, i would like toonce in a while compare my taste buds to a correct pH meter reading. what tastes like the correct acid to me may not work for younger people with healthier buds. plus, i have fun with the testing thing, even if it is largely unnecessary.

 

[smurfe]

I have 2 pH meters and various test kits and you know how I do it? Just like Waldo. I have found my tongue to be much more accurate than the meters. I only bought them cause I have to have the "bling"

Well seriously, I thought they were a vital piece of equipment and will at times drag them out. I always confirm any test with them with my tongue though.

 

[smurfe]

Also, I have tried reading your post a few times and am having a hard time deciphering it. Need some capitalization and paragraphs to break up the statements for easier reading and comprehension.

 

[PeterZ]

Just to note, I answered your question the first time you posted it.

 

[reisjdmd]

smurfe

the taste test works for my home-made. it is when i try to analyze why i do/do not like a commercial wine that i try to do the total acid and the pH test. because i test pH quite often, the cost of using fresh buffer, every time,goes up. the stuff is not cheap, unless you re-usean opened pack.all i am suggesting is that with the help of some forum members [the latent chemists], those of us that use pH meters can do so more cheaply.


iwas out of fresh buffer last weekend, so i could not do a reliable pH test. we had a bottle of some sort of california pinot noir. it was dreadful. i just knew i was going to get a headache, and i did [i had that headache when i wrote the long rant]. the wine tasted very "bitter/acidy", but the TA test reading was 0.25, which seems low. how do i explain this? perhaps my TA test was off and it would have been nice to have my pH meter on line as a backup.


i wonder if they added a ton of tannins or some other chemicals to give the wine a combination of acid/bitter taste? maybe paint thinner? was it a disguised retsina? yuck.