Do you trust your ph meter?

[Cherry Yidaki]

They always seem a bit suspect to me and tend to go squirrely for no good reason. Just today I was checking a wash and found the readings "weird," so I checked the meter against the reference solutions and saw it was +3 points off to the high side. So, I got my little screwdriver out and tried to adjust it back, but it's done this enough times that the screw adjustment has bottomed out.

Which leaves me wondering if it went bad all of a sudden, or if the badness crept in, little by little, and I never have had a really accurate reading from it.

I'm kind of color blind, so the strips aren't particularly useful. I think there has been booze being produced far longer than there has been a means to accurately deduce acidity levels. I'm starting to wonder if I want to mess with a ph meter at all.

What do the rest of you do, re: ph measuring?

[chill]

I check only if it seems to have stalled. Usually I use a ph buffer so checking ph is needless. I have a ph meter, I don't recall ever using it...

[Voddy]

I have an electronic pH meter and was told firmly to clean the bulb and let it rest in pH7.0 water and it has never failed me yet despite being sold on offer at just £7.00

The guy said that to allow a film of heavily biased pH to dry on the bulb will eventually 'stain' the bulb permanently giving off readings.

Tosh? I don't know. But that's what I was told. It could be that I'm just lucky with my kit.

[Icefever]

This question was asked on a beer forum awhile back, the general consensus was that to trust a PH meter you had to spend big bucks. Also one of the guys on there used them in his work and said that they had to reset the meter every time before using against a known Ph solution.
I've got both the paper strip and the liquid tester, but even these differ
and if you can't see the change in colour..

I've thought about buying one of the cheaper ones off t'internet, then think no I'll spend my money on other things.

We may be lucky when it comes to mains water, what comes out of our tap is ok to drink taste wise, I travel the UK and some of the water that I try to drink
it must come strait from the local swimming pool..

I did email our water company and asked for a printout, the PH was middle for diddle, so I leave well alone.

[Easydrinker]

I tried drying the bulb on my 'pen' tester last week before putting it away and broke it!
Replacement was delivered today.
I also have cheap litmus strips,and they seem to agree with it.
My neighbour,a chemical engineer,laughs at the quality of my ph testing gear,and rambles on about 'narrow range' testing.
It makes it seem that I am being scientific,and so I continue.
I feel good,but it probably makes no difference.
I get the same results as I did before testing for ph.
Robert.

[Cherry Yidaki]

herm.... This one http://www.amazon.com/Hanna-Instruments-Electrode-Batteries-Resolution/dp/B0085WOIMQ/ref=sr_1_15?ie=UTF8&qid=1389143541&sr=8-15&keywords=ph+meter is what I've been using. It has a black rubber cap that I fill with the storage solution after every use (after cleaning it, of course) so it shouldn't be drying out.

I would imagine the water company keeps the local supply withing certain parameters. I know every time I've checked the tapwater it's been around 7.9. Given that, would a buffer need to take into account my "base" value when being concocted. I need to read up on that again.

But, like you, Easydrinker, I like feeling "sciency" about my stuff. Spent a career in the medical field and always found the gadgetry and diagnotic tools fascinating.

[Almanac]

I use a digital pH meter and a calibration solution. It took me a while to find a lab supplies company that would sell single bottles of the calibration solution but I test mine once a month and over the past 18 months I've only had to adjust the meter once in that time

[Cherry Yidaki]

Thanks for all the responses.

aidanmac - So, you use a ph buffer, I've read. Do you put that in:

A) Before adjusting your 5.2 SG wash to 5.5 ph
B) After adjusting your 5.2 SG wash to 5.5 ph
C) Instead of adjusting your 5.2 SG wash to 5.5 ph

Thanks. I asked another question in your red lentil string, too, if you'd be so kind.

[chill]

I don't think that Aidan uses a ph buffer now. I still do and use it instead of measuring ph. Why bother measuring what you are going to change?

[Cherry Yidaki]

chill: you said - Why bother measuring what you are going to change?

Something about that logic seems elusive...

So, when you create your buffer, do you take into account your source water's likely ph and hedge to one side or the other? Like, say, you know your water normal has a ph of 7.8, would you add a bit more acid, or a bit less base, to compensate and hopefully get you in the 5-ish sweet spot?

[chill]

Short answer: yes. There is a formula that you can use (ask Google), or you can trial and error it until you get the result that you want. You can guess which one I used.

Chuck

[Cherry Yidaki]

I can guess that in one try.

So, for curiosity's sake, what is your, personal buffer recipe? And, if you know it, your water's ph?

Thanks, and I promise I won't bring it up again. Fer sure.

[chill]

It looks like 6.5 according to my hyper-accurate Chinese paper strips. My formula is 192g of Citric Acid and 252g of Baking Soda. Stir very well (dry!) and separate into three batches. Each is enough for 25L.

Chuck

[Phantom]

See I like to read stuff and mostly follow the point......

Surely pH is only a problem if something isn't playing right in the ferment........

Plus some of the numbers posted here seem a bit weird too......

Having made meads I've had to be aware of pH issues, doubly so as I'm in a hard water/high calcium area.

So as I might either make both, I have a pH meter (a cheap one as it doesn't need to be critically accurate).

Cherry"s mention of 7.8 pH water ? Damn, that's almost lime wash ........ my tap water is about 7.01 pH and is considered moderately high calcium, which makes for a slightly harsh tasting spirit and a flavour issue that I can't explain or describe well in my meads.

So knowing that I also remove one of the issues (the calcium content) by using RO water.

Now with my meads and sugar turbo's, they're both quite similar in make up apart from the non-sugar elements in honey. My sugar washes measure about 1.080-1.090 the meads are higher.

Once the yeast is pitched, the ferments will measure about the mid 3.X pH which is generally about the sweet spot for the yeast.

Between the presence of dissolved CO2 as carbonic acid and the strangeness of gluconic acid changing (delta-glucono lactone etc) backward and forward the pH in such unbuffered solutions can swing quite wildly but is only an issue if it drops below 3.0 pH.

Should the ferment slow significantly or stall, then I just hit it with a pH raising solution i.e. potassium carbonate (found to affect the flavours the least).

Now I appreciate there's a fair bit of science behind that but I don't pretend to understand it all. I just go with the numbers.....

I just use commercially available calibration fluid to check my meter either 7.01 pH fluid for checking water or 4.01 pH fluid for when checking must or washes.......

So the point of the argument isn't so much about the meter, but about the calibration fluid.....

That way surely the measurements are accurate enough for what we need........

Oh and the hanna brand meter linked earlier, is, as I understand it, a reasonably good quality one.....

[Almanac]

+1 what P said.

I chased the pH ghost for a while in the belief that I had a problem to solve...but I was wrong.

The recipe I was using, TPW, just didn't work for me. To this day I don't know why and I couldn't care less. The pH would dive rapidly below 3 and the wash would stall every time. I bought in Sodium Citrate Trihydrate and Citric Acid to construct an appropriate buffer and it worked...more or less but there was a lot of messing around with buffer strengths and having to measure and weigh the ingredients for each wash....

Then a good friend suggested that, seeing as I was only trying to make neutral spirits, I should try a simpler recipe - enter the Lentil Wash and that has become my standard for making neutral spirits.

Because my water comes from my private well I do check the pH because it can vary depending on the season and rainfall etc.. But once it's in the 5s that's just fine.

pH will decrease as the ferment progresses and that's just natural. The real trick is to start a wash at a point where it will have sufficient time to ferment out before the pH drops so low it puts the yeast cells to sleep and for most purposes the mid 5s seems to work once you're not adding anything that's going to directly affect the pH by itself like adding an acid or base component such as Citric Acid or Sodium Bicarbonate.

Check your recipe for anything that might have an affect on the wash pH such as Tomato Paste! If you live in an area with limescale in your water this will probably work fine but if, like me, you live in an area where there's zero lime in the water Tomato Paste will kill your wash

AM