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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => EQUIPMENT - Making Cheese => Topic started by: awakephd on October 28, 2014, 07:27:27 PM

Title: Extech PH100 on the way ... now what else do I need?
Post by: awakephd on October 28, 2014, 07:27:27 PM
I am getting a PH100 meter for my birthday. :)

What else do I need to have on hand in order to use it? I assume I need 4 & 7 buffer solutions -- anybody got a recommendation?

Also, I see in the manual that I accessed on-line that the electrode has a limited life. How quickly does the electrode have to be replaced?

Thanks in advance!
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: Curdtastrophe on October 28, 2014, 08:49:34 PM
Good questions.
I anxiously awaiting the answers.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: ArnaudForestier on October 28, 2014, 09:59:28 PM
I get my 4 and 7 buffers from Get Culture (https://www.getculture.com/Buffer-solution.html).  Very reasonably priced, IMO.   

In my experience, the electrodes last quite awhile.  I went through several PH-100's initially, as the quality control was really rough - I think 6 or better, when I first got them.  But that was years ago and the customer service people never blinked, just shipped out a new one without questions asked.  The one I have now has been completely reliable. 
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: Spoons on October 28, 2014, 10:20:56 PM
Nice purchase awakephd!

You can buy 4 & 7 calibration juice at your local gardening store (specialty store, not the gardening section at Home Depot). It's really cheap. I get 500ml bottles for $5 and lasts about a year.

I also bought an electrode cleaning solution. I used it once when I bought my Exstik PH100 and haven't used it since. I don't feel like I need to use the cleaning solution as my calibrations are almost always on the dot. So for a hobbyist cheesemaker, I'd say the cleaning solution might not be worth it as long as you take good care of it.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: awakephd on October 29, 2014, 01:55:24 PM
Okay, here are three options from Amazon:

http://www.amazon.com/CL03-0213-1000-Buffer-Solution-4-00-0-02/dp/B00MX3KVG0/ref=sr_1_7?s=industrial&ie=UTF8&qid=1414590436&sr=1-7&keywords=ph+4+buffer (http://www.amazon.com/CL03-0213-1000-Buffer-Solution-4-00-0-02/dp/B00MX3KVG0/ref=sr_1_7?s=industrial&ie=UTF8&qid=1414590436&sr=1-7&keywords=ph+4+buffer)

(Price is right, but the shipping is a killer :o I think I'll pass!)

http://www.amazon.com/Atlas-Scientific-Calibration-Solution-10-0/dp/B0063MWYMQ/ref=sr_1_28?s=lawn-garden&ie=UTF8&qid=1414590530&sr=1-28&keywords=ph+4+buffer (http://www.amazon.com/Atlas-Scientific-Calibration-Solution-10-0/dp/B0063MWYMQ/ref=sr_1_28?s=lawn-garden&ie=UTF8&qid=1414590530&sr=1-28&keywords=ph+4+buffer)

(Includes all three reference points ... but it looks like I really only need 4 & 7)

http://www.amazon.com/General-Hydroponics-4-01-Calibration-Solution/dp/B004HE7W42/ref=sr_1_20?s=lawn-garden&ie=UTF8&qid=1414590493&sr=1-20&keywords=ph+4+buffer (http://www.amazon.com/General-Hydroponics-4-01-Calibration-Solution/dp/B004HE7W42/ref=sr_1_20?s=lawn-garden&ie=UTF8&qid=1414590493&sr=1-20&keywords=ph+4+buffer)

I'm leaning towards this last one, but I'm not sure how much it matters that the solution is 4.01 rather than 4.0 -- ??
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: awakephd on October 29, 2014, 06:19:08 PM
Update -- I bought 4.0 and 7.0 Atlas Scientific solutions, 8 oz each for around $8 each on Amazon.

As best I can tell, this unit does NOT use a special solution for storing the electrode, correct? (It says to keep the sponge in the cap soaked with ph 4 solution.)

When calibrating, should I put the electrode into the bottle of calibration solution, or pour a little of the calibration solution into a small cup? (May be a dumb question ...)
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: ArnaudForestier on October 29, 2014, 06:29:52 PM
I simply keep my meter submerged in a small vial of 4.0 buffer.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: Spoons on October 29, 2014, 11:16:51 PM
Update -- I bought 4.0 and 7.0 Atlas Scientific solutions, 8 oz each for around $8 each on Amazon.

As best I can tell, this unit does NOT use a special solution for storing the electrode, correct? (It says to keep the sponge in the cap soaked with ph 4 solution.)

When calibrating, should I put the electrode into the bottle of calibration solution, or pour a little of the calibration solution into a small cup? (May be a dumb question ...)

Yeah, just keep the sponge moist with ph 4 solution when storing. I store the meter upright, so the solution doesn't dry out in the sponge, maybe not necessary though. Sometimes I take out the sponge and rinse it and dry it before adding more ph 4, just to make sure the sponge doesn't get nasty.

Also, calibrate in tiny cups. You don't want to spoil your bottle content. Throw away the solution in the tiny cup afterwards.

VERY IMPORTANT: I just remembered this, Don't use distilled water to wipe the electrode.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: awakephd on October 30, 2014, 02:17:45 AM
Eric, say more about the distilled water -- IIRC, the manual says something about rinsing in tap water (?) -- do you do that, or ??
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: Spoons on October 30, 2014, 02:44:03 AM
I found the reference from an old thread. It's a comment from Linuxboy. You might not know him as he's been away on another project, but he's like the Walter White of home cheesemaking.

http://cheeseforum.org/forum/index.php/topic,6917.30.html (http://cheeseforum.org/forum/index.php/topic,6917.30.html)


I've been using tap water to rinse off and I wipe it dry with a paper towel. It hasn't damaged anything and the probe is still reliable one year and 20+ cheeses later.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: qdog1955 on October 30, 2014, 11:01:42 AM
Just got my Extech Friday -----with the 4.01 you described--hope that works------bet you have the same problem I have ----when and how to use the darn thing-----it seems I have to unlearn some of the things I have been doing and start experimenting--again.
  WE will be triumphant!!
By the way---I have seen some negative stuff about Extech-----having owned other equipment from them for years----I know they are a solid company, that backs their products----if you have any problems just don't wait to long to contact them.
Qdog 
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: awakephd on October 30, 2014, 02:18:10 PM
Thanks, Eric -- very helpful! Yes, I have seen Linuxboy's posts; as I recall, he was announcing that he would have to step away from the forum for a while just about the time that I started participating.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: ArnaudForestier on October 30, 2014, 04:14:18 PM
Awake, I'm sure this isn't news to you, so please forgive the intrusion to your thread.  But in case other, less experienced people might find this useful, here's my $.02 on Pav and others. 

Dig through his stuff.  Pav (Linuxboy) has been the single greatest source of help and information for me.  He's unqualifiedly the most knowledgeable person I've met, and that goes way beyond cheesemaking and dairy science.  There are a few others - in no intended order, as they've all been so helpful: 

Alpkäserei, too, has played a pivotal role in my approach to alpine cheesemaking (my singular love, really). It's Alp and Pav who together lit my fire in embracing a traditional approach to making the hard alpines - whey cultures (as opposed to pure, bought culture strains), traditional methods, making one's own rennet, etc.  Really, embracing the traditions codified since at least the time of Caesar, traditions that have stood the test of time in making truly extraordinary alpine cheeses (Alp's love is justifiably all things Swiss, and mine, all things Savoie) almost in defiance of the incessant press of modernity.

Jim Wallace is an expert in all things Alpine as well, and he's got tremendous information to sift through (check out his thoughts here, his recipes and/or classes on New England Cheesemaking.com, or his blog (http://cheesetravels.blogspot.com/2009/09/up-into-mountains-sept-4-2009.html)). 

Also, for what it's worth, I've learned tons from Francois (in particular, cave construction, pyrenees tomme making, thoughts on Beaufort, alpine affinage, semi-firm makes and cultures generally), and Sailor as well.  Sailor is a trained microbiologist.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: tally on October 30, 2014, 07:43:06 PM
I found a post by linuxboy very helpful when my Extech was acting a little wonky. I forgot to bookmark it but as I recall it was around 2011. I found it when I typed in "pH meter" in the search box here on the forum. My readings were all over the place. Turns out my probe needed a good cleaning. I soaked it in contact lens cleaner, then vinegar then washed it in hot soapy water. Problem solved and it's worked perfectly since. Mostly the pH 4 buffer solution works well, but once in a while deposits build up (protein, fat and salts) that need to be cleaned off.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: awakephd on November 17, 2014, 05:51:33 PM
Thanks, Arnaud and Tally -- somehow I had missed these replies until now!

Qdog, I am indeed a bit unsure how to use the thing, but I am having fun experimenting. For now, I am continuing to follow the recipe as I otherwise would, but trying to check PH along the way to see how it changes.

Which brings up a question: When I check PH with this, I am not entirely sure of the reading I am getting. It starts out immediately with a flashing reading, which typically rises over a few seconds, and then the reading stops flashing. But the reading continues to rise a bit if I continue to hold it in place. Which reading should I be trusting -- presumably the one when it stops flashing?? (This is something the very limited manual does not seem to address!)

And a follow-up question, to which I think I know at least one possible answer: where should I be looking for PH targets? I think, based on others' posts, that one answer is Giancallis Caldwell's book, which I am anxious to get. Maybe that will be a Christmas present ... but are there other places I should be looking?
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: Spoons on November 17, 2014, 05:58:34 PM
Yeah, the Extech 100 does need some getting used to. When I first got it, the readings were all over the place. So I took out the battery, took out the probe, waited a minute, installed the probe and then installed the battery. It's been working fine since.

About the readings going up or down even after it finishes blinking: Turn off the meter. Insert the probe in the whey. Wait 30 seconds for the probe to get used to the whey's temperature. Turn the meter on. The readings are usually much more stable this way.

Caldwell has PH targets in her books. Perter Dixon does too. I really like both these cheesemakers recipes!
http://www.dairyfoodsconsulting.com/recipes.shtml (http://www.dairyfoodsconsulting.com/recipes.shtml)
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: ArnaudForestier on November 17, 2014, 06:09:49 PM
Quote
Which reading should I be trusting -- presumably the one when it stops flashing?? (This is something the very limited manual does not seem to address!)

Yep, that's when I go with it too.  I may be overly cautious, but I also dual-calibrate each time I sample.  It might be because I had some earlier issues with these meters, that have since been rectified, but it's now habit. 

Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: tally on November 17, 2014, 06:42:03 PM
Good question on the meter, Awakephd. My meter does the same flashing, climbing. I've taken to waiting until the numbers don't change at all for several seconds, but I don't know if that's correct. Any feed back from you old cheese heads out there? When is the correct pH reached?
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: ArnaudForestier on November 17, 2014, 06:53:36 PM
Hi Laura - I can only give you my experience, and that's when I do it too - like you and Awake.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: qdog1955 on November 18, 2014, 11:07:55 AM
Awake---seems you and I really are in the same boat----had the same problem, with meter keeps changing-----the temp. seemed to be the problem, so I used a little electric hot plate, used to keep a cup of coffee warm (it never did keep the coffee hot) but it keeps the solution about 90 degrees----I turn off the meter between reads and place it in the mug with some 4.0----when I use it----the read only takes about 20 seconds or so---it seems to work. Here again, don't have enough experience to be exactly sure---but might be worth a try.
Qdog
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: ArnaudForestier on November 18, 2014, 01:01:11 PM
I've never had much of an issue with temperature and reading creep.  Not perfect, but at least over the last couple of years (I had many of them fail, but that was several years ago now), the ATC works really well.  Actually, have to say, the meter works great, now.  Several seconds of reading, then a steady state, then a couple of points up or down, but the steady read is reasonable, given my expected target and what I know I'm doing in the vat.
Title: Re: Extech PH100 on the way ... now what else do I need?
Post by: awakephd on November 18, 2014, 06:56:27 PM
About the readings going up or down even after it finishes blinking: Turn off the meter. Insert the probe in the whey. Wait 30 seconds for the probe to get used to the whey's temperature. Turn the meter on. The readings are usually much more stable this way.

A great suggestion! I shall implement it as soon as I make my next cheese (hopefully this coming weekend). I had wondered if the problem had to do with temperature compensation.

AC4U!