Quick Guides


SC-100A Quick Guide

SC-200 Quick Guide

SC-300 Quick Guide

SC-55 Quick Guide 

Troubleshooting pH issues on the SC-300 or SC-200



Frequently Asked Questions

General Questions

What is the Warranty/Return Policy?

Vinmetrica’s Return Policy:



Vinmetrica’s warranties and liabilities are:




How stable are the reagents?

The SO2 reagents and the pH/TA reagents are all warranted to last for 1 year, and we now give a use-by date that is 2 years from date of manufacture; in fact generally all SO2 and pH/TA reagents can be used several months beyond the use-by date. To ensure best stability, always store tightly capped and out of high temperatures and sunlight. And of course, the reagents will last much longer if not cross-contaminated with each other!

pH/TA Questions




Reconditioning and cleaning of pH electrodes

A. Clogging of the reference junction (most likely).

Unblocking the reference junction:

Cleaning the pH electrode’s glass membrane:

Meter test

13. Put the instrument in pH mode.

pH test with cream of tartar

c. Decant or filter the solution off the solids.





PH Variation with Temperature

Temperature °C Temperature °F pH
pH 3 buffer (phthalate) 0 32 2.91
5 41 2.912
10 50 2.918
15 59 2.919
20 68 2.924
25 77 2.932
30 86 2.936
35 95 2.944
40 104 2.953
45 113 2.962
50 122 2.973
55 131 2.984
60 140 2.998
pH 3.49 check solution 5 41 3.47
10 50 3.47
15 59 3.48
20 68 3.48
25 77 3.49
30 86 3.50
35 95 3.51
40 104 3.53
50 122 3.56
pH 4.01 reference solution 0 32 4.000
5 41 3.998
10 50 3.997
15 59 3.998
20 68 4.000
25 77 4.005
30 86 4.011
35 95 4.018
40 104 4.027
45 113 4.038
50 122 4.050
55 131 4.084
60 140 4.101
pH 7.00 reference solution 0 32 7.115
5 41 7.083
10 50 7.056
15 59 7.032
20 68 7.012
25 77 6.994
30 86 6.983
35 95 6.975
40 104 6.968
45 113 6.97
50 122 6.97
55 131 6.97
60 140 6.974




SO2 Questions






For Acid Solution Info Click here













Vinmetrica’s instruments correlate very well with other methods







To test the functioning of the instrument:










MLF Questions



Vinmetrica’s instruments correlate very well with other methods

What are possible interferences in the MLF assay?


What is the effect of temperature on the MLF assay?



Services Page FAQs

Vinmetrica Labs Quality Guarantee




Receiving your Shipping Supplies





• Cardboard box for returning the shipment
• Vinmetrica Labs Conical tube labels




6084 Corte Del Cedro, Suite 105

Carlsbad, CA 92011

Beverage Sample Shipping Preparation

Shipping Preparations for Beverage Samples









For Local Drop-off



6084 Corte Del Cedro, Suite 105

Carlsbad, CA 92011


Shipping Questions

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SC-100A & the SC-100

  • Accuracy: +/- 2 ppm Free or Total SO2


  • pH range: 1.0 to 13.
  • Accuracy: better than 0.02 pH unit.
  • Autocalibrate on pH 3.00, 4.01, 7.00, 10.00
  • Sensitivity: Detects down to 0.2 g/L Tartaric Acid





Data Sheet

SDS Sheets

SO2 Titrant
Acid Solution

pH7.00 Reference
pH4.01 Reference
TA Titrant


Boost Juice
Malic Acid

Reaction Buffer
Buffer Solution

YAN Neutralizer

ABV Developer
Calcium Hydroxide Neutralizer
ABV Oxidant
ABV Starch Indicator
ABV Titrant

Do you have a question that we haven’t answered here?
Not a problem, type it in below!

194 thoughts on “Support

  1. Per the manual for the SC-55 I should be getting a pressure reading within 5 seconds, and on the instructional videos the reading appears to occur immediately upon inserting the probe into the vial, but when I run the tests the meter continuously rises slowly (approx 1 kpa per second, not exact) for as long as I leave the probe inserted in the vial. The reading started at 0.55 kpa when initially inserted and rose to 1.7 kpa at approximately 2 minutes when I removed the probe, it was still rising. How long should I wait for a reading? Or why is it taking so long for the instrument to normalize?

    1. Brandon, it appears the CO2 is not coming out of solution as quickly as normally, which is typically 5 seconds or so. Try sharply rapping the vial on a hard surface 15-20 times before or even during the measurement to get the CO2 to equilibrate faster.

      1. Thanks for the quick response Rich, I’ll try again this evening!

      2. I reran the tests and have the same issue. I believe I have a faulty meter, with the 0.0 standard I ran the test for 2 minutes and the reading got up to 2.0 kpa and was continuing to rise.

  2. I recently purchased the SC-300 and forgot to screw on the pH storage bottle and probe was left to dry for a couple days. Is my pH probe ruined? If not, what should I do? Thanks in advance.

    1. Erick,
      Place the electrode back in the storage solution as soon as possible. It may come back to life. Soak the probe in the storage solution (but make sure this solution is clean and clear) for a few days and then try and calibrate it and see what happens. If you do not have fresh storage solution you can soak it in the pH 4.01 reference solution until you are able to get fresh solution. Let us know how it goes and if we can troubleshoot anything during the attempted calibration.

  3. I have the Vinmetrica SC 300. Can I leave both the pH probe and SO2 probe connected to the meter at all times or should I disconnect the probe I am not using.

    1. Michael,
      You can leave both probes connected to the meter if you want to. It will not harm anything.
      Let us know if you have any other questions.

  4. Do you recommend degassing the sample before measuring SO2 in sparkling wine? If not the volume may be wrong but is there a risk SO2 will disappear along with the CO2?

    1. Sven, Unless the wine is vigorously bubbling, you don’t need to worry about degassing prior to SO2 analysis. If the bubbling is sufficient to make measuring out 25 mL difficult to do accurately, then I would de-gas it by placing an aliquot in a container with minimal headspace. Shake strenuously and vent 3 or 4 times until no more gas evolves.

  5. I purchased a Vinmetrica 300 kit for measuring SO2 in August for my blueberry wine. I find the test shows my wine always has 2ppm (0.1ml titrant used) even though I keep adding more and more potassium metabisulphite.

    I am following a published recipe that calls for 150ppm prior to fermentation starting. After fermentation and 2 rackings I expect this number to decrease substantially, but now all the way down to essentially zero.

    6 November – added 0.45g powder diluted in some water and mixed well. 19L of blueberry wine. SO2 test says 2ppm.

    2 weeks later added another 0.45g of powder into 19L of wine. SO2 test still says 2ppm.

    1 December added 1g of powder into the same wine. Today the SO2 test still says just 2ppm.

    After the final 1g addition of metabisulphite I can actually smell the wine has changed, but the test still shows I have virtually no free SO2.

    I have tested several commercial red wines and got results of around 20ppm. I purchased a preservative free Shiraz and added enough powder to give 30ppm, and the SO2 test showed 20ppm a few days later. So the equipment works, but for some reason it shows completely erroneous results for blueberry wine.

    Is there something in blueberry wine that prevents the test working?

    1. Michal, I can’t think of anything that would prevent measuring levels of SO2 in your blueberry wine. Some fruit wines give erroneously high values due to reaction with ascorbic acid, but that is not the problem here since you’re getting lower than expected values. What can often occur is that wines with low SO2 develop aldehydes due to oxidation, and these can bind quite a bit of added SO2, requiring sometimes 3 times more SO2 to achieve the desired level than initially estimated.
      I suggest you take a small sample of your wine, say 100 mL, and add enough metabisulfite to bring it up to 100 or even 200 ppm. Then take 25 mL of this into the test. The remainder can be returned to the carboy if you want.
      If you still can’t measure anything then I will say I am stumped! Let us know what you find. -Rich

  6. HI, I have an SC-300. I cannot get my PH probe to calibrate under the regular or forced cal method. The estimates keep coming outside the acceptable ranges and so I keep getting a bad cal response. I tried most of the recommended fixes for this and nothing worker.I see I can buy a new PH probe from “More Beer ” for about $65. Do you provide a service where I can send it to you for repair instead of doing this?

    1. Tim,
      Thank you for contacting us. It sounds like you may need a firmware update at the very least. We can definitely check out your instrument and electrode together to see what might be going on. It is possible that you may need a new electrode but we will be able to make that determination here. At your convenience, please send in your unit and pH electrode (and SO2 electrode if you want us to just double check that too) to 6084 Corte Del Cedro Suite 105 Carlsbad, CA 92011 and please write RMA 609 somewhere on the box. Can you please let us know you return mailing address too? Once we check out your unit we will advise you on what we are seeing. If you need a new pH electrode, we have them in stock here. Turnaround time is typically 24-48 hours.
      Let us know if you have any questions.

  7. I recently purchased SO2 Titrant locally, lot # 400652. It does not have an expiry date on it so I am assuming that this is old stock!
    Wayne Meadows

    1. Wayne, there should be a “Use by” date just below the lot number. If that is missing, let us know. However that lot number should be from earlier this year, so the reagent should be good.

  8. Will not adding distilled water to aid in using a stirrer when checking TA using the sc30p throw off the results?

    1. David, adding 15-20 mL distilled water will not affect the results of a TA test. The acids you are titrating are those in the original 5 mL wine sample, and their total amount remains the same after dilution. It is true that their concentration in the vessel goes down, but you are not titrating the concentration; you are titrating the total amount.

      1. I titrated 5 ml of riesling 4 times, twice wine only and twice wine with 15 ml of distilled water and the results were different. The Distilled eater had a ph 0f 4.34. Wine only both tries the TA was 7.0 and with distilled water it was ~6.4 both times. The wine was stirred by hand and the wine plus H2o was with a stirrer.

        Any explanation or advice?

        Dave P

        1. Dave, If adding distilled water reduces the TA, then assuming no other sources of error, we would conclude that the water is partly titrating the wine. Pure distilled water should have a negligible TA value itself, as you can verify by just titrating 15 mL of your water alone (one drop of TA Titrant should take it over pH 8.2). If more than one drop of TA Titrant is needed to raise the pH above 8.2, then you probably have impure water. Given that the water’s pH is 4.34, it appears that it may not be that pure (distilled water in equilibrium with the CO2 in air typically has a pH above 5.0)
          However this would be expected to raise, rather than lower, the TA value. But for a start you might get fresh distilled (aka deionized) water.

          1. Thank you. The water is from a major retail outlet. I will test water as you suggested.

  9. I had a lot of trouble getting the SO2 probe to work, but I have to report, it is working now after going through all of the re-conditioning steps. It was the very last one… the several hour soak… that did the trick. Now, my SO2 readings are spot on with my calibration solution! I am actually surprised that this worked! I would suggest to anyone that is getting “1999” readings when they know they have SO2, they should just skip to the soak procedure. I’ve listed it below for reference….






  10. I have another question- In your revised SC-55 manual you state ‘Note: the following procedure is designed to be run at room temperature, preferably 78 °F (25 °C). Temperatures below about 73°F are not recommended, as test results may be less sensitive if temperatures are below this range’, yet in the MLF question and answer it is stated that 70 degrees +/- 3 degrees is desirable. Can you clarify which temperature gives the most reliable MLF results. Thanks.

    1. Ron, in the new version of the assay we recommend the 78F number in the manual. [BTW The manuals always contain the latest updates to any of our products.]

      We recognize that some people may need to run the assay at lower temperatures, which is fine, but highest sensitivity is obtained at the recommended temperature.

  11. I was reading over the SC-50 Quick Guide and on #5 procedure it references Boost juice. I know Boost juice is no longer used. How soon will you update the SC-50 Quick Guide as it is handy once I understand the whole process.
    Thanks, Ron Rudnick

    1. Ron,
      we plan to update many of our on-line materials over the next year. Our first priority is updating the videos. We hope to get to the quick guides soon after that.

  12. I haven’t used my Vinmetrica SC-300 for a few years and the storage solution in the pH electrode has dried up. Is the electrode still good? If so, what should I put in the bottle?

    1. Gene,
      You can try soaking it in fresh pH electrode storage solution for a day or two to try and bring it back to life. If you don’t have any then I would temporarily soak it in the pH 4.01 reference solution while you order and wait for some fresh solution. This has worked on electrodes in the past. The pH electrodes typically last about 2-3 years so if yours is significantly older than that it might just be best to get a new probe. Totally up to you. Let us know if you have any more questions.

  13. Is there information available which shows the performance differences in different firmware versions?

    What is the firmware performance difference between SC-300 with firmware version 3.1.2 & firmware version 3.2.d?

    There certainly is a difference in the SO2 probe connector! I also have 2 SC-200’s with different firmware. I know firmware version 2.0.2 will not show “Potential Mode”.

    SC-200 firmware 2.0.2 – Potential Mode not present
    SC-200 firmware 2.2.d – ????
    SC-300 firmware 3.1.2 – ????
    SC-300 firmware 3.2.d – ????

    Reading the SC-200 manual, I see firmware 3.1.2 was installed in the SC-200 at some point of production.
    Is this the same firmware 3.1.2 which is in my SC-300?


    Does each product have its own unique firmware numbering plan?

    1. Roger,
      Thank you for contacting us. All the firmware versions should function almost exactly the same while in regular analysis mode. The main difference between some of the older firmware versions and the newest one is the addition of the potential or mV (milli-volt) mode. On the SC-200 and SC-300s, this mode is indicated by a blinking pH LED. It comes after the pH mode and before the TA mode. You can cycle through using the MODE button to find it.

      SC-300s with the 3.1.2 firmware essentially have all the same functionality as SC-300s with the 3.2.d firmware. The only difference is that the 3.2.d firmware is for the newest version of the circuit board. The 3.1.2 version is the original version of the circuit board. I believe the circuit board change took place about 4 years ago.

      With the changes to the circuit board and the updates there were also some updates to the overall design in order to make testing easier for our customers. This included a change to the connector on the SO2 electrodes and subsequently the connector on the units for the SO2 electrode.

      SC-200s with 2.0.2 will not have potential mode but 2.2.d would have it. If you cycle through the modes on the instrument, this will be indicated by a blinking pH LED. This should happen after pH mode and before TA mode which hitting the MODE button to cycle through.

      That might be a typo in the manual. The SC-200s get the SC-200 firmware and the SC-300s get the SC-300 firmware. The main difference between the SC-200 firmware and the SC-300 firmware is that the SC-300 firmware has the code written on the circuit board for testing SO2, as the SC-300 is designed to test for SO2, pH and TA whereas the SC-200 is only designed to test for pH and TA.

      I hope this answered all of your questions. Let us know if we can help in any other way.

      Thank you

  14. Hi – I have the SC-300 (software 3.2.1) and I’m having trouble with the pH probe calibration. Values are coming in outside of the 0.5 pH dead band, and I’m trying to see if force calibration results in a good Cal (it’s been a couple years since I used the probe). I followed the instructions to get to the dead band setting (option 14) but my option 14 is SO2 baseline. As best as I can tell, all the other options are doing what they are supposed to, except this one. Am I missing something? Next step is to clean and refill the probe, but I’d rather skip that if possible – I noticed the pH 4 and 7 measured values (fresh solutions) are offset by a constant amount, so I’m not feeling like replacing the probe just yet. Any way to update the software? Thanks!

    1. Pip,
      Thank you for contacting us and thank you for trying to utilize the test mode features.

      It sounds like you may be operating off of the old guide for the test mode features but we should be able to get this resolved. Go back in to test mode and cycle through until you hear the loud beep (indicating the testing of the sound feature). Press the power button twice and the screen should scroll and say “Press Enter”. Go ahead and press enter and it should say Good Cal across the screen. Hold down the power button to exit out of test mode. That feature helps reset your pH settings back to their original factory settings. This wil help us diagnose what might be happening with your unit.

      Now try and calibrate your pH electrode. In 4.01, what does it read? In 7.00, what does it read? If it is showing up outside of the +/- 0.5 pH units then the unit will not calibrate. Since you have the newest version of the firmware, navigate to mV mode (this is the mode right after pH mode where the pH LED is blinking) Make sure your pH electrode is attached and put the probe in the 4.01 and the 7.00 solutions. What is the unit reading? Our rule of thumb is that, when in pH 7.0 reference solution, and with the unit in mV mode, the value on the screen needs to be 0 +/- 15 units. If your electrode is reading out of this range then the problem is most likely with your electrode and it should be replaced. The pH electrodes typically only last 2-3 years. If it is within this range then your electrode should calibrate okay. Sometimes if the electrode is older, it may need to be calibrated a few times to make sure that it holds its calibration. There is a white tag on the cord of the electrode with a month and year listed. What does it say? If its still not working, a phone call to our tech support line might be the best thing to do.

      It is always good, especially if the electrode hasn’t been used in a while, it would be good to clean the probe and replenish the solution that it is in. To clean the probe, soak it in 1N NaOH if you have some or even your TA Titrant, if not you can soak it in your SO2 Acid solution, for about 30 minutes. Make sure to do this in a separate container as particulates might comes off and you don’t want that in your solution bottles. You should also make sure that the solution in the pH electrode storage solution vial is clear and fresh.

      You mentioned an offset value? What are those values? Your software is the most up to date for your unit. About 4 years ago, we released a whole new version of the circuit board with an updated firmware but your firmware version is pretty similar to the firmware of the new version of the device.

      Let us know what other questions you have, or you can always call the tech support line for further assistance.

      Thank you

  15. I’m new to the testing process. When I am doing the SO2 test I start out with the reading below 50. When I add the titrant the meter eventually starts beeping and goes to 1999. I stop adding the titrant but it stays at 1999. Am I doing something wrong? Should I keep adding titrant? I read the meter should go above 50. I do have the electrode for the pH on the meter but I set the meter to the SO2 test.

    1. Bill,
      Thank you for your questions. The basic testing procedure is as follows:
      Testing for SO2: (assuming your meter is is newest model available, purchased within the last 3 years)
      1. Navigate to SO2 mode and attach your SO2 electrode. The meter should read 0.00, or at least under 50
      2. get your wine sample (25mL) and remember to sterilize your pipette before removing the sample from your barrel or carboy. We use Kirkland Vodka as our sterilant. Spray and wipe down the pipette then grab your sample. Place sample in 100mL beaker(provided).
      3. Add approx 2mL of the Acid Solution and 2mL of the Reactant solution to the beaker with your wine sample. Mix well
      4. Place your SO2 electrode in the solution.
      5. Fill your 5mL syringe or glass burette with SO2 Titrant and write down your starting volume, indicated on the side of the syringe. We usually fill ours all the way up to the 0.00 mark so it makes for some easy math at the end.
      6. Make sure your sample is mixing at all times during the test. Now, using your 5mL syringe or a glass burette, if you have one, very slowly add in your SO2 titrant, drop by drop until you are able to count 20 consecutive beeps on the instrument. Make sure the solution is stirring at all times until you have reached 20 consecutive beeps. This indicates that you have reached the endpoint of the titration and your test is done.
      7. Note your final volume on the syringe.
      8. Now take your final volume minus your initial volume (this is the amount of titrant you used for the test) and then multiply that value times 20. That will give you the ppm of SO2 in your wine sample.

      If you are in SO2 mode and your SO2 electrode is attached, and you are using your SO2 electrode for the testing then you should be okay. You can keep the pH electrode attached to your unit while testing. Some people keep both attached so that they do not lose one or the other.

      If you find that you are adding only one drop of SO2 titrant to the beaker before the instrument sounds off and goes to 1999, if may mean that you have no SO2 in your wine.

      There are videos available on our website that should help with a visual of what the test looks like.

      Let us know if you have any additional questions.

  16. Can I use distilled water rather than DI for TA test

    1. Warren,
      Distilled or DI water are okay to use. Make sure they are fresh too.
      Let us know if you have any questions.

  17. Hi,

    We specialize in fruit wines at our winery and I’ve noticed that my free SO2 reading with my peach wine is always >100ppm, which I find nearly impossible. Testing works fine on all of the other fruit wine varieties that we make, except for peach. I talked to someone that thought maybe it was the high vitamin C content of peaches giving a false positive.

    We use the SC-300 model. Any help would be greatly appreciated. Thank you.

    1. Jake, it is indeed possible that peach wine contains sufficient vitamin C to interfere. In that case you should run free SO2 by a different method. Aeration Oxidation is a good choice. We can run that test here in our Service lab if you like.
      Best regards,

      1. Thanks for the timely response, Rich. I will keep that in mind and be in contact if needed.


  18. I need to send in a sample of “grain on” whiskey mash to be tested for YAN. Is that test possible with a thin-ish flour mash?

  19. My so2 probe isn’t reading anything on my sc-300. In finished wine or fresh wine that i just put s02 in, it just always 0.0.
    The connection is tight an seems fine. Is there any solutions to this, or do i most likely just need a new probe?

    1. Matt, to test the SO2 function, follow this test:

    2. I am having a similar issue. I have a new probe, but the connection seems off. I often do not get a reading, but I if hold in metal connection from the probe to the SC-300 unit, I will start to get readings. But, I shouldn’t have to hold onto the probe connection for it to work. Any info is greatly appreciated.

      1. Jennifer,
        Did you try the test that was mentioned? Connect the electrode in SO2 mode and put it in about 20 mL of distilled water; add about 1 ml (half a bulb squeeze) of each of the acid solution and the reactant and swirl in the usual way keeping constant motion. The instrument may or may not indicate STOP as above. If it does not, add a drop of the SO2 Titrant solution. This should make the STOP condition occur. Is this what you were doing when you started holding on to the probe connection?

        If your instrument has an RCA (phono-style) connector for the SO2 probe, it may need physical adjustment to ensure good contact of both conductors (we can help explain how to do this over the phone). The older and newer versions have BNC (twist-lock) connectors don’t usually have this problem. Sometimes corrosion can occur at the connection and the connector may need to be cleaned off. You can contact our Tech Support line for further information and we can help you walk through these tests too. 760-494-0597 and select Tech Support.

  20. Hello, we purchased an SC-200 back in October from Presque Isle Wine when we went and picked up our fall juices. I must say it is one of the easiest and stable devices I have used in a long time. While we use it for ph and TA, we realize it would be better if we had bought the SC-300 as it has much more versatility and tests available like Free SO2 and YAN.
    Do you offer any kind of trade in policy on our SC-200? It is almost new and has only been used a few times. We would like to upgrade.

    Thank you,
    Kevin Croak
    Harmony Winery, Fishers Indiana

  21. Hi! My local store is suggesting I use a TA Titrant of 0,1 N or 0,2N (sodium hydroxide) as a replacement of the TA Titrant that came with my Vinmetrica SC-300 kit.
    Will I get the same results?

    1. Marcel,
      Thank you for contacting us. The 0.133N NaOH (TA Titrant) that we make is specifically designed to be used with our kit when testing your TA levels. You can use the 0.1N NaOH as a replacement for the TA Titrant however there will need to be adjustments made to your final calculations. You cannot use the simple equation listed at the end of the procedure (TA = 2 * V). You will need to use the longer equation listed above it and replace the 0.133N with the concentration of the NaOH solution that you use. This may blur your endpoint slightly so do take care when performing the titration and make sure to not overshoot the endpoint.
      Let us know if you have any questions.

  22. Good Morning,
    I have a question on the MLF 55 unit. How can I tell that my wine sample has boiled for 60 seconds. Should it bubble for 60 seconds? I’ve tried using the microwave on low and the wine never bubbles, but will kind of sputter violently once or twice. When it’s done it usually has 5ml left. I tried boiling water on the stove and using it as a water bath but the wine sample never seemed to boil, and when I finally pulled it out it was 3ml. I put a thermometer in the wine and when it hit 175F i timed 60 seconds and then pulled it out. I don’t trust the results of the MLF test because of this issue. As silly as this sounds it would be very helpful if you could post a video showing how to boil the wine or a bit more specific instructions on boiling the wine.

    If I pull all the chemicals out of the freezer can I reuse them again, i.e. can I pull them out of the freezer, let them come to room temperature, use what i need and then re-freeze them?


  23. A couple questions regarding pH/TA testing with your SC-200.
    1. I get a “Good CAL” with 4.0 & 7.0 buffers and get stable readings on wine samples. However, I can never get a stable pH reading on distilled water. Is it possible to test the pH of distilled water?
    2. When testing TA, I typically get a lower pH reading after adding 15 ml distilled water to the 5 ml wine sample (i.e. wine is 3.49 pH and wine with 15 ml water is 3.42). This looks like my distilled water may be slightly acidic (hence question #1 above). Does this skew my final TA results?
    FYI – I’m using super market distilled water which I boil prior to use and always top with argon gas.

    1. 1. It is possible to measure the pH of distilled water, but it’s tricky. In principle pure water has a pH of 7.00 at normal temperatures, but as atmospheric CO2 dissolves in the water the pH will drop slightly due to the formation of carbonic acid. In addition, most distilled water from the store, (which by the way is usually de-ionized, rather than distilled), may have very minor amounts of acidity or alkalinity that takes the pH away from 7.00. So even if you degas and boil, as you have, you may find the pH still not hitting 7.00 and in any case it will start changing immediately on exposure to air.
      However, the pH of your distilled water is unimportant for almost anything you want to do with it, because the water has negligible buffering ability. If you were to take 25 mL of it and do a TA titration for example, you will see that less than 1 drop of TA Titrant takes it to way above pH 9, so in essence it has no detectable acidity.

      2. The reason that the pH of wine drops on adding distilled water has nothing to do with the water or, up to a point, with the degree of dilution. Rather it has to do with the nature of the pH electrode and how it measures pH. pH is generally considered to be -log[H+], i.e., the negative logarithm, base 10, of the hydrogen ion concentration, but formally it is defined as -log(hydrogen ion activity). Activity a and concentration c are related but not identical: a = g x c where g is the “activity coefficient”. It is this coefficient that is changing as you dilute your wine, becoming closer to 1 with dilution. The pH electrode responds to hydrogen ion activity, rather than its concentration per se.
      Also, since wine is a fairly strongly buffered system (primarily by the tartaric acid/tartrate ions, and other acids present) you would have to dilute it over a thousand fold to change the hydrogen ion concentration.

      NB a.) to check your pH calibration, suspend about 1/8 tsp (0.5 g) of pure cream of tartar (aka potassium hydrogen tartrate) in 20 mL of water, stir to dissolve for 30 sec. Some crystals will remain. This saturated solution of cream of tartar has a standard pH at 25C of 3.56. I am good with 3.50 to 3.60. If not, try recalibrating. Make this fresh each day.
      b.) Be sure to always stir or swirl your solution when calibrating or measuring, i.e. do not let the electrode sit stagnant in the solution. You will get considerable errors in your pH measurements.
      Hope this is helpful.

      1. Richard,
        Thank you so much for the quick response and incredible detail. And, yes, your explanation is very helpful. GB

  24. When the YAN test is completed and the neutralizer is added does this make the YAN test safe to dump down the drain or do we still have to dispose of it in a special manner?

    1. Brian, the small amount of formaldehyde in a test is neutralized entirely by following the procedure in the manual, and since the pH of the solution should be less than 9 at that point, there should be no problem in sewering the test’s contents. However we can’t anticipate all local regulations, so you may want to check.

  25. The SC-300 kit comes w/ 2 burettes but not the stopcock. How do you use them w/o the stopcocks?

    1. Dan, the SC-300 kit comes with a 25 mL and 5 mL pipette but not a burette. These pipettes are for taking samples for SO2 and TA testing, respectively. For titration you use the syringes in the kit.
      We do supply a burette in the SC-300 Pro Kit, or you can get one in the Deluxe kit that comprises the extra items in the Pro Kit. You can also order just a burette if you like.
      All best,







  29. Hi








    1. Richard,

    Thanks again,
    Josh @ Tongue River Winery







  33. Good Afternoon,




      1. Rich,






    I’m very concerned at this point I have a bad analyzer!

    Please email me a way forward…


    1. Scott,



    Thank you,

    1. Jordan,


      Please let us know if you have any other questions.


      1. Hello Taylor,



        Thank you again for your help,



            Thank you,

          2. Yes this sounds like they are bad.

  36. With Reference your SC-300 Pro Kit
    1. What is the benefit of choosing
    either the 10 ml vs. 25 ml burette ?
    2. Once I order the SC-300 Pro Kit
    should I expect to receive it ?
    I live in North Hollywood, CA

    1. Bill,


      Let us know if you have any other questions.

  37. Hello Support;
    But I would like to get it repaired.
    Can I purchase a replacement display?
    Can I send it to you for repair?
    Please let me know how to proceed.
    Thank you

    1. Jim,




      1. Thank You!



    1. C Stewart,


      Please let us know if you have any questions.


  40. Hello,
    Thank you

    1. Ian,



    Ron Hanks
    Hillhaven Vineyard
    Baileyton, Tn.

    1. Ron,
      Thanks, Rich

      1. Hey Rich,

  42. Hi,

    SO2 titrant was added , the reading remained unchanged at 0.0.



    1. Thomas,

      (20 beep).
      All best,




    1. Jamie,
      -Rich Sportsman


    1. Martin,


    1. Aldo,

  49. I am beginning to feel old!
    You suggest storing the pH sensor in a 3M solution of KCl
    Is there a better answer?

    1. Trevor,



    1. Dale,




  51. Hello,

    Thanks for any advice on addition of O2 in small batches.


    1. Hi,



  53. Hello,



      1. Sir,

        defectuous as you stated in your answer.

        Greatings from Belgium



  55. Hi there!


    1. Hi Angelo,
      Happy Testing!


    1. Hi Ernest,


      Happy Testing!

  57. I don’t see any calibration videos or help on the 100A I need help.

    1. Hi Steve,


      Happy Testing!


    Thanks – Bill

    1. Bill,





    Mike G.

    1. Mike,



      Take Care




    Mike G.

    1. Mike,



      Thank you

      1. Hello Richard,
        I’m also interested in the alcohol measuring solution.
        Do you have an update on your progress?






    1. Linda,




    1. Ryan,




    1. Maryl,


  67. Vinmetrica sc-300//
    Thank you

    1. Ray,


  68. G’day Doc
    Regards Peter R.

    1. Peter,



      Take Care,

  69. Dear Mr. Sportsman,




    1. Beka




    2. Hi Beka,





    Liz Robson of Kingfishers’ Pool Vineyard. Leicestershire



      Our instruments measure in ppm.



    1. Hi Chris,


      Best Regards,
      Richard W.

  72. Is your M/L tester still in beta?



  74. I would like to chat over the phone if you get a chance

    Thanks Steve

    1. Steve,


  75. Thank you.




    1. Hi George,


      Best regards,
      Richard W.

  78. How does one measure total SO2 using your sulfite analyzers?

    1. Hi Richard,


      Best Regards,
      Richard W.


    1. Hi Michael,


      Best regards,
      Richard W.

  80. Hi,




    1. Hi Rob,


      Richard W.




        1. Hi Craig,





    1. Hi Mike,






    1. Graham,



    1. Joe,

      Thanks for posting!


  85. Please provide an example of the math for the sc-100 free…

    1. Terry,

      All best,



      Many thanks,



    1. Joe,
      Thanks for your comment.

  88. Mr. sportsman,











  89. are your meters still made in the usa?


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