Frequently Asked Questions


What is the Warranty/Return Policy?

Vinmetrica’s Return Policy:

A restocking fee of 15% will be charged on all returns made within 45 days of shipment, unless items are returned for repair or warranty service. ALL returns must be sent with a valid RMA number which we will assign to your item after you contact us.

If you believe that you have defective equipment we will work with you to resolve the issue and repair or replace once a diagnosis has been completed. Please contact or call +1 760 494 0597 and select Tech Support, with any questions.

Vinmetrica’s warranties and liabilities are:

1. Instruments, electrodes and non-reagent accessories are warranted against defects in workmanship for 24 months from date of purchase. The reagents are warranted to perform as described in the manual up until any stated expiration or “use-by” date, or 6 months after purchase, whichever is later. THE WARRANTIES IN THESE TERMS AND CONDITIONS ARE IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT, OR FITNESS FOR A PARTICULAR PURPOSE, SAID WARRANTIES BEING EXPRESSLY DISCLAIMED.

2. Buyer agrees that its sole and exclusive remedy against Vinmetrica shall be limited to the repair and replacement of Materials or parts of Materials, provided Vinmetrica is promptly notified in writing, prior to the expiration of the warranty period specified above, of any defect. Vinmetrica’s liability for any damages due Buyer shall be limited to the purchase price of the Materials.


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

I want to use the SC-200 to test for an acid other than Tartaric Acid. Can I test the pH and Lactic Acid level in beer or other beverages?
Yes! The SC-200 or SC-300 can be used to test beer, cider or any other beverages, you just need to know what Acid you’re testing for.
For example, you can do pH and TA on beer with the SC-200 or SC-300.
The pH is independent of the beverage or whatever solution it’s measuring.
The TA is also; it’s just a matter of how you calculate the final answer.   Wine TA is usually reported as tartaric acid but the titration actually measures acidity as equivalents per liter (eq/L). If you assume the acid is mostly tartaric (true for wine) then you use the conversion factor for tartaric acid (75), as we do in our kit.
For measuring the acidity levels in a sour beer you would use the factor for lactic acid (90). So you could just convert as:          g/L lactic = 90/75 * g/L tartaric. To determine the conversion factor for the acid you are looking for, simply look up the molecular weight of the acid. The molecular weight of Lactic Acid is 90, so that is why we used it in the equation above.

What should I do if my pH electrode is difficult to calibrate, or is acting sluggish/erratic?

NOTE: in most cases, calibration problems can be addressed by steps 1-6 below. If your electrode is slow or showing numbers way out of range, try the meter test FIRST (steps 13-16 below). The reconditioning steps (7 – 12) should not normally be needed on an electrode that is less than 6 months old.

1. Be sure your electrode has been stored at least 24 hours in a proper electrode storage solution (Vinmetrica’s product is 3M potassium chloride in 10 mM potassium hydrogen phthalate; other similar products may be used). The entire bottom 1 inch of the electrode needs to have been submerged for at least 24 hours. If this has NOT happened, wait until it has!
2. IMPORTANT! Always stir or gently agitate the solution when using the pH electrode; letting it sit static will cause drift and inaccurate readings!
3. When calibrating your pH electrode, remember that the displayed pH may not be correct until AFTER you press ENTER, and the “Good Cal” message finishes scrolling.
4. If the instrument signals stable pH (i.e., the Cal LED is flashing) but displays “Bad Cal” after pressing ENTER, try putting it flat on the table; when the next stable pH is signaled, press the ENTER button quickly without handling the instrument. Sometimes the instrument may pick up noise from its environment, particularly if you handle it at the last second, while it’s trying to achieve a stable reading.
5. If values appear to drift, leave the electrode in the pH 4.01 reference solution for 30 minutes.
6. If you intend to read pH values in samples that are at a different temperature than ambient, it’s best to have your reference solutions at that temperature also before calibrating.
7. You can restore the pH calibration and bias (DAC setting) values to factory defaults in Test Mode (see Appendix A, Section 13 in your manual). Contact tech support if you have questions beyond this.

Reconditioning and cleaning of pH electrodes

Note: before you try the procedures that follow in steps 8-12, try the simple step of soaking the electrode in your pH 4.01 reference solution for about 1 hour, then try to calibrate. Sometimes this is all that’s needed!
Even in normal use and storage, performance of pH electrodes may show deterioration over time, which typically shows up as noisy, erratic or sluggish electrode readings, and/or difficulty calibrating. Assuming the meter itself is working (see “Meter test” below), then there are two main causes for this:
A. Clogging of the reference junction (most likely).
B. Fouling of the glass membrane (happens occasionally, or after prolonged service).
The following procedures will often provide renewed stability and pH sensitivity. If the electrode cannot be restored by one of these methods, it needs to be replaced.

Unblocking the reference junction:
The reference electrode junction is usually the problem when the electrode can’t calibrate in its expected ranges. This junction is a fine-pored frit that allows electrical contact of a reference electrode with the solution being tested. It can become clogged over time.
8. Soak electrode in hot (NOT boiling!) water, about 60 °C, for 5 – 10 mins. Allow to cool to room temperature then place in pH 4 reference solution for 5 minutes. Try to recalibrate. If this does not work, try the next step.
9. Place electrode in electrode storage solution (from Vinmetrica, or 3M KCl with optionally added 0.01M potassium acid phthalate, KHP) at 60 °C and allow electrode and solution to cool to room temperature, then place in pH 4 reference solution for 5 minutes. Try to recalibrate. If this does not work, try the next step.
10. Soak in 0.1M HCl (note: this can be made by diluting 1 mL of the SO2 Acid Solution with 20 mL DI water) or HNO3 for 1 hour. Rinse with DI water, then place in pH 4 reference solution for 5 minutes. Try to recalibrate. If this does not work, try the next step.
11. Soak in 1:10 dilution of bleach in a 0.1 – 0.05 % solution of liquid detergent in hot water with vigorous stirring for 15 mins. Rinse with DI water, then place in pH 4 reference solution for 5 minutes. Try to recalibrate.

Cleaning the pH electrode’s glass membrane:
The glass bulb is a thin membrane of a special kind of glass that actually does the job of responding to the pH of the solution. It can sometimes become dirty and poorly responsive.
12. Immerse electrode tip in 0.1M HCl (see above for how to make) for about 15 secs., rinse with distilled water, then immerse in 0.1M NaOH (you can use a little of your TA Titrant for this) for another 15 sec. Cycle the electrode through these solutions several times (rinsing with DI water in between), then rinse and check for performance in pH buffer 4.00 and 7.00.

Meter test

You want to be sure that the instrument is responding correctly. A quick test is to simply short out the electrode connector:
13. Put the instrument in pH mode.
14. Remove the electrode to expose the BNC connector at the back of the instrument. Short out the terminals on the connector, using a paper clip or similar metal piece to touch the center pin of the connector to its outer metal sheath.
15. With the input shorted out, the reading should be pH 7.00 +/- 0.5. If out of this range, the meter is probably bad. Contact us.
16. Bear in mind that this test is not 100% fool-proof (the instrument might still have trouble reading pH values different from 7.00), but generally if this test passes, it is much more likely to be an electrode problem.

pH test with cream of tartar

A quick way to check your calibration and pH accuracy is to measure the pH of a saturated solution of cream of tartar which has a pH of 3.56 at 25 degrees celsius:
a. Get pure cream of tartar (grocery store stuff is fine, provided it’s pure), or even better is reagent grade potassium hydrogen tartrate, also known as potassium acid tartrate or potassium bitartrate. Call it KHT for short.
b. Place about 1/4 teaspoon of KHT in 20 mL of distilled water. Mix well for about 30 seconds. You want to be sure the solution is saturated, i.e., everything that can dissolve, has dissolved. There should be some undissolved solid left.
c. Decant or filter the solution off the solids.
d. This solution has a standard pH of 3.56 at 25 degrees C (78 degrees F). It should be within 0.02 pH of this value at temperatures from 20 to 30 degrees Celsius. Discard after 24 hours.

How much does pH measured with the SC-200 & SC-300 vary with temperature?

There is very little variance of the pH measurement of wine if you are operating within plus or minus 27 degrees F (+/- 15°C) of room temperature, 77° F. The table below will let you know what are typical readings from the pH meter using our reference solutions or other buffers at different temperatures. If you operate the pH meter close to room temperature, 77° F (approximately 25°C) , with the wine sample and the reference solutions also close to room temperature, you should have acceptably accurate measurements with a variance +/- 0.02 pH units.

If you are operating in outdoor conditions or in a cold cellar, the chart below should let you know how much variance is to be expected regarding pH buffers and our pH 4 and 7 reference solutions as well. Since most wines fall within a pH range 3.0 to 4.0, you can roughly approximate the variance in pH to be similar to a pH 3 buffer, a pH 3.49 check solution (50 mM sodium diglycolate), and the pH 4.01 reference solution provided with the SC-200 and SC-300. Even a change in temperature of +/- 27°F from room temperature doesn’t change the pH more than +/- 0.03 pH units with the three solutions mentioned above, so unless you are operating below 50°F or above 104°F, the pH measurements accuracy due to temperature variation is very close to the error of the instrument (+/- 0.02 pH).


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


Help! What do I do if my pH electrode was attached to my SC-300 when in SO2 mode? Is my pH electrode broken?

No, don’t worry, your pH meter should still work. To fix it, leave your pH electrode in the pH 4 calibration solution for an hour and it should return to normal function. Enabling SO2 mode with the pH electrode attached could cause the pH electrode to wear out more quickly. Because of its design, SO2 mode cannot be accessed unless you press ‘enter’ after pressing the ‘mode’ button, this is another safeguard we installed to prevent this from becoming a problem.

SO2 Questions

I added the right amount of sulfite to my wine but the numbers are still low!

This is a common occurrence with several explanations, any or all of which may be happening:

  1. Make sure you are using fresh sulfite powder. Potassium metabisulfite degrades over time and that stuff you bought 2 years ago is probably bad now!
  2. Make sure that you stir your wine thoroughly when you add sulfite. If you pour a 10% solution of KMBS into your wine, it sinks like a battleship! A sample taken off the top will read low unless the wine is stirred.
  3. A significant portion of the sulfite you added may have ended up ‘bound’, particularly if your free SO2 was very low to begin with. This bound SO2 does not show up when you measure free SO2, and it is not protecting your wine. You will need to add more sulfite until your free SO2 comes up to the right level. Sometimes you must add 2 or even 3 times more sulfite than you first calculated.

What’s the difference between the SC-100A and the SC-100?

The SC-100A is simply a new body style using the components found in the SC-200 and SC-300. It functions exactly the same, with only the audible buzzer slightly different in its tone. The reagent kits for the SC-100 and SC-100A are the same. While we no longer sell the SC-100, we still support it, and will continue to do so.

For Acid Solution Info Click here

The Acid solution is 2M (2N) Hydrochloric Acid (HCl) (6% W/W). The solution is considered a hazardous material. For the international units or reagents, we have found an acceptable method of shipping with FedEx. This is in compliance with international shipping standards. We can now ship the acid solution internationally. The acid solution will arrive in 1 ounce bottles but will function the same. This restriction also applies to shipments destined for Alaska and Hawaii.


This information does not apply to international shipments to Canada or Mexico.


If you are interested in purchasing the large 450 mL volume bottles of the acid solution or the SC-100 & SC-300 SO2 Reagent set, please email for more information.


ALWAYS use caution when dispensing or diluting the acid solution. It is not terribly dangerous but ALWAYS use laboratory protective eyewear, gloves and preferably long sleeves, pants and closed toed shoes. If you do happen to get it on you flush with large amounts of water. If the acid solution gets into the eye, walk over to a sink and flush water in your eye for 10-15 minutes, call 911 if there is any concern and consult a poison control agency, in the US call 1-800-222-1222. For poison control in other countries check out this website. Poison Centers.


Another option for getting a large amount of the acid solution would be to order 2M HCl from Sigma Aldrich, click here. You can order a liter of 2M HCl through them, while on the website it claims it is 22.70 per liter, there is also an added $15 – 25 hazardous materials charge and then the shipping cost on top of that. So the cost is from $37.70 – $47.70 plus shipping. At Vinmetrica, each SO2 analyzer kit has 100 mL of the 2M HCl Acid reagent which is good for about 50 tests, so you can imagine that you will not run out of the liter quantity anytime soon. HCl almost never deteriorates (as long as it is not cross-contaminated and is stored and sealed properly).


How does the Vinmetrica SC-100 (or SC-300) compare to other methods?

Vinmetrica’s SC-100 (and SC-300) gives results that are right in line with aeration oxidation (AO) and segmented flow analysis:

Vinmetrica’s instruments correlate very well with other methods

Also check out Dan Pambianchi’s article “Benchmarking of SO2 Analysis Instruments and Methods” on the Home Winemaking Resources page of the Techniques in Home Winemaking website: of SO2 Analysis Instruments and Methods.pdf

My SC-100 tells me the battery has only 8.5 volts, but I just put a fresh 9V battery in. What gives?

The SC-100 has a voltage drop of about 0.5 V , so a good battery will generally read about 8.5V. In fact the SC-100 will still function when the battery is well below 8V, though we recommend replacing the battery when the battery check warns you with its red LED and buzzer.

I’m getting strange results in SO2 mode; how do I know if my instrument is working correctly?

For SO2 measurements with the SC-300 or the SC-100A, there are several quick tests you can do to make sure the instrument is not faulty.

First, if your instrument does not have the latest firmware version 1.1.2, 3.1.2, or 3.2.d, we recommend that you always start with the electrode disconnected. After powering on the instrument (and, on the SC-300, pressing ENTER to confirm SO2 mode), then connect the SO2 electrode. This avoids incorrect background settings that may make the instrument appear to be insensitive or unresponsive. To determine which firmware version you have, go into Test Mode (see Appendix A in your manual, or above in this section of the Website)

To test the functioning of the instrument:

1. Be sure the battery is good per the manual’s instructions.

2. Remove the electrode to expose the BNC connector at the back of the instrument. Turn on the instrument and select SO2 mode. Short out the terminals on the connector, using a paper clip or similar metal piece to touch the center pin of the connector to its outer metal sheath. The device should indicate “STOP” with its red LED and buzzer or beeper. If this does not happen there may be a problem with the instrument; contact us for more information.

3. Connect the electrode 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. [If it doesn’t you may have an electrode problem read in the next section below how to fix this.] Now add one drop of a concentrated sulfite solution (1-10% is fine) and verify that the STOP signal ends and the PROCEED light illuminates. If this happens, your electrode is probably OK as well.

4. Finally, you can check your SO2 reagents with the Ascorbic Acid Test.

Preconditioning of the electrode Note: as of October 2013, all SO2 electrodes are shipped pre-conditioned, so this procedure should not normally be needed. Sometimes when the SO2 electrode is first shipped it can be shipped “hot”. A hot electrode is one that is overly sensitive as indicated by high readings (and STOP conditions) when inserted into solutions that should be giving no signal, like pure water or water plus reactant and acid with a drop of 10% KMBS added. If your electrode shows this behavior, it generally can be fixed by pre-conditioning as follows:

1. First, turn the power on and press the MODE button until the instrument is in SO2 mode, then press ENTER. Attach the SO2 electrode to the SC-300 analyzer. Put 20 mL of distilled water (deionized water) in a beaker and add half a bulb squeeze of the acid solution, half a bulb squeeze of the reactant solution and let the SO2 electrode sit in this solution.

2. Then add one drop of 10% potassium metabisulfite solution (KMBS) to the beaker with the electrode in it. Swirl gently. The instrument LCD should now read 0.0 (in units of nanoamps) or close to it. If it is reading significantly higher than 20 on the screen, let the electrode sit in the solution for half an hour.

3. After half an hour rinse the electrode with distilled water. Put it in about 20 mL of distilled water. Again add 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. [If it doesn’t you may have an electrode problem]

4. Now add one drop of KMBS solution (1-10% is fine), swirl and verify that the STOP signal ends and the PROCEED light illuminates. If this is the case, your electrode has been conditioned. If the electrode is still “hot” and the PROCEED light does not illuminate, let it sit in 20 mL of distilled water with a half bulb full of the acid solution for a few hours. Now repeat the test from step 3. If it works, great! If not, call us and we will try to troubleshoot or replace your electrode. Our contact information is at the bottom of the page.

MLF Questions

How does the SC-50 MLF Analyzer compare to other methods?

Here is a study we did comparing the SC-50 to other methods. We get results that agree with standard analyses using very expensive equipment!

Vinmetrica’s instruments correlate very well with other methods

What are possible interferences in the MLF assay?

Very high alcohol levels may change the response of the system somewhat. The boiling step generally reduces levels far enough to limit this problem. For very high alcohol levels, you can dilute the wine in distilled water to bring the concentration below 10% ABV.
High free SO2 levels (>30ppm) may impact the Biopressure agent. Again, boiling will help this, but if needed you can dilute the wine sample as above.

What is the effect of temperature on the MLF assay?

Temperature can have a significant effect on the assay. The recommended temperature is standard room temperature, or about 70 °F (21°C). Temperatures within 3 degrees °F (or 1.5 °C) of this value should be fine. At lower temperatures, the rate of the Biopressure reaction slows down, and the pressure change also is lower, just like car tires lose pressure in cold temperatures. Therefore the assay is less sensitive at lower temperatures.

At higher temperatures, the opposite effect occurs: the reaction will go faster and generate higher values. In principle this is not bad per se – the assay becomes slightly more sensitive with the higher pressures generated. There is nothing wrong with using a higher temperature up to about 95°F (35°C), with two cautions: 1. the higher pressure resulting from higher temperatures may throw off the instrument’s 50 nA set point so it now will signal at a level below the 0.1 g/L level – therefore you will have to pay attention to concentration calculations; 2. most users’ environments aren’t set up to control higher temperatures that well, so increased variability may result. A warm water bath with controlled temperature can be used.

Services Page FAQs

Vinmetrica Labs Quality Guarantee

We offer quality laboratory testing for brewers and winemakers. We believe our clients should be guaranteed that their samples are handled with the utmost care and to the highest standards. Our laboratory services will be performed following the rigorous AOAC and TTB approved wine and beer analysis methods.

We try to minimize our changes in price for our laboratory services as much as possible. But the laboratory service prices can vary from time to time depending on the time of the year. All reports are strictly confidential and are meant for client’s use only. Our prices on our website reflect our up to date pricing.

Note: We are not responsible for wine samples that are improperly packaged, damaged or deteriorated during their shipment. Please contact us if you have any questions or concerns regarding shipping and handling. Our contact email: and our technical support and sales phone number is (760) 494-0597.

Receiving your Shipping Supplies

We send shipping supplies to you, free of charge, once you place your order.

Please make sure to send us your samples in a tightly sealed container per the “Wine and Beer Sample Shipping Preparation” instructions. Be sure to mark each sample, marking such as “Merlot A” or “Merlot B” are sufficient as long as you know which sample is which. The more detail the better.

*If you are sending an entire bottle, please let us know in the Customer Notes section during checkout.*

The Shipping Supplies includes everything below, with the number of tubes and size of the box based on how many tests you purchase:

• Cardboard box for returning the shipment
• 50mL or 15mL conical tubes (one for each analysis or two if the analysis requires a 100 mL sample)
• Vinmetrica Labs Conical tube labels
• Gel pack and Styrofoam container (for certain sample analyses, if sample requires being kept cold)

Once you have prepared your sample from the ‘Wine & Beer Sample Shipping Preparation’ instructions, make sure to attach a shipping label to the top of the cardboard box and ship to the address below. Please write on the box “For Laboratory Analysis Only”.

If you are near North County San Diego, feel free to stop by and drop off your sample Monday through Friday 9-3pm (please drop samples earlier in the day so they can be processed in a timely fashion). Our address is:


6084 Corte Del Cedro, Suite 105

Carlsbad, CA 92011

Beverage Sample Shipping Preparation

Shipping Preparations for Beverage Samples

Note: We recommend that you do not ship samples on Friday or Saturday as the samples could be compromised over the weekend due to deterioration of the sample. If shipping Thursday, make sure to ship via overnight, so the samples do not sit over the weekend.

1. Upon receiving your Vinmetrica Labs sample shipping kit, please place the gel pack in the freezer for 12 hours or until the gel pack is frozen solid.

2. Prepare the sample by filling up either the 15 mL or 50 mL conical tube then cap and seal tightly. Look on the Vinmetrica Labs Label for a Min. Volume necessary for that specific test.
Note: Fill the conical tube to a level above the beginning of the threads near the top of the tube to reduce headspace. (this is a volume either over 15mL or 50 mL depending on the size of the tube)

3. Fill out the Vinmetrica Labs label that is provided. Check the box for the test that you wish to be performed on your sample. Please include a phone number and an email address on one of the labels. Place the label on the tube so the label is not overlapping itself.
Note: One analysis per tube. Please only check one box per conical tube. Analyses require a certain volume which will be either the 15 mL, 50 mL or 100 mL Min. Volume category. For 100 mL analyses, please fill two 50 mL conical tubes as per the instructions above.

4. Repeat steps 2 and 3 for all sample analyses ordered.

5. Place the samples in the ziploc bag provided and seal shut. Place the ziploc bagged samples and the frozen gel pack into the styrofoam box.

6. Place the prepared styrofoam box into the cardboard box that is provided. Tape and seal the box closed. Print out a shipping label addressed to us (our address is below) and please write on the label, in a conveniently readable location, “For Laboratory Analysis Only”.

Note: The shipping supplies are provided free of charge. Expect arrival in 3-4 business days for handling and delivery of the supplies.

For Local Drop-off

If you are near North County San Diego, feel free to stop by and drop off your sample Monday through Friday 9-5pm. Our address is:


6084 Corte Del Cedro, Suite 105

Carlsbad, CA 92011

Shipping Questions

Canadian Customers Click Here

We ship to Canada via FedEx Ground. Vinmetrica does not pay for any duties, taxes or fees that are applicable upon entry but all freight charges are included. Click here to return to our North American Products page.


If you would prefer, you can purchase one of our products through our Canadian distributors. Click on the link above for a list of our distributors.


International Customers Click Here

If you are outside North America we must ship the acid reagent, 2M HCl (2N HCl) found in the SC-100A & SC-300 analyzers, the Pro Kit and the SC-100 & SC-300 SO2 Reagent kit in small 1 ounce bottles because of hazardous materials restrictions imposed by international shipping standards. This does not change the function or concentration of the acid solution and you still use 2 mL of the acid solution for each Free SO2 test.


If you are purchasing the large 450 mL volume bottles of the acid solution or the SC-100 & SC-300 SO2 Reagent set (these large replacement bottles which are sold separately from the units themselves), the acid solution will arrive in small 1 ounce bottles as well.


Similarly, we must ship the 100 mL of 1M (1N) NaOH solution in 1 ounce bottles (an optional item for doing Total SO2 analysis – not included with the analyzer or reagent kits) when ordered internationally because of these hazardous material restrictions.


Another alternative shipping method is to contact one of our distributors. If one of our international distributors is close to your location, we can get you in contact with them. Feel free to email,, or call us, if you have any questions regarding international shipping. We are available Monday – Saturday, 9am – 5pm PST: +1 (760) 494-0597


For more information on the Acid reagent check out the link below.

Additional Information

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

Replacement SO2 Electrode Purchasing Guide

pH: how to measure it, what it is, and how to use it

Managing pH and TA

Reagent Tests

The KHP test: Verifying TA Titrant Accuracy

The Ascorbic Acid test: Verifying SO2 Reagents Accuracy

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


SC-100A & the SC-100

  • Sensitivity: detects less than 2 ppm Free or Total SO2 in a 25 mL sample
  • 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
  • TA mode: Accuracy: +/- 0.2 g/L Tartaric acid.
  • Sensitivity: Detects down to 0.2 g/L Tartaric Acid


  • Combines the specs for the SC-100 and SC-200


  • Sensitivity: better than 0.04 g/L malic acid (3 mL sample)

14 thoughts on “Frequently Asked Questions

  1. I have ran the ABV test 3 times now and never get to the olive green color. ?? My samples after 24 or even 12 hours all have a blue tint before the test starts.???

    1. Hi, you are probably pipetting the wine sample incorrectly, adding too much. Read over the instructions in the manual for details on using the micropipettor to deliver 100 microliters precisely. Call my direct office line 760-494-0597 x 102 and we can walk through it.

  2. Hi, have had my SC-300 for several years, it’s great. Will you be offering a test for volatile acidity for the SC-300?

    1. Ken,
      We are glad to hear your SC-300 is working great for you. At this time we have no plans to offer an in-home VA test kit. The chemicals are quite noxious. We do offer VA testing through our Lab Services though.
      Thanks for the inquiry.

  3. Hi, couples questions here. Interested to use the S02 test on bottled cocktails and other also carbonated beverages. Will it be possible to take readings of bottled cocktails(spirit + citrus + sugar + water) and/or other carbonated beverages(sparkling wine/sparkling cocktails/etc.?)

    1. Jonathan,
      Thank you for contacting us. Yes, our SO2 analyzer can be used to test carbonated beverages. However, since you mentioned that there is citrus in these drinks you may have some issues depending on how much ascorbic acid is in your cocktail. If your ascorbic acid levels are significant then you can run in to some issues. If you suspect your ascorbic acid levels are low, we can provide you with a quick procedure to adjust for this. I think it may be best if you contact our Technical Support, either or 760-494-0597, and we can go over the specific requirements for your sample.
      Thank you

  4. I have the SC-100 instrument, which reaches the stop condition but then gives a reading that jumps around, even showing 0.00 in the process. I have yet to run the tests suggested – “For SO2 measurements with the SC-300 or the SC-100A, there are several quick tests you can do to make sure the instrument is not faulty.”
    What is likely the problem and how should I attempt to remedy it?
    Thanks, Jim Benn

    1. Jim,
      You may want to try cleaning your electrode by soaking it in your acid solution for about 30 minutes then gently scraping at those two platinum wires to remove any deposits. It is possible your electrode could be dirty. After cleaning, I suggest you try the “Reagent Test” for the SO2 function. The instructions for this test can be found on the Troubleshooting Guide. If you hover over the Support tab, the Troubleshooting Guide should be listed at the top. Give the reagent test a try and let us know how it goes. There are also some other tests there you can try that will help us determine what might be going wrong with your instrument, if anything.
      Let us know if you have any questions.

  5. Hi,
    I am a homebrewer looking into the SC-200 for testing pH and TA of my sour beers during the brewing process. I see that the SC-200 is labeled as a Wine Analyzer Kit, and refers to Tartaric Acid in subsequent text. Will it be able to test pH and TA of beer given the expected byproduct of lactic acid?

    1. yes you can do pH and TA on beer with the SC200. The pH is independent of the beverage or whatever solution it’s measuring. The TA is also; it’s just a matter of how you calculate the final answer. Wine TA is usually reported as tartaric acid but the titration actually measures acidity as equivalents per liter (eq/L). If you assume the acid is mostly tartaric (true for wine) then you use the conversion factor for tartaric acid (75), as we do in our kit. For a sour beer you would use the factor for lactic acid (90). So you could just convert as:
      g/L lactic = 90/75 * g/L tartaric.

  6. I have SC-300 that will not go to CAL mode. CAL flashes briefly and that’s it. The unit cycle through like it in testing mode and I don’t believe it’s calibrating

    1. Alonzo,
      I think it would be best if you contacted our Tech Support line, 760-494-0597. Its probably best if we walk through the diagnostics over the phone.

  7. Question on using transfer pipettes to obtain the 25mL sample for titration. I understand that the pipettes come in a sealed sterile package. Are these pipettes intended to be used only once – or can they be sterilized and reused? If so – what is the recommended process for cleaning and/or sterilization? I usually sanitize anything that comes into contact with the wine with Starsan. If I clean the transfer pipette with Starsan and then use it to obtain a wine sample for titration – will it impact the SO2 (or other) results? Thanks!

    1. Jeff,
      Great question! These pipettes are to be used multiple times. No need to purchase tons of them. We recommend the following procedure. When getting ready to take your 25mL sample for testing, rinse the pipette with DI water then use a 70% ethanol spray to clean the pipette. (remember not to use a sulfite solution here because that will throw off your sulfite readings!) Spray the pipette and wipe down with a clean paper towel. Take your sample and perform your SO2 test. Before you move on to the next sample, spray the pipette again with ethanol and wipe down. Some customers also rinse the inside with DI water again before spraying the ethanol but that is not necessary. I am unfamiliar with Starsan but if it is a common “food safe” sterilant (that does not contain sulfite) it should be okay.
      Let us know if you have any other questions.

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