vinmetrica SC-300 User manual

SC-300 manual 1 Version 2.1
Vinmetrica SC-300 Kit™
User Manual
The Vinmetrica SC-300*is a simple and robust device that provides high accuracy in determination of
sulfite (SO2), pH and titratable acidity (TA) levels in wine. These are essential parameters to control in
the effort to make high quality wines.
Table of Contents:
Materials Provided in the Kit............................................................................................................... 2
Things you will need............................................................................................................................ 2
Why Test for SO2, pH and TA?............................................................................................................ 3
Theory of Operation............................................................................................................................. 4
Setup.................................................................................................................................................... 5
Setting up the SC-300 for the first time................................................................................... 5
Instrument Operation....................................................................................................................... 7
Procedures.......................................................................................................................................... 9
Measuring Free Sulfite (SO2) by Titration.............................................................................. 9
Measuring Total Sulfite (SO2) by Titration.............................................................................. 12
Calibration of pH .................................................................................................................... 12
Measuring pH........................................................................................................................... 13
Measuring Titratable Acidity (TA) by Titration....................................................................... 14
Finishing up............................................................................................................................. 16
Warranties, Liabilities & Hazards.................................................................................................... 17
Appendix A - Test Mode..................................................................................................................... 18
Appendix B - Sulfite & TA Adjustments........................................................................................... 20
Appendix C1 - Troubleshooting: pH and TA Issues........................................................................ 21
Appendix C2 - Troubleshooting: SO2Issues.................................................................................... 23
*US Patent pending

SC-300 manual 2 Version 2.1
Materials provided in the kit:
1. Vinmetrica SC-300 SO2/pH controller unit
(Part number SC-300-1)
2. SO2Electrode (Part number SC-100-3), blue
polycarbonate housing
3. pH Electrode (Part number SC-200-3), red
polycarbonate housing
4. SO2Reagent set (Part number SC-100-2):
SO2Titrant solution (0.0156N)
Acid Reagent
Reactant solution
5. pH/TA reagent set (Part number SC-200-8):
pH 4.01 calibration solution
pH 7.00 calibration solution
TA titrant (0.13 N NaOH)
6. Two 5 mL syringes
7. Two 3 mL polyethylene transfer pipettes
8. One 25 mL serological pipette
9. One 5mL serological pipette
10. 100 mL polypropylene beaker
Things you will need:
1. Two standard AA batteries (alkaline type).
2. Distilled water, which usually can be found at your local grocery store. It’s handy to have a wash
bottle for rinsing. Rinse bottle available from Vinmetrica (Part number SC-100-17)
3. (Optional) Deluxe Lab Accessory Kit which includes: magnetic stirrer, burette (10mL or 25mL),
lab support stand and electrode holder. Available from Vinmetrica (Part Number SC-300-9,
https://vinmetrica.com/product/the-deluxe-lab-accessory-kit/ )
4. (Optional) Sodium Hydroxide solution, 1N concentration (if you want to do total SO2). Available
from Vinmetrica (Part number SC-100-7)
Figure 1. The SC-300 instrument with the SO2
and pH/TA electrodes.

SC-300 manual 3 Version 2.1
Why Test for SO2, pH and TA?
Testing for sulfite (SO2) is crucially important for making sure your wine does not spoil by
oxidation or from microbial growth. Having the proper SO2level in your wine gives you this protection.
By monitoring your SO2levels, you can make adjustments when needed, especially before starting
primary fermentation, after malolactic fermentation has completed, after racking or when ready to
bottle. To correctly adjust sulfite, you need values for your current "Free SO2" level and your wine's pH,
both of which can be measured with the Vinmetrica SC-300 analyzer.
The key parameter in protecting your wine is "Molecular SO2" which for most wines should be
at 0.8 ppm (mg/L) following primary fermentation. This in turn depends on the "Free SO2" (it can also
be referred to as "unbound" SO2) and the pH. Overall, you can reach your target Molecular SO2by
measuring and adjusting your free SO2levels and considering your wine's particular pH. See Table 1.
Table 1. Free SO2concentrations necessary to attain 0.8 mg/L Molecular SO2at a designated pH.
Free SO2(ppm)
13
16
21
26
32
40
50
63
79
99
125
pH
3.0
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4.0
We recommend using a sulfite calculator for determining how much sulfite to add to your wines
after taking a sulfite measurement with the SC-300 Analyzer Kit. Winemaker Magazine's Sulfite
Calculator at http://winemakermag.com/guide/sulfite can walk you through the process. See Appendix
B for more information on how to adjust your wine for sulfite.
Monitoring your wine's pH is especially important for the first few months of the wine making
process. Proper pH and Titratable Acidity (TA) levels influence mouth feel and provide wine stability.
During malolactic fermentation, the pH can increase somewhat and should be monitored. Typically,
wine pH and TA are inversely related; when pH goes up, TA goes down and vice versa. Adjustments
may be made to your wine to prevent wine instability. See Appendix B for more information on
adjustments.

SC-300 manual 4 Version 2.1
Theory of operation:
Sulfite (SO2): The SC-300, with the SO2 electrode and reagents provided, can be used to determine
sulfite (or SO2)levels in wine, musts, and other samples. It relies on the Ripper titration based on the
quantitative reaction of the SO2with iodine (generated during the titration) which oxidizes the SO2in
the sample under acid conditions.
IO3
-+ 5I-+ 6H+3I2+ 3H2O generation of iodine from iodate
SO2+ I2+ H2O 2I-+ SO3 + 2H+reaction of SO2and iodine
When all the SO2is titrated at the endpoint, excess iodine appears in solution. This is detected as
current with the SO2electrode and signaled by audible and visual indicators. The endpoint is much
more sensitive than the starch color change commonly employed for Ripper titration, and it is sharp
and clear, even when titrating red wines and musts. From the known concentration of the titrant and its
volume required to reach the endpoint, the free SO2is simply calculated.
pH and TA: The SC-300 kit also provides a pH electrode and reagents for calibration and
determination of pH and titratable acidity (TA) values in wines and other samples. The pH value is
simply determined by placing the calibrated electrode into a sample and reading the value. TA is
determined by titrating a 5 mL sample of wine to an endpoint pH of 8.2 with the TA titrant (0.13N
NaOH) from the syringe in the kit. From the known concentration of the TA titrant and its volume
required to reach the endpoint, the TA is simply calculated (results are in units of g/L tartaric acid).

SC-300 manual 5 Version 2.1
Setup:
Setting up the SC-300 for the first time:
1. The SC-300 (See Figure 1) runs on two standard AA batteries (alkaline cells recommended). To
insert the batteries, open the battery housing on the bottom of the back of the unit by removing
the two screws and gently prying off the lid. Install the batteries with the negative '-' end
contacting the coiled springs and the positive '+' end contacting the raised metal inserts then
close the housing. If desired, you can prop the unit up using its folding stand.
2. Low Battery Detection: When the battery level is getting low, the instrument will show a low
battery icon on the upper left side of the display but continues to operate without impairment to
any function. Replace the batteries as soon as practicable. When the battery level drops too far,
the instrument does not operate. It rapidly flashes the low battery icon for 3.0 seconds, beeps
and shuts itself off.
3. Auto Shut-off: The SC-300 shuts off after 30 minutes. If this happens unexpectedly, just press
the POWER button to resume from where you were.
4. Electrodes: When directed to do so, attach the desired electrode (pH or SO2, Figures 2 & 3) via
the BNC connector protruding from the top. Be sure to secure the electrode plug to the BNC
connector to insure proper function.
5. SO2electrode: Remove any protective cover from the electrode tip (some electrodes are
shipped without one). This cover is for shipping protection and need not be used routinely.
Put the electrode on its side, or hang it from an electrode stand if you have one. The SO2
electrode (blue) is sturdy with its plastic housing, but do take care not to let things touch or
strike the platinum wires; they are somewhat fragile and will break if bent and straightened
repeatedly. Electrode care: When done, always rinse with DI water and let air dry. There is no
need to store the SO2electrode in any kind of solution.
Figure 2. Attach the Electrode
you are using to the BNC
connector on the SC-300
Figure 3. Be sure the Electrode
attachment is screwed into place
on the BNC connector.

SC-300 manual 6 Version 2.1
6. pH electrode: Attach the pH electrode via the BNC connector on the top of the SC-300 (see
Figures 2 & 3). A note about the pH electrode: The pH electrode is fragile and should always
be handled carefully. Remove the liquid storage bottle by unscrewing the cap first, then gently
pulling the bottle, followed by the cap, off the electrode. Rinse the electrode in a little distilled
water before each use. Electrode care: Do not touch the glass bulb, nor attempt to wipe it with
anything. When necessary, you may gently blot excess liquid away from the electrode surface,
but avoid directly touching it. The pH electrode should always be kept in the liquid storage
bottle with its pH storage solution (available from Vinmetrica) when not in use. Rinse the
electrode with DI water and gently blot or shake off excess water. Push the electrode through
the hole in the cap about an inch, then gently screw the bottle onto the cap so that the electrode
is in contact with the solution in the bottle.

SC-300 manual 7 Version 2.1
Instrument Operation:
1. Disconnect any electrodes. Turn on the instrument by pressing the POWER button briefly (Note:
depressing the POWER button longer than two seconds at start-up will cause the instrument to
enter Test Mode; see Appendix A). The instrument will go through a power-up sequence. After
a few seconds the instrument will start in whatever mode was last selected. The mode is
indicated by the yellow LED panel on the left. Select the desired mode by pressing the MODE
button.
2. SO2mode: This is for titration in determining ppm of SO2 (see below under ‘Procedures’). The
SO2 electrode must be used, but do not attach the electrode yet. [Warning: The pH electrode
can be damaged by connecting it to the instrument in SO2 mode. As a safety precaution, you
must press the ENTER button after selecting SO2mode to confirm that the SO2electrode is
attached before the mode will be enabled. However, scrolling through the MODE selections
(such that you pass by the SO2selection) with a pH electrode attached is safe, as long as you do
not press ENTER to confirm the SO2mode.] After pressing ENTER, you should see the
display show a value less than 50 (usually 0.0) and the green "PROCEED" LED should be
on. Now you can attach the SO2 electrode.
3. [Optional] Precondition the SO2Electrode:*All SO2electrodes are pre-conditioned at
Vinmetrica before shipment. Therefore normally you should skip this step. If you think your
electrode is not functioning properly you may try pre-conditioning the electrode. See Appendix
C2 for more information on preconditioning the SO2 electrode.
4. pH mode: In this mode, the meter measures the pH. The pH electrode must be attached. If the
instrument has not yet been calibrated, the message “doCal” scrolls across the screen, and you
will need to do a calibration (see Calibration of pH below). We recommend re-calibrating the
instrument for pH once each day of use, or whenever the Reference solutions do not give the
expected pH in pH mode. Warning: Be careful not to press ENTER when the pH electrode is
attached while the instrument is in SO2mode, as this can potentially damage the pH electrode.
If this does happen, and the pH electrode does not respond correctly, place it into the pH 4
Reference solution for an hour and it should return to normal function.
5. TA mode: This is for titration in determining titratable acidity (TA). As in the pH mode, the pH
is displayed and the pH electrode must be attached. The green (“PROCEED”) LED is lit if the
pH is below 8.2, while the red "STOP" LED is lit if the pH is 8.2 or greater. (see below under
Measuring TA by Titration )
6. CAL mode: This is for calibrating the pH electrode, which must be attached. The display
initially shows CAL for a few seconds as it prepares to read pH and lets readings settle.
Thereafter, the display shows the measured pH level with two decimal places.

SC-300 manual 8 Version 2.1
7. Calibration works with one of the following reference calibration sets:
pH 4.01 and 7.00 or “4/7”
pH 7.00 and 10.00 or “7/10”
pH 3.00 and 7.00 or “3/7”
Vinmetrica recommends use of the pH 4/7 Reference Solution set provided with the kit.
8. The magnetic stirrer has two modes. Pressing the "light bulb" button on the magnetic stirrer
activates a light underneath the sample and the stirrer. The power button activates just the stirrer.
After pressing either button, the stirrer remains active for 60 seconds, a feature to conserve its
batteries. If during the titration it turns off, simply press the button again for it to continue. We
recommend using the light mode because it helps us indicate when the stirrer stops. Plus when
doing TA titrations watching the wine turn from deep red to dark green is cool!
Note: When using the magnetic stirrer, be sure that the electrode does not touch the
spinning stir bar as this can potentially damage the glass bulb of the pH electrode or the
platinum wires of the SO2electrode. If you are using the Vinmetrica Electrode Holder, adjust
the electrode’s height so that its probe end is above the level of the stir bar.

SC-300 manual 9 Version 2.1
Procedures
Measuring Free SO2by Titration:
1. With the electrode disconnected, turn on the instrument and select SO2mode with the MODE
button. Press ENTER to confirm selection of SO2mode (Figure 4). The display should show a
value less than 20, usually 0.0. Now attach the SO2 electrode.
2. Fill the syringe by drawing up the SO2Titrant (the bottle with the blue label) (Figure 5). Expel
bubbles and set the plunger on the syringe to a readable point, preferably the 5.0 mL point.
Make sure the outside of the syringe is dry, to minimize any inaccuracies. [Note: the 5.0 mL
setting allows determination of up to 100 ppm SO2 in a standard 25 mL wine sample.] If using
a burette, use the syringe to dispense the SO2titrant into the top of the burette. Make sure the
burette stopcock is in the closed position (i.e., the handle is horizontal). When filling the burette
make sure the SO2titrant has completely filled the bottom of the burette including the tip.
Sometimes bubbles can be trapped in the tip of the burette but can usually be dislodged by
opening and closing the stopcock while the burette is above a waste container. If you spill any
titrant on the outside of the burette, be sure to clean it up with a paper towel or dry rag. If the
spilled titrant is not cleaned from the outside of the burette you may introduce these spilled
titrant droplets into the wine sample leading to an inaccurate reading. Be sure to record your
starting burette or syringe volume; refer to 'Burette Reading' section under the Setup section for
how to measure accurately.
Figure 4. Once in SO2
MODE the instrument
should read
'Press Enter' Press
ENTER to activate SO2
MODE.
Figure 5. Withdraw the
titrant from its bottle
using a clean 5 mL
syringe. If you are using
the glass burette, use the
syringe to fill it.
Figure 7. The transfer
pipette. One full squeeze
of the transfer pipette in
either the Acid solution
or Reactant should be
approximately 2 mL.
Figure 6. Dispense 25
mL of your wine into the
titration beaker using the
25 mL sampling pipette.
Make sure this is clean
before putting the pipette
into your wine container!

SC-300 manual 10 Version 2.1
3. Place 25 mL of wine or must in the titration vessel. We recommend using the 25 mL sampling
pipette provided in the kit: draw the sample up to the 0 mL mark, and then dispense the sample
into your titration vessel by letting the tip of the pipette touch the side of the vessel while the
sample drains (See Figure 6). NEVER pipette any reagents by mouth! Also make sure the
pipette you are using is completely clean before submerging into your wine sample.
4. Using the transfer pipettes (see Figure 7), add about 2 mL Acid Reagent and 2 mL Reactant
solution to the titration beaker (the two transfer pipettes should come with red and yellow labels,
with red for the Acid Reagent and yellow for the Reactant). It is not necessary to be extremely
accurate in this step; with these pipettes, 2 mL is roughly the amount that fills the pipette up to
the 2 mL mark after a single thorough squeeze of the bulb. To preserve the shelf life of these
reagents take care not to cross contaminate the transfer pipettes. If they do get contaminated
rinse them off with distilled water and let air dry. Caution: the Acid reagent is corrosive and
can cause damage to clothing, skin and eyes. The Reactant solution should not be ingested.
ALWAYS use safety glasses! We recommend the use of laboratory latex or nitrile gloves
during this procedure. If any solutions contact skin or eyes, flush with plenty of water.
5. If you are using a magnetic stirrer, turn it on to stir at a moderate rate. The Magnetic Stirrer
provided with the SC-300 Pro Kit operates at a suitable preset speed. Make sure your electrode
is not struck by the spinning stir bar. To prevent this, we recommend using the Vinmetrica
Electrode Holder to stabilize your electrode.
6. Rinse the electrode briefly with distilled water. Insert the electrode into the titration beaker so
that the tip is completely submerged to just above the circulation gaps (cutouts at the tip of the
electrode) but above the level of the stir bar (approximately half an inch from the bottom of the
titration beaker). If you are using the Vinmetrica Electrode Holder adjust it to a similar level.
7. If you are stirring manually, begin now; use a constant moderate swirling motion. If the
electrode is not held in a stand, hold it against the side of the vessel with one finger and grasp
the vessel with the remaining fingers so that the two move together. (See Figure 8).
8. Verify that the current is less than 50 and the green (“PROCEED”) LED is lit (See Figure 10).
If the current is greater than this, and/or the red (“STOP”) LED is lit and the buzzer sounds,
your sample has less than 2 ppm SO2and there is no need to proceed. (Verify that your SO2has
been preconditioned; see step 3 in the Instrument Operation section of the manual).
9. Titrate the sample by adding the SO2Titrant drop wise from the syringe (See Figure 8) or from
the burette (See Figure 9), being sure to note the starting volume mark on the syringe or burette.
Try to accomplish the titration as rapidly as possible (in 3 minutes or less), but be careful near
the endpoint so as not to overrun it –here, dispense one or two drops at a time. Be sure to
maintain stirring or swirling throughout the entire procedure. If the magnetic stirrer turns off,
turn it back on.