# Cheaply testing so2



## Ajmassa (Jul 7, 2018)

So2 testing ain’t cheap. And I know lots of people avoid those titrets for red wine. It says so right on the packaging “recommended for white wines”. 
But they CAN be used for red wine. It’s just not as easy to see color change. They give accurate enough readings for what we need. And if not investing in a more expensive method-there’s no need to choose to not test at all instead of using titrets. 
This was checking the level after dosing at crush a couple months ago. 


A box of 10 tests is about $20. I also bought the “titrator” which makes it even easier to use. 


Each test is in a prefilled glass titret and a rubber tip for suction of sample. There is a white line and black line on the tip. 


The hose gets inserted into the tip and pushed down until it reaches the white line. The black mark is scored and the point where it needs to be broken. 
Insert the titret up through the titrator, hose end first and push all the in. When you bring that lever down it will crack the tip on that black line




Once cracked and the solution drops into the glass it turns black. This is the starting color. Finishing color is when the sample turns back to original color of the wine. 


Now it’s just a matter of pulling enough sample until finished. Just need to start going slow when it gets close. No different than a TA test by color change. There’s a little bead within the plastic hose tip you press on to pull up some wine


Now At the point when you start pulling in very small increments and checking color. This one is at 36ppm and color still darker. 


34ppm. Sample Still darker than the wine. 


31ppm still noticeable darker 


26ppm looks pretty close. Maybe a hair darker 


And 23ppm looks right on the money. 

Not exact- but it’s definitely close enough. Better to have an idea than to not know at all. Figured this might be helpful to anyone who has dismissed using these for red wine without actually trying.


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## NorCal (Jul 7, 2018)

Nicely presented, good job.


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## sour_grapes (Jul 7, 2018)

Thanks, that helps explain that process a lot!


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## Ajmassa (Jul 8, 2018)

Well I knew a lot people don’t really view these as a realistic so2 testing option for reds. But I’ve been using these without complaints for a few years now. I might test a wine 3x total. At crush- after MLF - and before bottling. And once in a blue I’ll test the level AFTER dosing- and always end up hitting the mark i was shooting for.
I use fermcalc http://web2.airmail.net/sgross/fermcalc/FermCalcJS.html to calculate the amount for whatever my target is. It takes everything into account. And i use the so2/ph chart to get my target.


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## Johnd (Jul 8, 2018)

Ajmassa5983 said:


> Well I knew a lot people don’t really view these as a realistic so2 testing option for reds. But I’ve been using these without complaints for a few years now. I might test a wine 3x total. At crush- after MLF - and before bottling. And once in a blue I’ll test the level AFTER dosing- and always end up hitting the mark i was shooting for.
> I use fermcalc http://web2.airmail.net/sgross/fermcalc/FermCalcJS.html to calculate the amount for whatever my target is. It takes everything into account. And i use the so2/ph chart to get my target. View attachment 49680



You do know that the chart you posted is the .8 molecular level chart.......the one we use for whites. See attached chart with both red and white depicted.


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## FTC Wines (Jul 8, 2018)

A J , great presentation, tried using that a few years ago & gave up. Your tutorial should help many have sucess! Finally looked around the winery room, realized what we had invested then said $300 for a Vinmetric 300 is probably a good investment. LOL, Roy


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## heyyou (Jul 8, 2018)

thank you for this presentation. I hqve been agonizing on how to do this and have be somewhat avordable


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## Ajmassa (Jul 8, 2018)

Johnd said:


> You do know that the chart you posted is the .8 molecular level chart.......the one we use for whites. See attached chart with both red and white depicted.
> 
> View attachment 49682



Thanks John. Good catch. I will edit that so it’s clear for readers. For whatever reason I couldn’t find the actual chart I typically use. Maybe because it was 2 am! That one was from morewine so2 manual. And .8 Molecular would be the max to use in my “graph of choice” here. Regardless- I’m always rounding down my targets and dosage- and rounding up current level anyway to keep so2 at a minimum. I need to print one of these out one day and put it on the wall in the wineroom. 
.


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## Ajmassa (Jul 8, 2018)

FTC Wines said:


> A J , great presentation, tried using that a few years ago & gave up. Your tutorial should help many have sucess! Finally looked around the winery room, realized what we had invested then said $300 for a Vinmetric 300 is probably a good investment. LOL, Roy



Thanks. The vinmetrica is on my list 100%. But im going for broke— the vinmetrica SC-300 with the “pro-kit”. All the bells and whistles. And the add-on YAN testing kit to boot. Rather expensive- and not exactly at the top of life’s priority list. 
Waiting for my ph meter to crap out on me before being forced to make a purchase. Until then- I’ll happily keep using these so2 titrets.


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## Mario Dinis (Dec 10, 2019)

Ajmassa said:


> So2 testing ain’t cheap. And I know lots of people avoid those titrets for red wine. It says so right on the packaging “recommended for white wines”.
> But they CAN be used for red wine. It’s just not as easy to see color change. They give accurate enough readings for what we need. And if not investing in a more expensive method-there’s no need to choose to not test at all instead of using titrets.
> This was checking the level after dosing at crush a couple months ago.
> View attachment 49665
> ...


A "bit" late, but thanks for sharing. Just learned something new.


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## Mario Dinis (Dec 10, 2019)

Ajmassa said:


> So2 testing ain’t cheap. And I know lots of people avoid those titrets for red wine. It says so right on the packaging “recommended for white wines”.
> But they CAN be used for red wine. It’s just not as easy to see color change. They give accurate enough readings for what we need. And if not investing in a more expensive method-there’s no need to choose to not test at all instead of using titrets.
> This was checking the level after dosing at crush a couple months ago.
> View attachment 49665
> ...


Just ordered this same kit to start experimenting.


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## rustbucket (Dec 10, 2019)

*Ajmassa,*
Thanks for the great write up on how to use titrets for red wine. I bought a box of titrets about 8 months ago but put them aside when I noticed that the box label said for while wines only. Now, as a result of your post, I will be using them. I'll be bottling six gallons of Malbec in January and will use the titrets to make sure that the batch has the proper sulfate level prior to bottling.


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## Mario Dinis (Dec 10, 2019)

rustbucket said:


> *Ajmassa,*
> Thanks for the great write up on how to use titrets for red wine. I bought a box of titrets about 8 months ago but put them aside when I noticed that the box label said for while wines only. Now, as a result of your post, I will be using them. I'll be bottling six gallons of Malbec in January and will use the titrets to make sure that the batch has the proper sulfate level prior to bottling.


Indeed it was a great post. I ordered one for myself.


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## jgmillr1 (Dec 11, 2019)

I built an AO unit pretty inexpensively. (This method is essentially the gold standard.)

It is simply
a stand that holds a couple big test tubes, an aquarium pump to flow air, reagents you can buy anywhere, two 2-hole stoppers, glass tubing I cut to length and some hosing to fit over it.


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## Ajmassa (Dec 11, 2019)

jgmillr1 said:


> It is simply...



I don’t think I’d use the term “simply”. Lol. 
That’s impressive. And I imagine every single thing needed to be modified. And not exactly items laying around the house either. Nice work


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## Mario Dinis (Apr 8, 2020)

How do you manage to draw a wine sample with this thing? I gave up on it. The scored tip of vial stays in the rube and I squeezed the bead and nothing comes in. What a fiasco.


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## bluecrab (Nov 11, 2020)

I have an AO setup to test free SO2, but it is a hassle to use, so I don't test often. Today, I tested to see if Titrets are accurate enough for my purposes. I want to keep my SO2 between 0.5 mg/l molecular (minimum to protect red wine) and 2 mg/l molecular (sensory threshold of SO2). I tested my wine that has no added SO2, so I have a good idea how much SO2 should be present. I followed the suggestions below to simplify detecting color change and to calculate my results.

Preparing wine sample:

"Another trick to help improve color change detection in red wines is to dilute the wine sample by 50 percent, for example. The test result should be compensated accordingly to obtain the actual free SO2 reading. For example, if the wine is diluted to 50 percent and a free SO2 reading of 20 mg/L is obtained, the actual concentration is 40 mg/L." [Solving the Sulfite Puzzle - WineMakerMag.com]

Error correction:

"This data suggests that the difference between values obtained from AO and Ripper methods varies from zero to 20 or 30 mg/l, depending on the wine style. For less phenolic wines, the difference may be typically zero to 10 mg/l, whilst for more heavily extracted wines the difference may be 15-20 mg/l. These factors may be used when correcting values obtained with the Ripper method." [Improved Winemaking: Sulphur Dioxide]

I took a sample of this year's Cabernet Sauvignon from the middle of the tank, as wine near the surface may have depleted SO2 levels. I diluted the control wine sample with 50% distilled water. The result was 16 ppm SO2. To correct for the dilution, this is 32ppm SO2 in the control that had no SO2 added by me. My error is roughly in line with the research noted above. This was my first time using Titrets, so I may do this again to see if I get the same result. I'm curious whether the turbidity of my young wine increased the error. For now, though, it's good enough for me.

After that, I tested my Super Tuscan from last year that is still maturing in a Flextank. I added 50ppm SO2 at crush and another 150ppm SO2 during the year. I was happy to see that it still has at least 14ppm free SO2, today. Without testing, I would have added another 50ppm. I'll probably only add 25ppm, now.


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## bluecrab (Nov 12, 2020)

Here's some additional safety information for anyone using Titrets.

When I pushed the valve assembly (the flexible tube) on the ampoule (the glass tube), a drop of clear liquid came out of the valve assembly and fell on my countertop. I had not yet snapped the tip of the ampoule. I asked the manufacturer what the liquid was and whether it is important to the test results.

Here's their reply.

"The liquid in the valve assembly is 85% phosphoric acid. You should take caution of avoiding contact with skin in wiping up any additional spills if that is to happen again.

"A drop of phosphoric acid can occasionally fall from the valve assembly tip when applying it to the ampoule. As long as there is even a small amount of acid in the valve assembly, the test will work properly."


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