SO2 level management - Best practice?

[nachov]

Hi everybody,

I'm new in winemaking; and I have a question concerning
SO2 level management:

Should I add more SO2 than needed just before racking;
so the SO2 would never lower below the needed level ?

Or should I compensate AFTER the free SO2 has fallen below the
needed level; and therefore raise the level to the needed level.

In a nutshell, my question is: what the best practice:

- compensate free SO2 level BEFORE loss
OR
- compensate free SO2 level AFTER loss

For instance, if my PH is 3.6 before racking,
and my current free SO2 level is 55 ( i.e at the needed level),
should I add 20 ppm SO2 BEFORE racking ?

I'm aiming to constantly maintain the SO2 level always at the needed free SO2 level; and never go down this level.

I don't know if this is good practice.
I would welcome any comments and suggestion.

By the way, I was wondering why SO2 level management is not
common practice in beer brewing. I know sanitation with SO2 (or other means) is paramount importance in beer brewing; but I've never heard of SO2 level management in beer brewing before.

What's so different in beer brewing?
Is is due to the fact that the "ingredients" in beer brewing are less exposed to the air. (the mash and wort are in contact with the air; but the relatively high temperature might protect them from bacteria infection).

Thank you for shedding me some light on this question

Cheers!

Nachov

 

[Runningwolf]

First off, welcome to the forum.
Second, get ready for a million different answers. The great thing about this forum is we'll tell you what we do and what works for us but then you'll have to decide which is the best procedure for yourself.

Some wineries will keep the S02 anywhere from 60-100 ppm right after fermentation until they are ready to do something with the wine ie. blend or bottle. Myself, I never add more them 60ppm regardless of the ph. After 60 ppm I feel you can begin to taste it.

I like to up the S02 5-10 ppm if I am getting ready to filter and bottle. You certainly do lose a good % during this period. If I am making a blend or just racking I take a measurement shortly after the wine enters the new tank. I figure out how much meta I need to add and put the addition in asap so it mixes in good with the rest of the wine entering the tank or carboy.

I always add kmeta to hot water and stir well until all is well dissolved. This also helps to ensure complete dismemberment. Hope this helps.

 

[Chiumanfu]

I'm still pretty new to SO2 management but my method seems to be working well and I'm sure it's the same process for most.

I measure and adjust free SO2 after the final racking before starting to bulk age. Every 3 months in bulk, I will take a sample and test it. And one last time after filtering right before it goes into the bottle.

I prefer to use the least amount of SO2 as possible so I don't think compensation before the loss is practical. A lot of times, if you rack very carefully, the free SO2 loss will be negligible.

 

[nachov]

Thanks for your contribution folks!

So, the way I understand free SO2 level now:

It's not necessary to have the free SO2 needed level ALL the time.
For instance, I would not need a 55ppm free SO2 level all the time ?

It's more like a protective buffer?
And it doesn't matter if a percentage of this protection has been consumed?

I guess the needed free SO2 level is worked out according to the worst scenario (like a very strong oxidation).

Is that right?


Cheers.

 

[robie]

Thanks for your contribution folks!

So, the way I understand free SO2 level now:

It's not necessary to have the free SO2 needed level ALL the time.
For instance, I would not need a 55ppm free SO2 level all the time ?

It's more like a protective buffer?
And it doesn't matter if a percentage of this protection has been consumed?

I guess the needed free SO2 level is worked out according to the worst scenario (like a very strong oxidation).

Is that right?


Cheers.

Every time you do something like rack the wine or place it in a barrel, the free SO2 level is going to drop some. The idea is to never let it drop too low. In order to accomplish that, you should test it every 6 to 8 weeks to bring it back up to where it is supposed to be (maybe 3 months in between if you are bulk aging with a solid bung). Those downward swings are not going to hurt anything if you test regularly and bring it back up.

 

[jswordy]

You asked for the BEST way, which is why I like Dan's (Runningwolf's) answer best. The BEST way is to measure ppm and add to a standard.

I might also say that if you overdo SO2 with some musts, you can bleach the color out. I like Dan's 60 ppm limit, too, because I can taste SO2 when it is too high.

SO2 offers protection against microbial infection and also against oxidation when wines are being transferred. It is also frequently used as a stabilizing agent. SO2 was first used by winemakers in the Middle ages (from sulfur), so it has been around in some form for a long time.

 

[nachov]

Fair enough!

I should bear in mind that overdoing SO2 would bleach the colour out (and probably some nice flavours as well).

Brilliant feedbacks.
Thank you.

 

[jswordy]

Fair enough!

I should bear in mind that overdoing SO2 would bleach the colour out (and probably some nice flavours as well).

Brilliant feedbacks.
Thank you.

I should add that in some musts and wines, adding any level of SO2 will temporarily bleach the color. Just so you don't freak out if it gets real light for a minute or two after you add, then returns to the former color.

Wineries run their SO2 levels sometimes as high or higher than 125 ppm, and I can taste that.

 

[vernsgal]

sorry if this is a high jack, I see measuring S02 mentioned a lot but what is the best way for measuring S02? or is there only 1 way?

 

[whackfol]

I'm aware of at least three principle methods of measuring FSO2: Ripper, Aeration and Oxidation and capillary electrophoresis. The last I only know from reading. The first two are widely used in winemaking. Variants of Ripper include the the basic test and packaged tests like titrettes, and more recently Hanna's autotitrator and Vinmetrica which read an endpoint with a probe. Generally the sample is acidified and then the result titrated. Until the Vinmetrica came out a few years ago, I used aeration and oxidation. It took a long time to perform, but the results were easy to figure as the endpoints were noticable. It too required acidification of the sample, but the SO2 is stripped from the acidified sample with air and the sulfuric acid is trapped in peroxide which is then titrated.

Back to the original thread, I'm not sure there is a BMP for SO2 additions. I have seen it performed differently in multiple large wineries and the feedback here indicates there are varied methods here. Personally, I test every time I move my wine, frequently when I first move to a barrel and then once it stabilizes every other month or so. It takes me about six weeks after I move to barrels to get it to stabilize. I do track my additions and have found that it has taken as much as three time the SO2 I required to stabilize my FSO2 during the first 6 weeks. In the end it's about protecting the wine.

 

[jswordy]

sorry if this is a high jack, I see measuring S02 mentioned a lot but what is the best way for measuring S02? or is there only 1 way?

This is about the cheapest way out that works for BOTH whites and reds.

http://www.midwestsupplies.com/free-so2-test-kit.html

I used this for illustration. Other vendors may have it cheaper.

 

[vernsgal]

Thanks guys. another thing to add to my growing lab lol