adding Sulfite when bottling shortly after racking?

[studioso]

Hello!
I'm just did my second racking to a red wine I want to drink early, and added 1.6gm sulfites to a 6 gallon carboy. If I want to bottle it in a month or 2, would I add more sulfites? should I "pro-rate" 1.5gm or so for every 3 months?
and would it be different for a white wine?
PS I do not have equipment to measure sulfites but I do have a ph meter.
thank you!

 

[Jovimaple]

Welcome to WMT!

I always add potassium metabisulphite (Kmeta) at bottling time.

You should be okay with a normal dose, whether white or red wine - as I understand it, a normal dose is way less than the amount needed to give off flavors.

A normal dose of the Kmeta powder I buy is 1/4 tsp for 5 or 6 US gallons. I dose at every racking, every 3 months or so when bulk aging (even if I don't rack at that time), and at bottling. Kmeta protects against oxidation, and racking and bottling are the times when the most exposure to oxygen occur.

 

[Rice_Guy]

What you are doing is trying to preserve the redox potential of the wine. ,,, ie Oxidation causes off flavors and reduces the shelf life. As @Jovimaple said adding free SO2 at bottling makes sense, it is your last chance to build shelf in and the process of bottling may add 5mg of oxygen per liter or more. (The AWRI has done some surveys)

I have a Vinmetrica and some numbers. My “wild guess” for the actual when you don’t measure would be a tannic red or tannic apple or aronia tannin may have 10 to 20 ppm free SO2 . A low tannin country wine or white grape I expect 0 to a few ppm. On the other end If you get over 50 ppm free the better tasters will pick it out. ,,,
If others have trends please jump in.

 

[studioso]

I appreciate your input and help. my question was specifically how you would add sulfite at bottling even if you added at racking less than 3 months prior...

 

[winemaker81]

I appreciate your input and help. my question was specifically how you would add sulfite at bottling even if you added at racking less than 3 months prior...

I normally add K-meta at bottling as it's the last dose the wine will receive. If the wine is a short-term wine, used up within a year or so, it probably doesn't matter. OTOH, if you expect longer aging, you want that last dose of K-meta to address O2 exposure during bottling and things such as oxidation from sunlight and other contaminants.

The amount of K-meta we are talking about is way below the safe threshold for safe levels, so there is no harm in using it, unless someone who will drink the wine is allergic to sulfite.