How Much So2 To Add To Wine

Protecting your wine with gratis SO2

Keeping the required amount of gratis SO2 in your vino is one of the important post-fermentation care steps yous'll need to stay on top of. While some people decide not to add SO2 (which is a personal preference, though we at Musto Wine Grape definitely recommend keeping the proper amount of gratis SO2 in your wine at all times), others choose to keep their wine protected by using it diligently.

Why we add it

To keep the wine protected. KMS serves as an antimicrobial and antioxidant and as such is a very important part in keeping your wine out of harm's fashion. Without information technology, your wine tin become bad very quickly.

How to exam free SO2

Aeration oxidation method , manual ripper method , Vinmetrica , Hanna titrator , titrets

Setup for "aerative oxidation" method of checking free SO2. Though time intensive, it yields exact and accurate reuslts.

When to add it

During crush (to kill off whatever unwanted native yeast)
When fermentation has completed ( exist certain that MLF has completed as well, if that's the goal)
During aging. Case: Each month many winemakers will test SO2, make any SO2 adds if needed, and so elevation it off.

Investing in Vinmetrica SO2 vino analyzer makes testing easy

How to add it

You'll need to get potassium metabisulfite, if you don't already take it. You may prefer to apply campden tablets, which is fine too. Brand certain it says potassium metabisulfite rather than sodium metabisulfite. The easiest way to figure out how much free SO2 you'll need to add is to know your pH, first of all. Then you'll need to decide if you're using .8 or .5/6 molecular SO2. .viii is ordinarily used for white wines, whereas .5 is used for red wines. Mensurate your free SO2 if you have a manner of doing then. And so utilize the graph beneath to figure out what the target costless SO2 is. From there yous will likely choose an like shooting fish in a barrel-to-use online resources such equally wineadds.com to find out exactly how many grams of potassium metabisulfite should be added. Mix it with a small amount of water to ensure information technology tin can become completely incorporated into the wine.

*Call up: but knowing your target costless SO2 in ppm does NOT tell yous how many grams yous will be adding. You demand to figure that out as a 2d stride, with an online SO2 reckoner*

Graph indicating required free SO2

Now that you take a solid understanding of why, how, and when you lot add meta, you may want to delve into some deeper questions, such every bit…

Why do I demand to continue calculation meta? If I add a certain amount shouldn't information technology stay at that number?

This is a slap-up question. There are a lot of variables that become into answering this in every bit cohesive a way possible, and this could really exist a topic in and of itself. Let's keep it simple hither: there are two measurements of SO2 in wine: gratuitous and bound. The complimentary SO2 is what is actively protecting the wine, whereas spring SO2 is what has already tacked on to other compounds within the wine and as such is no longer able to actively protect information technology in the same way. Both are of import numbers, but if a winemaker is merely checking one, information technology'due south going to be free. Over time gratuitous SO2 can become bound to various acids, solids, sugars, bacteria, yeasts, etc., that are nowadays in the wine, which is why this number will non necessarily stay abiding, especially immediately.

Why does pH affect how much SO2 I need to add?

A rule of thumb to remember is that higher pH = higher free SO2 requirement. Lower pH = lower free SO2 requirement. The chart below demonstrates the amount of gratuitous SO2 required base of operations don the pH of the vino. This is just one of the many reasons that checking and knowing your wine's pH is critical.

Practise I need to measure total SO2 also?

Knowing this number is important, but non as crucial as knowing your free SO2. It's also a little less attainable of a examination to run, which is why near home winemakers don't choose to pursue knowing the full SO2 of their wines. It is possible to overadd SO2 and accept the total SO2 exist higher than desirable which can exist problematic, and so be sure to proceed a running log and closely track how much you lot take added from the beginning of the wine'southward life onward.