Sodium Metabisulphite (campden tablets) are used to stop the wine spoiling you need fermentation stopper but as it says below it doesn't stop an active fermentation, you are best leaving it until its stopped fermenting fully then rack onto a crushed campden tablet and then add stabiliser.
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Campden Tablets - Sodium Metabisulphite
Sodium Metabisulfite, (often referred to as SO2, sulfites meta, or meta-bi) has several uses in winemaking. It is used at the crush, to help control the spoilage bacteria and indigenous yeast that may already be present on the fruit or the equipment. The amount used is enough to stop most of the unwanted organisms but not enough to hinder a cultured yeast, which has a higher tolerance to sulfites. This effectively “wipes the slate clean” for the cultured yeast to step in and rapidly colonize the must.
Sulfites also help to inhibit the enzymatic browning of musts and finished wines. During storage and in the bottle, sulfites at the proper levels will protect a wine by continuing to inhibit spoilage organisms, as well as by scavenging oxygen.
Campden tablets are Sodium Metabisulfite in an easier to measure format. Adds 75 ppm of sulfites at the rate of one tablet per gallon. These must be fully ground-up prior to use. Potassium Meta-bi in powder form, AD495 or AD500, is much easier to use if you have a scale and does not add sodium to your wine.
It is possible the sodium could contribute a very small salty flavor. Especially when making white wine it is preferable to add potassium over sodium since added potassium can later help with cold stabilization.
For more information refer to our MoreManuals! on Red or White Winemaking or one of the winemaking books that we offer for a complete explanation on how to properly manage sulfites.
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Fermentation Stopper ( Wine Stabiliser ) 30grm
Description
Also known as Potassium Sorbate. Added to a wine to stop the fermentation and prevent a re-fermentation after bottling
Potassium Sorbate is another home wine making ingredient that many winemakers consider when trying to stop a wine from fermenting any further. There is a lot of misunderstanding surrounding this product.
It is typically called for by
home wine making books when sweetening a wine. This is a situation where the fermentation has already completed and is ready for bottling. You simply add the Potassium Sorbate along with the sugar that is added for sweetening.
The Potassium Sorbate stops the wine yeast from fermenting the newly added sugar. So, many winemakers assume Potassium Sorbate can stop an active fermentation as well. But, nothing could be further from the truth.
Potassium Sorbate does not kill the yeast at all, but rather it makes the wine yeast sterile. In other words, it impairs the wine yeast's ability to reproduce itself. But, it does not hinder the wine yeast's ability to ferment sugar into alcohol.
Potassium Sorbate puts a coating on the cell wall of each individual wine yeast in such a way that budding or multiplying is next to impossible.
The idea here is that if you happen to have few cells of live wine yeast remaining in your finished wine, they will be rendered harmless if they are unable to regenerate themselves to great enough numbers to invigorate a fermentation of any kind. This is true even if more sugar is added to the finished wine.
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