PMS addition
thanks for all your answers - I will decide if I want to mix it or go from the big demi-john to a smaller one and mix it in the smaller one and then bottle it. Thanks again
For that ammount of wine the best thing you can do is mis the PMS (postassium metabisulfite) in a glass of warm water, and mix it. It will mix perfectly. Then add the mix to the wine and stirr a little. Then bottle the wine.
Warm water wont make a difference in the ammount of PMS that you will be adding (thinking of losses because of gases)
Half a glass of water wont make a difference in such ammount of wine
And stir a little wont make a difference too with the oxigen. Specially if it is red wine that supports better the oxidation.
In winery scale, the thing i like to do with the addition of PMS is after ML fermentation, is to rise the free PMS to 35ppm. to do this i doit in a whole week with 3 additions. PMS after ML combines a lot faster, so if you add a bunch at the begining my experience says that you get a lot combined and it takes more PMS to reach the 35ppm of free sulfur.
cheers
jose