Hiya, homebrew pauly. If you added any powders or granules to a wine that is saturated with carbon dioxide (and remember that half the weight of the fermentable sugars are transformed into CO2 and half are transformed into alcohol - so that is a lot of carbon dioxide) then those particles will "nucleate" the CO2 and allow the gas to collect in large bubbles and that collected gas has a large amount of energy - enough to force up sediment and tiny bits of fruit and other compounds. In fact , if the carbon dioxide is under pressure when you add particles you can create a volcano as the gas will force up columns of wine through the mouth of a carboy - with enough energy (often) to paint your ceiling... Okay. That said, before adding any powders to wine a few days after pitching the yeast, the best approach is always to dissolve the granules or powders in water. It's the surface of the granules that cause the problem.
