Originally Posted by ACbrewer
You have to sanatize the fruit somehow - boiling is one way of doing it. Also it has to go in before bottling (primary, late primary, secondary, etc) unless you pasturize after bottling, like right after. They yeast will eat the fruit sugar and cause bottle bombs.
You ask -KingofSweden- if you need to sanitize juice from frozen fruit or fruit concentrate. If you are using commercial fruit concentrate - and you are in the USA - I am sure that on the package there will be some statement that describes how the juice was preserved - The word "sorbate" refers to a chemical sanitizer which results in the juice having a long shelf life and will not be successfully fermented. The term pasteurized will suggest a different method of preservation. The addition of sorbate prevents yeast from reproducing.
The package might also say that the contents were UV or heat pasteurized.
My point: in the USA it is rather difficult to sell processed foods that have not undergone some method of eliminating and controlling bacteria and fungal growth. Personally, I am quite happy to rely on FDA required and reviewed processes. If juice was pasteurized by the packer. It is pasteurized when I bought it and remains pasteurized until I open it. And if when I open it I pitch the yeast then I trust that for all intents and purposes, the first significant colony of organisms contaminating the juice is the yeast I just pitched. In other words, there is nothing to be anxious about.
If, however, you process the juice yourself (pressing or squeezing juice from fresh fruit) then you do need to add K-meta (Campden tablets) to kill bacteria and fungi. After all , the fruit may be covered in bacteria and wild yeast. You wait 24 hours before pitching the yeast after crushing and adding 1 tablet for each gallon of liquid. The benefit of adding K-meta (potassium meta-bisulfite) is that if you heat juice to pasteurize it then you will likely evaporate off the more volatile aromatics and flavor molecules. Not a problem, IMO, if you are looking for a wine close to rocket fuel in terms of its alcohol content or you are making the wine (or cider) simply for the buzz. If , on the other hand, you are trying to bring out all the nuances of flavors and smells the fruit has to offer then at appropriately low doses of K-meta you are unable to detect the presence of the free SO2 (that is the bactericide in K-meta) and it does not mask the flavors or the nose of the fruit. So, if you buy commercially prepared juices then they are almost certainly sanitized when packaged. If you press or squeeze the juice from the fruit then you need to make sure that all unwanted bacteria are history.