Conditioning technology is critical. The end-product manufacturer needs to research this aspect to ensure that the best is made of feijoa fruit flavours. i.e. that a juice or wine maker uses fruit that is conditioned to optimum ripeness for his/her product and that the fullest flavour possible is achieved. e.g. One processor conditions his fruit, for a quality juice product, considerably beyond the optimum standard for fresh fruit consumption. This may well be necessary for the best wine production.
There is no substitute for trial and error but a general might be - early fruit varieties (especially the thin skinned Apollo types) require less conditioning than later thicker skinned varieties such as Triumph and Gracie.
Even with processing it is better to pack by variety so fruit can be conditioned uniformly to an optimum end product stage.