Lately, I've been thinking about how much of a role apple variety and yeast actually play in the final flavour and aroma of cider.
From what I've been reading and observing in my own fermentations, I've started wondering whether some of the aromas we perceive during fermentation are largely transient. The juice can smell incredibly fruity, floral, or distinctly apple-like at the beginning, but much of that character seems to disappear as fermentation progresses. Meanwhile, the yeast produces its own aroma compounds, particularly esters that can resemble pear, banana, tropical fruit, and other fruits.
This raises an interesting question: how much of the final aroma actually comes from the apples themselves, and how much is created by the yeast?
If yeast primarily needs fermentable sugars, nitrogen, and other nutrients to produce alcohol and aroma compounds, how important is it to source and select particularly aromatic apple varieties? Could their main contribution to the finished cider be acidity, sugar content, tannins, and the overall chemical composition of the juice, rather than their original aroma?
Or is that an oversimplification? Surely, apple varieties contain different volatile compounds and aroma precursors that can survive fermentation or be transformed by yeast into entirely new aromatic compounds.
I'm also wondering whether traditional, slower fermentation is the key to preserving more of the original apple character. Most cider yeasts seem to have recommended fermentation temperatures somewhere around 16–20°C for good aromatic expression, but does a lower and slower fermentation actually preserve more varietal character, or does it simply change which compounds the yeast produces and retains?
I'd love to hear from people who have experimented with the same juice fermented with different yeasts, or the same yeast used on different apple varieties.
What makes the biggest difference in your experience ?
The apples, the yeast, or the fermentation conditions?
