Fermentation, from the Orchard to the Barn
In this series, we look at ‘How We Make Cider and Perry’ – alcoholic drinks fermented from apples and pears. In part one we looked at the Apple, the Harvest and the Pressing – you can catch up here
This time we look at Fermentation.
So, you have your apple or pear juice, how does this turn to cider/perry? Fermentation is the process whereby sugar is converted to alcohol by yeasts.
Primary fermentation – starting with the froth
There are two stages to this, a primary fermentation followed by a slower ‘malolactic’ secondary fermentation.
Primary fermentation starts quickly, but the time taken for yeasts to use up all the sugars in the apple juice is dependent on the type of yeast used, of which more later, and on the temperature at which fermentation takes place.
Fermentation starts with an aggressive froth, as this slows airlocks will keep out exposure to bacteria in the air..
Warmer ambient temperatures will help yeasts work quicker but many cider makers will leave the cider over winter for a longer slower fermentation. In perry, not all the sugars are available to the yeast. Pears contain sorbitol which is a non-fermentable sugar. It is this that gives perry its natural sweetness.
Slowly maturing – malolactic fermentation
During the secondary fermentation the sharper malic acid is converted into softer lactic acid. This is carried out by lactic acid bacteria which are present in the apple juice and in the area in which the fermentation is carried out and normally happens in the late spring or early summer.
This maturation process takes anywhere from a few weeks to a couple of years and is essential for a good flavour balance. It is during this period that apples high in tannins, cultivated especially for cider, can develop their broad aromas and will need longer to mature than the more acidic eating and cooking apples.
Choice of yeast
This step is probably the most widely discussed stage in cider making and as always there are many ways of going about it – but they essentially break down into using a cultured yeast or relying on wild fermentation.
In a similar manner to brewers, lots of cider makers will add a specifically chosen strain of yeast to carry out their fermentation. The choice of yeast will influence the characteristics of the final cider – for example, the use of wine yeast will produce a more ‘wine-like’ cider – bright with a juicy acidity.
The idea of using cultivated yeasts is to get consistency from batch to batch of both flavour and fermentation time. This approach is used by both small scale ‘craft’ producers as well as some large-scale cider makers who aim to complete the whole fermentation in just 7 days!
Many excellent ciders are made using commercial yeasts, sulphites will first be used to kill the wild yeasts. Some will delay this sulphiting for a few days to introduce a bit of the wild funk.
Minimum intervention wild ferment ciders and perries by producers such as Tom Oliver, Little Pomona and Ross Cider are produced differently.
In this spontaneous fermentation the yeast used to turn the apple sugars into alcohol exists within the fruits’ environment (in the air or on their skins) rather than grown in a lab. The resulting fermentation reflects the place and the environment which is part of what in the world of wine would be called ‘terroir’; and provides deeper, more natural flavours.
This is where tradition meets modernity. Cider makers such as Tom Oliver have championed the return to traditional wild ferment cider making, but to be presented in a modern way, much like the Natural Wine movement.
From the Orchard to the Barn
Wild yeasts are everywhere, on the apple skins and collecting in the orchard. With each pressing they stay on the cloths, the equipment and in the barn.
Just like in wine making or Belgian Lambic beer production the wild ferment ciders will take on a style reflecting the age and form of the orchard and the ‘in-house’ yeasts of the orchard and the barn.
Traditional producers of ‘Natural Cider’ are the spontaneous fermentation experts. Apple juice will ferment spontaneously with great ease using an ecological succession of yeasts.
The first yeasts from the orchard start a rapid fermentation but as alcohol levels develop, they die out and slower and stronger yeasts move in and finish off the primary fermentation stage.
Why are more modern ciders being made in the traditional way?
Firstly, the cider makers believe the depth of flavour and complexity achieved from a ‘wild’ or natural fermentation to be greater.
Secondly, commercial yeast strains have specific temperatures that they like to work in and require temperature control and a more ‘industrial’ environment.
Plus, on a slightly more philosophical level, the new modern traditionists are trying to make a purely Natural Cider and, to truly do that, they think you need to not only be using local fruit, but also local yeasts at local temperatures.
The search for consistency
The choice between wild ferment or use of cultivated yeasts is often influenced by the choice to create a consistent cider year on year or for a cider that expresses the place of its making, and which each year will reflect changes of in weather and environment. Many drinkers want their favourite cider to taste the same each year, others prefer the natural diversity of wild ferment. The use of specific yeasts can also produce ciders with a particular flavour profile, for example Hogan’s Cider use Brettanomyces yeast to create the sour flavours in their ‘Killer Sharp’ Cider; Hawkes Cider us a Sauvignon Blanc yeast in their Soul Trader Cider, to add citrus flavours to the Braeburn apple; others use Champagne yeasts to produce Traditional Method sparkling ciders..
The modern craft cider makers ambition
The modern craft cider makers ambition to express the flavours of the chosen apples or pears and to make a cider that truly reflects their local environment, their terroir if you like.
Part Three of this series – Process and styles – will appear in the June 2020 issue of Beer Buzz
All photos from Ross on Wye Cider and Perry and Little Pomona Cider. Copyright.