The definition of maceration is to soften or separate. With regards to apples and pears, this process occurs after the apples have been milled or crushed but before the pomace is pressed. One of its key goals is to break down the pectin found in the fruit. This aids in cider clarity and can add aromatic compounds. However, it goes well beyond the removal of pectin. It impacts many of the organoleptic characteristics of your cider. It’s important to remember that maceration of the apple pomace will have similar results as maceration of grapes in the wine making process. White wines are generally fruity, pale in color, and low in phenolic compounds like tannins. They usually spend little to no time being macerated. Rosé wines are similar but with some reddish hues because they spend a little time being macerated. Red wines spend the most time being macerated but its not just color that is transferred. It includes many of the polyphenols desired for red wine. This maceration and co-fermentation with the skins and seeds transfers many compounds to the wine. With some adjustments, this same process can be executed for cider with apple pomace.
The apples are ground or milled into a pomace. Besides breaking the apple flesh into small pieces that are capable of being pressed, it also starts the release of juice and pectins from the flesh. In additional it begins transferring polyphenols into the juice. In general, the longer you macerate, the more of these compounds you transfer. There are two main phenolic compounds that you will find in an apple and are transferred during maceration: phenolic acids and flavonoids(1). Within these groups, there are several dominate compounds.
- 5-caffeoylquinic acid – A phenolic compound with bitterness that creates caffeic acid, a strong antioxidant, anti-inflammatory, and anti-diabetic compound.
- p-coumaroylquinic acid – A compound known for bitterness.
- flavan-3-ols – Initially colorless, with polymerization, they become tannins and red hued.
- dihydrochalcones – Apples present one of the greatest sources for dihydrochalcones, which are strong antioxidants.
- flavonols – Primary found in the peel, these compounds are known for their strong antioxidant capabilities.
- anthocyanins – Primary found in the peel, these compounds create color and add some astringency.
If you read some of the older research, it indicates that maceration can lead to a loss of tannins if left too long. However, as Zielinski and associates(1), M.-A. Ducasse and associates(2), and other researches have found, maceration time and enzyme treatments tend to increase the polyphenols transfer into cider. What reduces these phenolic compounds is the oxidation that can occur. This is dependent on exposure to oxygen and usually impacts easily oxidized compounds, usually tannins. This is the browning you see in pomace and juice. However, this browning is often from weak tannins that are precipitated out during fermentation. It is an example of how you can manipulate the color of your cider. It also highlights the difference between apple pomace maceration and wine maceration. With red wine, you begin the fermentation process during maceration, which reduces the oxygen exposure and mimics my recommended practice of adding peels to your primary fermentation process. One thing my research has highlighted is that we only understand a small portion of the phenolic reactions and impact maceration has on the cider making process. More research is definitely needed but one of those challenges is finding accurate and cost effective ways to measure the polyphenols and their reactions at different steps in the fermentation process. That means there are more topics to research and trial.
(1) A. Zielinski & associates, Effect of mash maceration and ripening stage of apples on phenolic compounds and antioxidant power of cloudy juices: A study using chemometrics, LWT – Food Science and Technology 57, 2014
(2) M.-A. Ducasse & associates, Effect of macerating enzyme treatment on the polyphenol and polysaccharide composition of red wines, Food Chemistry 118, 2010
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