Set in the beautiful Norman countryside, Domaine Drouin is of an average size for most artisan cider and calvados producers. They process close to 200 tonnes of apples per year at their bucolic facility. They have a pretty standard processing operation for what we have seen in Normandy and Brittany. They bring in machine harvested fruit from the ground as it falls off the standard trees throughout the season.
The fruit is processed same day or next day after harvest. The apples are ground through a mill and pressed. There is no specific extended maceration besides the default several hours of rest while the previous press is finishing. Calcium chloride and PME is used to achieve a chapeau brun. There tanks are narrow, high 2000L tanks. We were told that you can not successfully keeve in tanks bigger than 5000L, however we know this to be untrue as we saw keeving tanks up to 300,000L in action and heard of producers using 500,000L tanks. The juice is kept between 8C-12C while the chapeau brun is being formed. After a complete formation and the presence of clarified juice under the cap, the cider is racked into secondary vessels and allow continue to ferment. Racking and partial filtration are used to keep the speed of the fermentation in check. When the cider drops to the appropriate sugar level for the specific style (brut, demi-sec, etc), then the cider is filtered completely to halt fermentation. They then send samples of the cider to a wine lab to check if the cider, once packaged, will re-ferment partially then STOP due to lack of nitrogen. If the lab says the cider won't stop, they will have to reduce nitrogen in the cider by allowing fermentation to continue again, and filtering another time. The producer expected a 10g/L drop in sugar levels once the cider was packaged (for carbonation).
Of note, Domaine Drouin did seem to focus much of their efforts into Calvados production.