Sampling was repeated every 10 min on five consecutive occasions to constitute a sampling period. The effect of three different target FES pHs was studied in 1 day, and the factory was flushed out at the target FES pH at least 2 h before the next sampling period. Each sampling period was repeated three times across the grinding season: early (Oct 2), mid (Nov 6), and late (Dec 11) season, for adequate coverage of environmental variation in cane quality.