SUMMARY
Indonesia is one of the main cacao producers in the world. Indonesian cacao product is, however, relatively of low quality. Quality improvement of cacao beans is thus needed to increase added value of the product through such method as fermentation using bacteria and yeast. This study was conducted using four fermentation treatments, namely F1 (spontaneous fermentation without the addition of inoculum), F2 (addition of lactic acid bacteria inoculum), F3 (addition of yeast inoculum), F4 (addition of mixed lactic acid bacteria and yeast inoculum). The fermentation was carried out for 5 days. The parameters measured were the microbial cell number, pH, ethanol, total reducing sugar, and total acid concentration, as well as cacao seed quality. Results showed that, compared to the other treatments, the F4 treatment gave the best result, namely 83% of the cacao seeds being fermented, 2% non-fermented, 14% unfermented, 1% moldy, and 2% germinated. The liquid produced during the fermentation contained the highest reducing sugar of 123.38 mg·mL-1, the highest total acid of 24.42 mg·mL-1, and 3.57% ethanol. Indonesia adalah salah satu penghasil kakao utama di dunia. Namun berdasarkan mutu, produk kakao Indonesia masih relatif tergolong rendah. Peningkatan kualitas biji kakao diperlukan untuk memberikan nilai tambah pada produk melalui metode seperti fermentasi menggunakan bakteri dan khamir. Penelitian ini dilakukan dengan empat perlakuan fermentasi yaitu F1 (fermentasi secara spontan tanpa penambahan inokulum), F2 (dengan penambahan inokulum bakteri asam laktat (BAL)), F3 (dengan penambahan inokulum khamir), F4 (dengan penambahan inokulum campuran bakteri asam laktat dan khamir). Fermentasi dilakukan selama 5 hari, dan parameter yang diukur selama fermentasi adalah jumlah mikroba, pH, kadar etanol, gula pereduksi, total asam serta kualitas biji. Hasil menunjukkan bahwa, dibandingkan perlakuan lainnya, perlakuan F4 memberikan hasil terbaik yaitu 83% biji terfermentasi, 2% tidak terfermentasi, 14% terfermentasi sebagian, 1% berjamur, dan 2% berkecambah. Cairan fermentasi tersebut mengandung gula reduksi yang paling tinggi 123,38 mg·mL-1, total asam tertinggi 24,42 mg·mL-1, dan kadar etanol mencapai 3,57%.