Asam sunti is a typical seasoning Aceh cuisine made by processed belimbing wiluh (Averhoa bilimbi. L) in the form of semi-wet. Making asam sunti in powder form as well as other spices such as pepper, turmeric, and ginger others is expected to simplify and expand the asam sunti market as spice. The aim of this research were to make asam sunti powder, to analyze the effect of packing type on the change of water content of asam sunti powder, and to the estimation of shelf life of asam sunti powder in the packaging. Preparation of asam sunti powder was carried out by drieying a semi-wet asam sunti at temperature 70°C for 12 hours. Dried asam sunti was blended and sieved (80 mesh). Measurement of isotherm sorption properties was done using the salts of NaOH (6.9%), NaBr (56%), NaNO2 (64%), NaCl (75.3%), and KCl (83.6%) to regulate the humidity. The packaging tested for asam sunti powder storage was aluminum foil, HDPE and PP. Critical water content to a determine of shelf life of asam sunti powder at 21.26% with powder conditions starting to clot and not accepted by consumers. The estimation of shelf life of asam sunti powder with sorption method for aluminum foil, PP and HDPE packaging were 541.81, 506.83 and 369.24 days at 75% RH storage respectively, while RH of 83% was 364.12, 337.50 and 245.88 days. These results indicate that the best packaging for asam sunti powder was aluminum foil.AbstrakAsam sunti merupakan bumbu khas masakan aceh yang terbuat dari olahan belimbing wuluh dalam bentuk semi basah. Membuat asam sunti dalam bentuk bubuk seperti halnya bumbu lain yaitu lada, kunyit, jahe bubuk, dan yang lainnya diharapkan memudahkan dan memperluas pasar asam sunti sebagai bumbu masakan. Penelitian ini bertujuan menganalisa pengaruh jenis kemasan terhadap perubahan kadar air asam sunti bubuk dan pendugaan umur simpan asam sunti bubuk dalam kemasan. Pembuatan asam sunti bubuk dilakukan dengan pengeringan suhu 70oC selama 12 jam. Asam sunti kering diblender dan diayak (80 mesh). Pengukuran sifat sorpsi isotermis dilakukan menggunakan garam NaOH (6.9%), NaBr (56%), NaNO2 (64%), NaCl (75.3%), dan KCl (83.6%) untuk mengatur kelembaban. Kemasan yang diuji untuk penyimpanan adalah aluminium foil, HDPE dan PP. Kadar air kritis sebagai penentu umur simpan pada nilai 21.26% dengan kondisi bubuk mulai menggumpal dan tidak disukai konsumen. Pendugaan umur simpan asam sunti bubuk dengan metode sorpsi untuk kemasan aluminium foil, HDPE dan PP berturutturut adalah 541.81, 506.83 dan 369.24 hari pada penyimpanan RH 75%, sedang pada penyimpanan RH 83% berturut-turut 364.12, 337.50 dan 245.88 hari. Hasil ini menunjukkan bahwa kemasan yang terbaik untuk menyimpan asam sunti bubuk adalah jenis aluminium foil.