It's kept its shape more than I would've expected.
ご質問ありがとうございます。
「おもったより」はmore than I thoughtとかmore than I had expectedとかmore than I would've expectedなどに訳せます。英語では日本語と逆に最後に書いていますね。
例文:I heard the Fesikh is broken down by fermentation, it holds its shape more than I would've expected.
ご参考になれば幸いです。