The stainless steel outdoor fermentation vats are double lined in order to maintain temperature control. Quality is the same as in the case of indoor fermentation, but costs are much less.
室外醱酵桶以不鏽鋼製成，內有夾層隔離溫度，讓醱酵能在控制的溫度下進行，效果與傳統的室內醱酵設備相同，但可節省建築房舍的費用。