production
Washback
No legal definition
The fermentation vessel — traditionally Oregon pine or larch, now often stainless steel — in which cooled wort is fermented by yeast into wash.
Not a legal term
No whisky regulation in Scotland, Ireland, the United States, the EU or Japan defines this. It is a trade or marketing term, so it is only actionable if its use is actively misleading.
Worth knowing
Wooden washbacks cannot be sterilised the way steel can; the resident bacterial flora surviving in the wood contributes to lactic fermentation in long fermentations, a flavour effect distinct from the wood itself.
Related terms
Last reviewed 2026-07-30 · All glossary terms