Fault
Soapy
A soapy note from fatty acids released by yeast left too long on the trub, or from detergent residue in glassware.
What it tastes and smells like
Responsible compound: fatty acids.
If you are drinking it
A soapy taste is often the glass rather than the beer. Rinse thoroughly and pour again before concluding the beer is at fault.
- Rinse glasses thoroughly and air-dry them. (prevents)
Not a safety issue. Beer’s alcohol, hop compounds and low pH make it inhospitable to organisms that cause illness.
What causes it
| Cause | Stage | How often | Who can act |
|---|---|---|---|
| Beer left on the yeast bed long enough that fatty acids are released and converted to soap-like compounds. | fermentation | most common | brewer |
| Washing-up liquid not fully rinsed from a glass. | dispense | common | consumer |
If you are brewing it
- Brewer: Rack off the yeast within a couple of weeks of terminal gravity. (prevents)
Where in the process this comes from
Steps that can produce this fault when they go wrong. Each links to what the step is for and how it is controlled.
- Primary fermentation — Convert wort sugars into ethanol, carbon dioxide and the esters, phenols and higher alcohols that give beer much of its character.
Often confused with
- Poor head retention — head collapses within seconds, no lacing on the glass