Blonding is when the espresso stream changes from dark reddish-brown to pale straw or white.
What it means
The soluble material is running out. What comes after blonding is mostly water carrying the last, bitter, drying compounds.
Continuing past it dilutes the shot and adds bitterness at the same time.
When it should happen
For a 1:2 shot, blonding typically starts around 20 to 25 seconds, near the end of the yield.
Blonding at 10 seconds means the extraction is running far too fast — grind finer, or you are channelling.
No blonding by 40 seconds means the grind is too fine and the shot is choking.
Using it
Many baristas stop the shot by blonding rather than by weight or time — particularly with unfamiliar coffee.
In practice, weighing the yield is more repeatable. Use blonding as a cross-check: if you hit 36 g and the stream is still dark, you could go longer.
Why a bottomless portafilter helps
You can see the whole bottom of the basket, so blonding, channelling and uneven flow are all visible. A spouted portafilter hides everything.
Not a fault by itself
Every shot blondes eventually. The question is only whether it happens at the right moment relative to your target yield.
Last reviewed 8 August 2026