Slow espresso shot showing blonding

An espresso extraction on a Rancilio Silvia showing the various stages of extraction including the onset of blonding.

Category:

Howto & Style

Tags:

• Rancilio
• Silvia
• espresso
• blonding
• extraction
• coffee

[snedie69er]

So, I'm new to the whole self made coffee scene.

What exactly is blonding?

I own a fairly cheap expresso machine (£80), and up to now all my shots have been very bitter.

Any advice

[gregpullman]

Blonding is when the espresso turns from a dark hazelnut colour to a lighter 'blonde' yellow colour. While the shot will blonde during normal extraction as the oils are removed from the puck, blonding normally starts as a thin stream in the pour and indicates a section of the puck has become exhausted of 'goodness'. Bitterness normally comes with blonding so for max richness and smoothness it's a good idea to stop the shot at the onset of blonding, regardless of the volume of espresso extracted.

[snedie69er]

@gregpullman

Does this principle apply to normal coffee blends too, or are there differant signs to watch for?

And thanks for the reply :)

[gregpullman]

The principle would apply for all coffees. Some may blond earlier than others but the process of desaturating the puck of oils and volatiles remains the same, regardless of the beans that make up that puck.

[gregpullman]

This is from a double basket, hence the 60ml extraction. Blonding starts about the 14 second mark and is pretty obvious at 16 seconds. It's the light yellow stream amidst the darker espresso.

This was with very fresh beans (too fresh, less than a day out of roast) so blonding would be expected early given all the gas the beans would have still been releasing. After 3-4 days you could expect to get at least several more seconds of extraction before blonding.

[vasiasm]

greg this is a double or single ? What time you propose to stop? What time is the blonding point on this extraction.