First off a big thank you to everyone who contributed to the espresso poll. Â It closed out at just under 100 people giving their data. Â Out of this some data had to be ignored as it was clearly entered in error, leaving just over 90 espressos worth of information.
I am not a massive statistics expert – and I am grateful to Vince Fedele for taking the data and cleaning it up and doing some analysis on it.
To start with the easy stuff:
An interesting average espresso here – I would have suspected a slightly higher dose amongst readers of the blog, but a good number were dosing at around 14g for a double. Â The average shot size was good to see.
Average ground coffee weight: Â 17.2g
Average shot weight: Â 32.7g
Average shot time: 27s
This shot would have a brew ratio of 53% – for those unfamiliar with brew ratios (credit to Andy Schecter) – Brew ratios. (Old post)
For those of you out there playing the ExtractMojos for espresso, or have been interested in espresso strength and extraction, Vince did a simple calculation where we assumed that extraction was around 20% of the coffee (as people had dialled in for taste) and therefore the likely strength of the average espresso was 12.2%.
This is very interesting to me because the average is pretty much where I have really been enjoying espresso recently.
Reasons behind recipes
I asked people to state why they used the recipes they did. Â Here are the results:
A few surprises for me here:
Not many people use the roaster’s suggested brew recipe.
Flavour was a higher priority than texture. Â This is only unusual because we’re talking about brew espresso, whose key pleasure (in my opinion) is texture.
One other reason I wanted people to answer these questions is so I could group them and then analyze. Â One big surprise here for me. Â I took the top three answers (flavour group, balance group and texture group) and looked at their averages:
Average dose: Â 17.5g
Average shot weight: 30g
Brew ratio (strength): Â 66% (13.6% TDS expected) a
Average dose: Â 18.7g
Average shot weight: 33.4g
Brew ratio (strength): Â 60% (12.1% TDS expected)
Average dose: Â 16.7g
Average shot weight: 36.9g
Brew ratio (strength): Â 49% (9.9% TDS expected)
What do the above mean? Â First off I was very surprised by the texture group – they pulled the biggest shots, from the least coffee. Â Essentially they pulled the weakest shots (from which you’d expect the least texture). Â I expected texture focused people to pull shorter shots from more coffee, and yet the results are the opposite. Â The flavour group pulled the strongest, thickest shots and the flavour focused people were closer to the average (and how I like my espresso.)
I don’t mind admitting that I will have some preconceptions about how someone will brew espresso based on their starting dose. Â Generally I would expect a shorter shot to come from a higher dose. Â This has always seemed a little counter intuitive to me, because you have more coffee to extract so surely using less water will only make that more difficult.
I created a simple chart to see if my expectations were correct. Â I charted starting dose against brew ratio. Â This would mean that if people used more water with more coffee in a linear way then the data would essentially flat line. Â This was not the case:
As I expected there is an increase in brew ratio (a decrease in relative shot size) with an increased dose. Â However you can see the data is all over the place and there is a massive range of shots sizes being pulled from all doses.
From the above graph you can also see the distribution of the doses submitted in the survey. Â It may seem strange to see a range from 7g to 24g. Â The 7g entries were kept because the shot weight was clearly for a single espresso so didn’t affect the brew ratio calculation.
There is no right or wrong way to brew espresso. Â However, I can’t help but feel this might be one of those moments where the wisdom of crowds has come good. Â What I would appreciate is if the average espresso from the group is very different to your own – give it a try! Â I’d love to hear your opinions, whether you found anything better from trying to pull a good shot using 17-18g, pulling about 32-34g of water through it (brew on scales) and aim for about 25-28s. Â Let me know if you try it!
If I was going to do the survey again I would probably add a few more questions, and I hope to do another survey soon – perhaps about brewed coffee, or maybe espresso again. Â Your thoughts welcome.
- Again – to clarify: Â I couldn’t get people to measure the strength of their extracted shots, so it was assumed that if they tasted good they were extracting approx 20% of the ground coffee into the cup. Â Essentially this is something of a guess. (back)