Originally posted by LeroyC
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Underextraction vs Overextraction!
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Is it starting to make sense Simon? I've been sifting through old BH and Jimseven posts to see if there's anything that could help you. The only one that really stuck out was this BH blog post - https://baristahustle.com/blogs/bari...cipes-strength The last section in particular, called "'The Perfect Strength' could be useful.Originally posted by simonsk8r View PostAh that's brilliant, thanks so much for that, will study that like crazy.
Hmm, I can understand how something can be underextracted and strong (stopping a shot really short, much less diluted), and overextracted but weak (a shot left going far too long), but the chart doesn't seem to be displaying that...
The green diagonal line seems to suggest that the longer you leave a shot the stronger it gets ad infinitum...
Also I've never quite understood the difference between TDS and extraction...
Total Dissolved Solids sounds like it should be what you're "extracting" from coffee (between the ideal 18-22%), yet it seems to be a different figure/equation altogether...
According to the graph, TDS seems to describe weak--->strong, whereas extraction seems to describe amount of flavour components in coffee as the shot progresses...
Am I on the right track in any sense at all? Haha...
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In the classic definition, a double espresso would measure 60 ml volume. Because this includes crema, which has a far lower density than the actual liquid, this would be way less than 60 grams already. Since different coffees produce different amounts of crema, it makes more sense to define a shot by mass rather than volume. 18 grams of ground coffee "should" produce a 36 grams shot, but plenty of people gravitate towards a more concentrated version of espresso.Originally posted by saeco_user View PostI would have thought 18g is a double meaning the espresso shot will be closer to 60g hence the TDS is ballpark correct
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Ahhh a little bit... have read these posts a few times over and I think I get it maybe haha.. I did understand bits of it, I'll have a look at the article, thanks so much for looking for me I do appreciate it.
So TDS is a ratio expressed as a percentage of espresso solubles (that which can be dissolved and taken away by the water) divided by the espresso mass itself, to get a percentage of all the dissolved solids within the beverage, ie the percentage in an espresso of the total dissolved solids relative to the total espresso mass extracted (ideally 8-12%?)?
Whereas extraction percentage is just the percentage of solubles extracted from the grounds (but leaving total espresso mass beverage out of it)....? )(ideally between 18-22%)?
Thanks everyone for all your help, I'm sure it'll click haha, whether it's something that will help me in espresso extractions or not I'm too not sure unless I had a refractometer... it is fascinating nevertheless!
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Ah cool okay haha *fist pumps*, thanks mate.
And that makes sense that the TDS for espresso is much much higher compared to filter brewed coffee ,the filter brew would be less solubles (or moreso same/similar solubles extracted, but less concentration) based on the sheer amount of extra water used.
Now how to translate all this into useable practical knowledge haha, I'll research BH, they usually are pretty good with that
(I just wrote a whole bit and deleted about why I didn't understand why the chart was showing TDS to be higher for filter brews but didn't realise the percentages were 1.2%, thought it said 12% XD my bad!)
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Yes, you're right, the chart shows a filter coffee and I should have stated so.Originally posted by MrJack View PostFYI - Espresso is WAAAY off the scale of that chart.
18 g (ground coffee) * 20% extracted = 3.6g (coffee dissolved)
3.6 g (coffee dissolved) / 30g (espresso) = 12% TDS
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