so in VST coffee tools / espresso mode.
Calculation of extraction yield i believe is
Brewed coffee x TDS℅ / ground coffee dose .
For instance
40 g x 10(tds%) / 20( dose) = 20 % yield .
How come coffee tools(espresso mode) come out as 20.73 % ??
What parameter am i missing ?
It’s only 20%EY if there is no moisture or CO2 in your coffee dose. Note values for CO2 0.5% & MOIST 3% on right hand side.
Moisture in roasted coffee is well established & discussed in many papers going back to 1953 at least (Schwartzman), CO2 parameters are discussed in Illy’s book, for example.
In dehydration (the datum for coffee tools), it’s a good idea to establish how much of your soluble material is ‘something else’.
In terms of consistency, it doesn’t much matter whether you leave the pre-sets as they are, or set to “0” (or adjust either to add up to 3.5% total), but as you seem to trust the software, you might assume that these values were decided upon for good reason.
Ahh ofcourse … Dohh…
. thanx Mark 
Did not give it a thought in terms of consistency… Was just curious as to what i was missing in the equation