Bob_McBob wrote:The blog post is talking about extraction yield consistency. The shots were weighed to provide the beverage weight to calculate extraction from a TDS reading. I don't really follow anything in your reply unless you are categorically rejecting the notion that extraction yield is a meaningful measure of anything related to espresso, which is a whole different level of discussion.
I didn't realize they were calculating extractions. Nevertheless, while I don't reject the concept of calculating extraction from TDS; I think the current tech for doing this is far less accurate in terms of taste than just letting the shot blonde and tasting the result. But that is another story.
My more general point is very simple. Some espresso variables correlate directly and atemporally to taste; others correlate via complex differential equations. The ones that correlate directly should be set accurately at the outset; the ones that are bouncy-bounce systems should be regulated closed loop. That's why I weigh doses, but regulate the blonding (and now the flow) by eye.
Once LM comes out with flow and marginal extraction regulators, I'll happily buy their superauto. Then, I'll make a living letting people subscribe to get the proper brewing data for each new coffee.