How the TDS of the Interstitial Liquid Changes Readings
To give you a rough idea, imagine you made a pour-over using a brew ratio of 15–250g. Once brewed it had a TDS of 1.4% and beverage weight was 220g. You know you poured 250ml into the brew so the weight of the liquid left over will be the remaining 30ml, plus a tiny amount of additional liquid weight added to this from the dissolved coffee solids it has retained. Let’s say the TDS of this liquid was 0.8%, which we frequently find the very final drips of a pour-over actually demonstrates.
Now think about the extracted mass again:
(Upper arrow) In the interstitial liquid,