How should wort taste (Pre-boil)

[kandrew54]

Curious as to what flavour I should expect from the Mash run off.
Is there a point at which the flavour starts to change to indicate you should stop sparging?

[slothrob]

The wort will get progressively less sweet as you take runnings. Eventually you should be able to taste a rising astringency. You can also monitor the gravity of the runnings and stop before they get too low. That cut off is frequently listed as about 1.010, but I've also read that tannin extraction can start to rise significantly below about 1.018.

It can be difficult to taste astringency in the unfermented wort through the sweetness.