I have heard that when sparging you should stop once the runnings fall to 1.010. Does this apply when batch sparging. I have just brewed a batch where the sparge was 17l I decided to split it into 2 and I did a 9l then 8l sparge. i checked the gravity of both sparges the first was about 1..030 the second 1.010. the second sparge tasted bad, quite harsh and i thought maybe i had extracted tannins. so i ditched it and made up the rest with water and still almost hit my OG. Not sure if this makes a difference or not but I use a nylon mesh bag instead of a manifold.
Should i have chucked the second lot of sparged wort. Is 1.010 too low?
Also I didn't quite get the temp up to 168 for my sparge instead it was around 164/165 could this have effected anything?