Originally Posted by MatthewDLW3
Ok, I know there are quite a few threads on decoction mashing and tannins but was wondering if anyone could please explain why you don't extract tannins from decoction mashing but you would, say if you mashed at 190 degrees for 60 minutes? I know everyone just says ph and temp but just looking for more of an explanation. Did my first decoction last week with my first ever lager as well. It was a triple decoction (figured go big or go home!). I know I put some water in at almost room temp for a while (70 degree ish). Then added a little hotter water for a short while. Then started the triple decoction method. Does this adding low temp water make the ph of the wort to the point that tannins will not be extracted? Enjoyed the process but just really wondering about the science behind it. Thanks to anyone who can help.
You don't extract tannins in a decoction becasue tannin extraction has almost everything to do with pH and little to do with temps. The pH is low enough in the mash that you don't get excessive tannins from boiling the grain.
You won't get tannins from mashing at 190F is your pH is good.
If anything, adding water will raise your pH, not lower it. But if it's not too much water, it won't make much difference.