Off Flavors on RIMS Setup - Tannins?

[joety]

I am really frustrated with my new brew rig. I have made a number of changes and still have an off flavor in all the beers. From searching around here I wonder if it's not tannins. I am theorizing that the RIMS action is more efficient than my old mashing technique (coolers) so by the time I go to fly sparge, I should be using less water and add fresh water directly to the BK to hit my pre-boil volume. I never did this with the old setup, no matter how big or small the beer.

Did anyone else experience this when switching from coolers to a RIMS setup?

 

[MalFet]

What kind of efficiency are you getting? You'd have to be hitting pretty high for that to be the problem, I reckon.

 

[joety]

Mid-Eighties, but who's to say I'm measuring it correctly. I have a ton of dead space under the false bottom, lots of tubing, etc.

I am going to have some fellow home brewers sample the beer and see if they agree it's tannins. If so, I will cut the sparge water from 14.5 gallons down to 8 and add 5.2 stabilizer to the HLT before sparging (I already use it in the mash). I will try to keep an eye on the gravity of the runoff as well.

 

[joety]

It's present in all eight beers I've brewed on the new setup, and I never experienced it on the 40 beers on the old setup. I am religious about cleaning the system after brewing and I use a boiler on brew day morning to steam clean the RIMS tube and CFC.