Excessive tannins

I've been brewing for a few years now. I've always batch sparged in the past and recently switched over to fly sparging as i finished building my vertical brew stand. My firt two batches on my new system have come out VERY astringent and more chill hazed than usual.

My crush is good and efficiency is where it should be (75-78%). I brew with RO water with salts added to the mash, sparge with RO, and add the remaining salts to the brew kettle.

I currently don't have a way to verify ph but I think I'm over sparging some way or another. My sparge rate is approximately 1.5 qt/minute with 168 degree water.

Shouldn't my RO fly sparge maintain a low enough ph to not extract tannins and phenols or should I try to dissolve the remaining salts to my sparge water to lower ph?

One thing to check is your final runnings - supposedly below 1.008 (I think, from Palmer) you can get tannin extraction.

Frodo said:

One thing to check is your final runnings - supposedly below 1.008 (I think, from Palmer) you can get tannin extraction.

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Isn't that because by that point of the sparge the mash ph has risen?

You could try treating your sparge water with phosphoric or lactic acid to drop the pH. Also, on the back end you could try adding gelatin. It's supposed to help remove some tannins.

JJL said:

You could try treating your sparge water with phosphoric or lactic acid to drop the pH. Also, on the back end you could try adding gelatin. It's supposed to help remove some tannins.

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Is there any harm in lowering my sparge water ph and then adding the other portion of my salts to the kettle (which would lower the ph even more)? In other words, is there any harm to the finished product with having my collected wort ph extremely low once I have collected it all in the boil kettle?

I bought a digital pH meter similar to this one on Ebay (http://www.ebay.com/itm/2-in-1-Wate..._Automotive_Tools&hash=item2c687e7f1a&vxp=mtr) because I suspected a problem with my water. This morning as I was brewing I collected a sample of wort just after doughing in and found a pH of 6.4. I had plenty of time to stir in some acid blend which a second sample revealed that it had brought the pH down to 5.2. For that much money I felt like I had made a good investment. It comes with calibration acids and I did verify calibration before I sampled since it had been over 4 months since using it and the calibration was right on.

d_striker said:

Is there any harm in lowering my sparge water ph and then adding the other portion of my salts to the kettle (which would lower the ph even more)? In other words, is there any harm to the finished product with having my collected wort ph extremely low once I have collected it all in the boil kettle?

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The salts being added to the kettle won't lower the pH. The only reason they do that in the mash is because they react with the malt to create acid, dropping the pH.

Polyclar will also work to remove tannins from your brew at the back end. Add a few days before bottling/kegging and it will make a difference.

bosco

boscobeans said:

Polyclar will also work to remove tannins from your brew at the back end. Add a few days before bottling/kegging and it will make a difference.

bosco

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I tried that on the last batch. I chilled to 28 degrees and added Polyclar. Helped a little with the haze but still tastes very astringent.

I would prefer to fix the problem upstream.

I guess I'm still confused as to why I'm extracting excessive tannins when sparging with RO water.

I thought RO water had no buffering capacity which means my mash bed pH should not rise. Or am I all wet here?

d_striker said:

I guess I'm still confused as to why I'm extracting excessive tannins when sparging with RO water.

I thought RO water had no buffering capacity which means my mash bed pH should not rise. Or am I all wet here?

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you're correct. Sparging with RO water should not raise the pH above 6.

What is the source of your RO water? I wonder if you can check with a TDS meter and make sure the RO water's membrane/process is working.

Yooper said:

you're correct. Sparging with RO water should not raise the pH above 6.

What is the source of your RO water? I wonder if you can check with a TDS meter and make sure the RO water's membrane/process is working.

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I have a small 5 stage portable filter from purewaterclub.com.

The water is run through a series of carbon filters, RO filter, and DI filter. I don't have a TDS meter but I see where you're going.

I just found this on a fish tank forum regarding these filters:

"One other thing you will want to do to help the unit be more efficient is to turn the DI canister (the clear one) vertically so that the water doesn't "channel" through the DI resin. You want the water to come in the bottom, exit out the top. Any other setup and it tends to channel and you will see elevated TDS readings from the output water because the DI resin isn't doing its job."


I have the DI filter oriented vertically but I'm not sure if the exit is on top...I'll have to check later.