Tannin in mash/sparge

[oxonbrew]

Hi All,

My last two all grain batches seem to suffer from a very bitter aftertaste. I'm wondering if this is due to tannin extraction. Both have used wheat/pale malts. I've sparged at ~170F but I'm wondering if the ph of the mash/sparge increased to a high level.

So my questions...

1) How do I lower ph in my mash/sparge water?
2) What should I use to test ph? (I have a digital meter but I think it's producing incorrect readings).

Thanks for any help!

 

[grathan]

Did you follow the instructions for the meter? Acid will lower pH. Lactic is common in brewing, but citric and phosphoric are used as well.

PH can cause problems if it goes too low as well. You could try a couple ml in sparge water and see what happens though.

 

[Weezy]

Are you certain it's pH? All your saying is that your last two batches have been off so we're assuming your prior efforts have been good and the only difference here is essentially wheat grain? This seems odd.

Regardless,
1. grathan answered this.
2. You can check your pH meter by testing it on buffer solutions: http://www.amazon.com/s/?ie=UTF8&ke...vptwo=&hvqmt=b&hvdev=c&ref=pd_sl_67bk1589gq_b

 

[Wynne-R]

Here’s a good place to start: https://www.homebrewtalk.com/f128/ph-meter-calibration-302256/
and
http://byo.com/stories/item/1264-preventing-beer-slime--reducing-tannins-but-not-flavor-mr-wizard

A pH meter is pretty useless without calibration. Also, if you’re not using storage solution, you should be. Gotta keep that probe wet.

Chloramine is something else to consider. If you’re using tapwater, 1/4 of a Campden tablet will neutralize chlorine or chloramine. Either of these disinfectants will give you an unpleasant mediciny taste which could be construed as bitter.

 

[oxonbrew]

Thanks so much for all of the useful advice.

To add a bit more to my original post, I did calibrate my meter, however I couldn't set the meter to the two buffer values (I think 4 and 6.8 ish?) So I have a feeling the meter is bad (It is old, maybe 5 years old). I've not used a storage solution, maybe this has caused my problem.

I'm not certain this is caused by ph, I've brewed 8 all grain batches now and I've only had problems with the last two, both of which have been pale beers (6-8 EBC). Two other things have changed, I've moved house - only by 8 miles and the water is still as hard as nails. The other thing is my supplier, I've no reason to think that there is anything wrong with the malt/hops from the new supplier.
The first "off" batch was treated with salts using a water calculator and 1/4 campden tablet. The other had no treatment but the water was filtered through a water filter jug (resins and active carbon).

So one more question, would any of the suggested acids, Lactic, Citric or Phosphoric leave any residual taste in the beer?

Thanks again!

 

[Wynne-R]

Pales are less acidic than darker grists, so that points to pH. I make pales with moderately hard water and I need acid for the sparge, the mash is OK.

Phosphoric acid doesn’t have a taste, because phosphate is already in the mash. Lactic has a threshold, but it’s pretty high, and the flavor isn’t that bad. Citric I don’t know.

If your electrode went dry, it’ll take a few days for it come back, if it ever does. Storage solution is ideal, but water is better than nothing. Also how fresh are your buffers? They’re good for about a year, there should be a date on them.If you can get your hands on a water report, you could use one of the spreadsheets, Bru’nwater or EZ Water, or my favorite online calculator http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/#

 

[mabrungard]

Excess alkalinity in either the mashing or sparging water is a great way to draw tannins into your wort. Another way is to oversparge.

Oversparging is currently my problem. I've been trying to cut off the sparging water so that my final runnings are no lower than 2 brix. But I keep getting distracted while running water out of the HLT. I'm just going to have to kick my own a$$ and not get distracted at this critical time in the brewing process. Bottom line: don't oversparge.

 

[oxonbrew]

Thanks again for all of the help.

For my first batch I used my water report and the following water calculator:

http://www.jimsbeerkit.co.uk/water/water.html

I added the salts but also added CRS to my sparge water, I'm wondering if this might have caused the problems. Certainly the tannic/mineral taste is more pronounced in the first of these batches.

I do watch my s.g. as I sparge and tend to take a reading at 2 litre intervals. I stop my sparge when I get close to 1010 (s.g.) So I'm guessing all is ok there.

I made the buffers up from a sealed package, so I'm guessing they are ok. So I think my next course of action is to replace my meter and take better care of it

Could anybody suggest a good meter please? Or what features I should be looking for? Would ebay be a place to get one?

Cheers!

 

[Wynne-R]

Many of us (myself included) have had good results with the Milwaukee MW101 or MW102. Yooper had horrible luck with the Milwaukee 56. Hannas are reportedly good.

My guess is that separate probes work better than the all in one pocket-size designs. If you miniaturize while holding the cost, something’s got to give. I like that I don’t have to mess with the stupid CR2032 battery.

Look for one with .01 resolution. That may seem like overkill, but it’s not. Suppose you had a reading of 5.4. That’s ± .1, a pretty big neighborhood.

On your sparge, keep it below pH 6 and 170F. Martin says keep it above 2 Brix, whatever that is. I’ve heard 1.010, I think that’s about the same.

 

[cosmo]

Excess alkalinity in either the mashing or sparging water is a great way to draw tannins into your wort. Another way is to oversparge.

Oversparging is currently my problem. I've been trying to cut off the sparging water so that my final runnings are no lower than 2 brix. But I keep getting distracted while running water out of the HLT. I'm just going to have to kick my own a$$ and not get distracted at this critical time in the brewing process. Bottom line: don't oversparge.

Martin,
I hope this is not too far off topic. Is oversparging a concern when batch sparging, or just with fly sparging? Not sure if I should limit my batch sparge water and add top-off to the boil. Thanks.

 

[Denny]

Martin,
I hope this is not too far off topic. Is oversparging a concern when batch sparging, or just with fly sparging? Not sure if I should limit my batch sparge water and add top-off to the boil. Thanks.

You _can_ oversparge when batch sparging, but it's damn hard to do and you almost have to be trying to do it.

To the OP....tannins are not a taste...they are a dry mouthfeel, like sucking on a grape skin. If you're tasting bitterness, the problem is not tannin.

 

[Wynne-R]

It’s not that simple Denny. Tannins are not a thing, but a group of things, a category. What we (incorrectly) call tannin in beer is actually a bunch of different polyphenols, some of which are tannins.

Improper sparging will cause astringency as well as harsh or bitter flavors. I don’t know if they’re tannins or not, but the cure is the same.

Sparge should be well below pH 6.0, 170° F and over 1.010 specific gravity.

 

[oxonbrew]

Hi,

Thanks to you all for the responses (and good question about batch sparging - which I also do sometimes).

My feeling is that my off taste has been caused by several things, temperature, incorrect salts, ph... I do notice a significant chill-haze which I think I read can be caused by polyphenols.

Reading through your responses I've realized that my control of PH and temps isn't great. I have a ph meter that I can't calibrate and a thermometer that is accurate to +/- 0.5C (~+/-1F ?).

Thanks for the advice about ph meters. If I understand Wynne-R post I see that I need a ph meter that has a good accuracy (I notice when looking on websites this can be different to "resolution") so +/- 0.1ph accuracy would mean (for example) a reading of 5.4 could actually be somewhere between 5.3-5.5. So +/- 0.1 accuracy would be 5.39-5.41 -- Much better

So my next question: To get an accurate mash temp do I need to use a pid/herms type system? How accurate are these? Or can I just get a good thermometer? I read some other threads that recommend "Thermapen" but these seem to be accurate to +/- 0.4C (152-154F at 153F).

Thanks again for all of the help!

 

[Denny]

I use a dial thermometer that I calibrate every few brews with a lab thermometer. When I mash in I keep stirring until I get a consistent temp no matter where or how deep I measure the temp.

 

[Wynne-R]

Oxonbrew, ± .4° C is smokin’ hot. That’s worst case, typical readings are better. Most thermometers aren’t even rated. As you mentioned, resolution is a whole different animal than accuracy. A lot of people miss that and manufacturers are happy to let them.

Plenty of people are 2-3 degrees off and don’t even know it. As long as the relative indication is good, it’s usable. If you’re within a degree Fahrenheit, that’s about as good as it gets.

I checked into a higher resolution thermometer and they are hundreds of dollars.

 

[oxonbrew]

Thanks Wynne, Denny - again very helpful.

I guess I had in mind that if I want to replicate recipes or share my recipes with others we all need to agree on the same temps/ph to get the same results.
Also if I mash at different temps to get a more/less fermentable wort I really need an accurate temp reading (don't I??).

I've just looked at a lab (distillation type) thermometer on the internet and its a bit out of my price range. Are thermocouple based thermometers more accurate? I see lots of k-type ones that seem to be a reasonable price.

Cheers!

 

[Denny]

Thanks Wynne, Denny - again very helpful.

I guess I had in mind that if I want to replicate recipes or share my recipes with others we all need to agree on the same temps/ph to get the same results.
Also if I mash at different temps to get a more/less fermentable wort I really need an accurate temp reading (don't I??).

I've just looked at a lab (distillation type) thermometer on the internet and its a bit out of my price range. Are thermocouple based thermometers more accurate? I see lots of k-type ones that seem to be a reasonable price.

Cheers!

I bought one of these after it was highly recommended by a chemist friend...

http://www.amazon.com/dp/B001UHS2G6/?tag=skimlinks_replacement-20

 

[kh54s10]

My Thermapen certificate states the following: Uncertainty of Calibration: +/- 0.7 degrees F +/- 1 digit. So, it should be less than 1 degree F off.

I feel it was well worth the money and is by far the fastest thermometer I have in settling in on the temperature.