Oxygenation taste in fermenting beer?

Guys,

Recently, A lot of my beers have been cursed with a taste that I used to contribute to oxidation. It is the sensation of dust in your mouth that develops on the finish of a beer on the back of my tonge. It would be fine if this was just oxidation since I would know to be more careful with the beer after fermentation, but I also started to notice this taste in young beer and lately even in beer that is still fermenting.

Any idea what that could be?

Kai

Oxidation is a cardboard-like flavor that takes months to develop. Sounds more like astringency, which is present the wort right at the beginning and becomes more pronounced as the sweetness is fermented out.

"Astringency: It is dry, kind of powdery and is often the result of steeping grains too long or when the pH of the mash exceeds the range of 5.2 - 5.6."

Astringency might be an option to. I have not (knowingly) tasted an astringency example yet. The beers I'm talking about definately have that powdery taste. But I'm not sure if it can come from the grain. My mash PH is always in the lower 5's, My mash-out/sparge temp doesn't go above 75*C and I even started to condition the grains so the husks don't shred as much as they uesed to. And I batch sparge. I'll have to check the PH for subsequent sparging batches though.

Maybe it's the hops. I have been working with one 1lb bag of Hallertauer Mittelfrueh for a while now. Hops are also known to add tannins to the beer. Some of them are necessary for a good hot break, but maybe the are present in excess.

Kai

Ive had a "powdery" sensation on a green beer once. But by the time it was completely finished that taste disapeared, and the beer turned out really well. Im not sure what exactly caused it though.

Get a black tea bag & boil it for 5 minutes in a cup of water. That's astringent.

I batch sparge & use pH 5.2 in the mash and the sparge.

I certainly have to explore the possibility of tannins from the grains a little more. My temperatures are below the critical temperature and I thought that my PH is fine too. But maybe the strips that I'm using are off. I'll be getting a PH meter for christmas, then I will know for sure what my mash PH is. Until then I will have to read more about water chemistry.

Kai

edit:
I just checked my PH strips (ColorPhast) and while they are pretty readable they seem to be off by a few 0.1 PH units. The reference was well and R/O water since I have a water report for both. I read ~5.5 on the RO water while the water report states 6.0. I also remember brewing a Dunkel with moderately hard water (~50mg/L HCO3) and the mash PH was ~5.0 which surprised me quite a bit. This Dunkel was brewed with a similar process and same hops as the other beers with the possible astringency problem and it doesn't show this astringency.

I'm going to brew an Alt this weekend (very similar grain bill as the Dunkel), but different hops and yeast and will see how this comes out. I'll also give the Helles another try with less alkaline water (I use R/O water + salts) and see if that fixes the problem.

I also made a cup of abused tea and gave it a taste. The dry taste from that tea developed on the sides and tip of the tonge. But the taste I get from the beer develops on the back of the tounge and seems different. While the tea gave me a sensation of dryness, the taste from the beer litterally gives me a sensation of dust. Not that I have tasted dust before, but that's how imagine dust would taste.

Kai

Kai, i used the cheap strips for a while and found they were off by a nice bit. What I thought to be 5.3 on my strip showed up as 5.9 on my meter.

Since getting the meter and adjusting to get 5.2 to 5.3 PH in my mash and using 5.2 PH stabalizer in my sparge water, my brews improved noticeably.

boo boo said:

Since getting the meter and adjusting to get 5.2 to 5.3 PH in my mash and using 5.2 PH stabalizer in my sparge water, my brews improved noticeably.

Click to expand...

Yes, I belive the same now.

When looking though my notes I found that beers, that had a measured mash PH of 5.0 had a 3-4% better efficiency than mashes that had a measured PH of 5.3. Since 5.0 is already outside the optimum for mashing, the efficiency should have been less. I also noticed a shorter conversion time for when the mash measures 5.0.

And the whole problem started with light beers when I started measuring the mash with ColorPhast strips, which I assumed to me more precise than lithmus paper and I tried to get my mashes into the 5.3 range. I really hope this mystey is solved now, but may end up dumping my Helles if it has a lot of astringency. It will have served as a large starter since I'm not very happy with its fermentation either.

Yes, I'm looking forward to that PH meter. It was actually more important than a refractometer for me since I can measure gravity pretty well with a hydrometer. I'm not a big fan of the 5.2 stuff though. I rather adjust the mash with the composition of the brewing water and acid malt if necessary.

Kai

So, you have decided the problem is ph? I have been trying to think what dust, back of the tongue could be. I haven't come up with anything yet, but astringent, as you say, is something I look for on the side and not the back, so I would not have gone down the ph road.

This problem interests me greatly. Are these batches all RO water with salt additions? How are you calculating your amounts? Is your water normally soft? The reason I ask is that my darker beers have never turned out to my taste. They're good but not to style. I have soft water with a PH of 4, most of the time. Because of fluctuations, (seasonal) in my well water I recently decided to go RO and build my water. I have only done one beer so far with my salted water and it is not done fermenting. I went to Burton water on a Rye IPA and I'm afraid London water might have been a better choice. The wort tasted bitter but then the IBUs were 84. I can brew great Wits and Kolsh, anything blond but my dark stuff is not what I want and I know it is the water. Look to sanitation very thoroughly. JZ claims many small off flavors are due to low level bacteria.

Musthavbeer said:

I have soft water with a PH of 4

Click to expand...

How are you measuring? I think a pH of 4 would make your mouth pucker! Not quite as acidic as a lemon, but it's approaching it..

I,ve been using PH strips (ColorPhast)

Musthavbeer said:

I,ve been using PH strips (ColorPhast)

Click to expand...

Per Kaiser's info here, test strips are pretty inaccurate. You might consider getting a local water analysis or measuring via another means (at least once, to corroborate your test strip reading).

If you find a more accurate method that's affordable, let me know! This thread along with the recent mash/sparge efficiency thread have been really informative for me, and I'm convinced that I need to start monitoring the pH of my brews.

Yes, the colorphast strips are easier to read than lithmus paper, but seem to show a systematical error for me.

Brewpastor,

So far I strongly believe that PH is the problem why I haven't been able to brew great beers since I moved and started using new water. The brewing water in NC was fairly soft and I didn't have to adjust the water for anything amber and darker. The only really light beer I brewed there, a Hefeweizen, needed some acid malt for PH adjustment. A high boil PH is also known to cause increased and more harsh bitterness. This is also someting I'm struggling with in some of my beers.

Musthavebeer,

My well water is fairly hard and contains elevated levels of arsenic, thats why we got an R/O system for the drinking and cooking water in the house. I also have a water report for both waters. For the latter I convinced my wife that I need to check if the arsenic is gone, but the main reason was to see how the R/O stystem lowers the ion content. Its about 90% lower across the board and brings the water in the range of the Pilsen water. Before I had the necessary salts I just mixed well and R/O water to get brewing water. Though the PH of the mash seemed righ I know now that the alkalinity of the water was still to high. Now, when I build water I use Beersmith to calculate the salt additions. Since I had so much success with the water in NC, I started to use this as a target for many of my beers and may play around with the alkalinity depening on darkness of the beer such that I get the correct mash PH.

But a water PH of 4 seems really low. It is known that distilled and R/O water has a PH lower than 7, but I don't think it can get that low. My R/O water has a PH of 6.0 according to the water report.

Kai

I see. Yes, I have had problems with water as well. My well water is very hard and needs adjusting. More often I use water from a different source, but at times I blend. Your base point is such a good one. Ph is so often over lookied, but can make such a difference. A poll would be interesting on this topic. I will get on it! Hope your dusty problem gets resolved, even if you are making hefe!

I don't think the pH of the water before mashing is all that important - unless you have really hard water. Plain old water has very little buffering capacity and will have little affect on the pH of the mash. The pH of your mash is largely going to be determined by the ingredients you use.

A pH of 5.2 is a pretty good ballpark figure for the pH found in the space between plant cells. The typical pH inside cells is closer to 7.0, but in a grain that space is mostly filled with starch (which does not afect pH). I assume that the pH of the mash is largely determined by the components found outside the cells, which is going to be optimized by the seed for the amylases to function during germination - approximately 5.2. The more grain you use, the greater the buffer capacity will be (the more stable the pH will be).

What I don't know is how the various malting processes affect pH of the grain. I suspect that some of the specialty grains may buffer at non-optimal pH as a result of processing (particularly the high roasts).

Very interesting what you say about malts pjj2ba.

Kaiser, it is my well water that is about 4.

Well, I got my PH meter today and had to play with it. Besides taking the PH of various beers I also tested the ColorPhast strips. To do this I made up buffer solutions by mixing R/O water, the 7.0 and the 4.0 buffer that came with the meter. I measured the PH of these buffers with the PH meter and then with the strips. The strips were read in tungsten light (this actually matters since they look different in fluorescent light). The strips were submerged for at least 5 seconds until the color stopped changing. I then read that they may need to be submerged for 1-10 min and I repeated the 5.3 test with submerging the strip by 5 min and there was no change in the outcome. Here are the results.

test PH meter reading ColorPhast reading error

4.0 . 4.0 (4.01 buffer) ..... 4.0 .... 0.0
4.4 . 4.38 .................. 4.0 ... ~ -0.4
4.7 . 4.70 .................. 4.4 ... ~ -0.3
5.0 . 5.01 .................. 4.7 ... ~ -0.3
5.3 . 5.32 .................. 5.0 ... ~ -0.3
5.5 . 5.50 .................. 5.15 .. ~ -0.3 (read between 5.0 and 5.3)
5.8 . 5.78 .................. 5.5 ... ~ -0.3
6.1 . 6.14 .................. 5.8 ... ~ -0.3
6.5 . 6.47 .................. 6.3 ... ~ -0.2 (read between 6.1 and 6.5)
7.0 . 7.0 (7.01 buffer) ..... 7.0 ... ~ 0.0


I admit, that trying to match colors is not that accurate of a measurement, but these strips are advertised as being precise enough for home brewing. As you can see, there seems to be a systematic error of -0.3 PH units which I already suspected earlier.

After the experiment I checked the calibration of the meter again and it was only off by 0.04 PH units.

I will try to contact the manufacturer of these strips to see if can get an explanation to this. Maybe they tell me that they aren't expected to be that precise and thus unsuitable for home brewing use or maybe I used them wrong.

None of my beers that I brewed past the point where I started to suspect PH is ready for drinking yet. So far I haven't noticed any astringency in these beers, but my palate seems very inconsistent with this. The Dunkel that I'm drinking right now may or may not show this dusty taste when I drink it.

Kai

Oh-no!! now I'm worried. I plan to brew my first AG batch soon and I don't want to mess it up. I have soft water, is the meter and the chemicals something I'm going to need before I do my first brew? Or should I rockit and hope for the best?

67coupe390 said:

Oh-no!! now I'm worried. I plan to brew my first AG batch soon and I don't want to mess it up. I have soft water, is the meter and the chemicals something I'm going to need before I do my first brew? Or should I rockit and hope for the best?

Click to expand...

Coupe,

Don't worry about this if it is your first AG or you don't have off-tastes that can be releated to mash pH. I was fine with just lithmus paper for a long time. The ColorpHast strips aren't cheap ($25 for a pack of 100, though you can cut them into smaller pieces and make them last ) and a pH meter is more than twice that much and requires maintanance. That's why I don't want to make people think that all this is necessary for good beer because it can easily be a waste of money. I simply want to find out why my mash pH was off all the time even though I measured with something that I expected to be sufficiently pecise b/c I spent $25 on it.

And with soft water you should be fine anyway unless you are brewing a very light beer. I also suggest you read up on water chemistry (Palmer's online how-to-brew is pretty good for that. It even features a little normograph that you can use to check the residual alkalinity for the beer that you plan to brew) before you spend any significant money on pH measuring equipment.

Kai

pjj2ba - I don't think not knowing what your ph is before, during or after mashing is sound advice. Hoping the grains take care of the ph is a good way for it to be too high and start causing some off-flavors that all of sudden you can't figure out where they came from. Using (at a minimum) the test strips to at least note it would, at least IMO, serve you better then to ignore it and hope for the best. Unless you know the makeup of your water, and have a recipe developed for it (in order to balance out the ph) then you may be making the wrong style of beer for your water profile.

Example - I have well water, although I don't use it due to a sweet taste that I can't get out of it, and it does affect the taste of my brews. If I were to use it, measure the ph once and then forgeting about might be a huge mistake. The level of the well, of course, goes up and down with rain and the pump sits 260ft in the ground. But I could in no way judge what level my water would be coming from because the supply comes from 2 1500gal tanks. The iron level goes up in the summer because of the lower ground water. When the rain starts, the calcium levels rise. So my water profile would change according to the time of the year, rain amounts, and how "fresh" the water in the tank is. I would have to have it tested frequently and adjust it.

today I racked both the Helles and the Maerzen. Both have been mashed such that the strips read a pH of 5.0 and therefore should not exibit any astringency from the grains. I gave them a taste and to my surprise, the Helles had some astringency and a harsh taste. The Maerzen was very nice and smooth with a low bitterness.

Now I'm thinking that the hops may have played a role in this. The Helles, and many beers before that, used Hallertau Mittelfrueh. The Maerzen was brewed with Tettnanger. This is surprising since the Hallertau is considered a noble hop that should not impart a harsh bitterness. I still have some of the Hallertauer left and run a small batch experiment with it. This time using extract instead of mashing.

Kai

Kaiser said:

today I racked both the Helles and the Maerzen. Both have been mashed such that the strips read a pH of 5.0 and therefore should not exibit any astringency from the grains. I gave them a taste and to my surprise, the Helles had some astringency and a harsh taste. The Maerzen was very nice and smooth with a low bitterness.

Now I'm thinking that the hops may have played a role in this. The Helles, and many beers before that, used Hallertau Mittelfrueh. The Maerzen was brewed with Tettnanger. This is surprising since the Hallertau is considered a noble hop that should not impart a harsh bitterness. I still have some of the Hallertauer left and run a small batch experiment with it. This time using extract instead of mashing.

Kai

Click to expand...

How fresh are your hops? I purchased 3 pounds of hops about 9 months ago and I was wondering what off flavors theyl impart when they go stale. I store them in the freezer in vacuum sealed bags but the E.K. Goldings don't store well. (I found this out after I bought them).

RichBrewer said:

How fresh are your hops?

Click to expand...

I don't know. I bought them 4 months ago and stored them in the freezer since. They must at least be from the 2005 crop. The package doesn't say anything about threir age.

Kai

Finally I have been able to turn out a good beer again. My Alt is now ready for consumption (thanks to Kraeusening I had to wait only 7 days for carbonation). No astringency and no harsh bitterness. This was mashed targeting 5.0 on the strips and used Spalter hops as opposed to the Hallertauer that many of my other troubled batches used. I really like the bitterness that I get from the Spalter.

I'm even thinking about a German single hop experiment where I make 5 small batches with Spalter, Tettnanger, Saaz, Hallertauer and the Hallertauer that I had trouble with. Ferment that with a German lager yeast and bottle with fermentable extract left to give it carbonation and eliminate the secondary.

Kai

I'm thinking about picking up some Tettnanger and possibly some Saaz for the coming year. I've still got plenty of Hersbrucker left, but I'm getting a bit tired of it as well as concerned about its age.

Kaiser said:

Finally I have been able to turn out a good beer again. My Alt is now ready for consumption (thanks to Kraeusening I had to wait only 7 days for carbonation). No astringency and no harsh bitterness. This was mashed targeting 5.0 on the strips and used Spalter hops as opposed to the Hallertauer that many of my other troubled batches used. I really like the bitterness that I get from the Spalter.

I'm even thinking about a German single hop experiment where I make 5 small batches with Spalter, Tettnanger, Saaz, Hallertauer and the Hallertauer that I had trouble with. Ferment that with a German lager yeast and bottle with fermentable extract left to give it carbonation and eliminate the secondary.

Kai

Click to expand...

Yummy.


I do believe you did an excellent job of troubleshooting your problem. My brother has had really poor brewing at his home since he moved in and he is quite discouraged. I am convinced that his problem lies in his water as well. He has brewed at my house using the city water from my tap and has had excellent results. he remarked that he had activity on the ride home and he has never had that happen so quickly at home.

I used to do instrumentation for a living and I will tell you categorically that the accuracy of much instrumentation is highly suspect. Plus or minus 5 % is about standard. That is starting to fall into your margin or error in your case, i.e. strips accuracy vs instrument accuracy. + - 5% X 2 = 10% possible.

Just my 2 cents.

Chers,

knewshound

knewshound said:

That is starting to fall into your margin or error in your case, i.e. strips accuracy vs instrument accuracy. + - 5% X 2 = 10% possible.

Click to expand...

This reminds me. I actually contacted EMD chemicals and here is what I got:

my e-mail said:

EMD team,

I'm a home brewer that started using the ColorpHast 4.0-7.0 strips to
check the PH of the mash. I noticed off flavors to my beer that are commonly associated with mashing pH after I started using these strips and also had to change my brewing water. When I recently got a pH meter to measure the pH during the brewing and fermentation process more precisely I conducted an experiment to check the accuracy of your ColorpHast strips.

For this I created buffer solutions by mixing deionized water, pH 4.01 buffer and pH 7.01 buffer. I used the water to conserve the use of the buffer solutions assuming that the buffering capacity will still be strong
enough for a valid experiment. The strips were submerged for at least 5
seconds. At this point the color stopped changing. I then read that
they may need to be submerged as long as 10min and I repeated the 5.3 test with submerging them for 10min w/o any change in the outcome. The strips were read in tungsten light. Here is what I got:

test - pH meter reading - approx. pH read from the strips

4.0 - 4.0 (4.01 buffer) - 4.0
4.4 - 4.38 - 4.0
4.7 - 4.70 - 4.4
5.0 - 5.01 - 4.7
5.3 - 5.32 - 5.0
5.5 - 5.50 - 5.15 (read between 5.0 and 5.3)
5.8 - 5.78 - 5.5
6.1 - 6.14 - 5.8
6.5 - 6.47 - 6.3 (read between 6.1 and 6.5)
7.0 - 7.0 (7.01 buffer) - 7.0

As you can see, there seems to be a systematic error of about 0.3 over
most of the range. The pH meter was still sufficiently calibrated after the
experiment.

My question now is, what precision can I expect from the ColorpHast
strips? They are widely used in the home brewing community, because they are easier to read than lithmus paper, where a precision of at least 0.2 pH units is needed.

Click to expand...

EMD Chemicals said:

Based on the information below, I am assuming that you are using the
4-7 clorpHast pH parer, part number 9582. The sensitivity of the part
number s 0.2-0.3 pH units. A pH meter will always be more accurate than the pH trips ecause the meter will eliminate any human error in determining
color. Because of the possibility of human error, the strips are consider
semi-quantitative but are more convenient that a pH meter when testing
in the field and pH meter is not easily accessible. If you need further assistance, feel free to contact me.

D. S.
Technical Service Rep
EMD Chemicals
1-800-xxx-xxx
[email protected]

Click to expand...

The conclusion is, that you shouldn't trust these strips to much, they are however better than lithmus paper. And don't get the idea that you need to buy a pH meter now only to see if you have a mash pH problem since you may end up disapointed if this doesn't fix it. pH meters are a ***** to calibrate, but are also a nice tool to have if you actually decide to get one. J. Palmers howtobrew.com has a nice section about residual alkalinity that also features a normograph with which you can get an idea about the water treatment that you may need to brew a certain style of beer.

Kai