O2 rates and lack of character?

I am struggling lately with a lack of character in my beers. I am starting to think that it is either a pitch issue or a O2 issue. My last beer was a Northern Brown ale based on the Brewing Classic Styles recipe. It started at 1.050 and finished at 1.014. Fermented with wlp007 after a 155 degree mash. My water is very soft, so I bring the calcium up to 100ppm and the chloride and sulfate to roughly 130 and 90 respectively. Mash pH was 5.5 and I acidified the boil to 5.2 using lactic. the pH measurements are taken after the sample is cooled to 25C degrees using an omega meter (http://www.omega.com/pptst/PHH-7000.html). All my brews are 11.8 gallon. I then pitch either a harvested slurry or new gen smack pack using mr. malty. I have been aerating using pure O2 with a medical regulator set to 0.5L/minute for 2-2.5 minutes through a 0.5 micron stone. I have noticed that when I re-harvest I am getting more yeast recovered than I think I should. And most importantly I am having a hard time nailing my bitterness (usually low, excess yeast?) and the beer always lacks malt character. And what malt flavor there is finishes very early. There is also a slight sour like note that is not infection related. I am going to start counting my pitch and high krausen counts next, but does this 02 rate or problem in general seem familiar to anyone?

I would adjust the mash pH not the boil pH; but, 5.5 is within range.

I add O2 based off gravity. Some stuff I have read says that higher gravity beers require more O2, so a session beer is fine at 6-8ppm (doable with shaking) and a high grav 1.080 plus requiring 16ppm or more further, higher gravity wort makes it harder to dissolve O2. I ballpark 30 seconds for session beers, 45 for standard gravity, 1 minute for high gravity on a 5 gallon batch.

Many argue that you cannot over oxygenate wort, so even at the theoretical maximum of around 43ppm you would be fine. However, I don't know if I am in that camp as the krebs cycle tells us that in an oxygenated environment less alcohol is produced...a little due to the crabtree effect yes, but not nearly as much as in an anaerobic environment. So, I would expect that if a wort were overly oxygenated one could see an excess of yeast production and diminished ester production. You should be around 40million cells/ml during the height of fermentation so if you have the ability to count cells and you are getting far higher numbers than you have too much growth.

As far as lacking in malt character or bitterness, that is really hard to assess. This really may be a matter of learning your system, you may simply need to adjust your hop additions to get the character you want and adjust your mash temps and grain builds to get the malt profile you seek.

beerbeer95648 said:

I am struggling lately with a lack of character in my beers. I am starting to think that it is either a pitch issue or a O2 issue. My last beer was a Northern Brown ale based on the Brewing Classic Styles recipe. It started at 1.050 and finished at 1.014. Fermented with wlp007 after a 155 degree mash. My water is very soft, so I bring the calcium up to 100ppm and the chloride and sulfate to roughly 130 and 90 respectively. Mash pH was 5.5 and I acidified the boil to 5.2 using lactic. the pH measurements are taken after the sample is cooled to 25C degrees using an omega meter (http://www.omega.com/pptst/PHH-7000.html). All my brews are 11.8 gallon. I then pitch either a harvested slurry or new gen smack pack using mr. malty. I have been aerating using pure O2 with a medical regulator set to 0.5L/minute for 2-2.5 minutes through a 0.5 micron stone. I have noticed that when I re-harvest I am getting more yeast recovered than I think I should. And most importantly I am having a hard time nailing my bitterness (usually low, excess yeast?) and the beer always lacks malt character. And what malt flavor there is finishes very early. There is also a slight sour like note that is not infection related. I am going to start counting my pitch and high krausen counts next, but does this 02 rate or problem in general seem familiar to anyone?

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I have noticed with english yeast especially, that over pitching and to much o2 will make them go very neutral, they seem to have less body as well.

nstnate said:

I have noticed with english yeast especially, that over pitching and to much o2 will make them go very neutral, they seem to have less body as well.

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This is my first batch with 007. Everything else has been 002. And I had been surprised how neutral those were with this current issue. I wonder how dissolved O2 differs between 5gal and 10gal batches when the same O2 rate and times are applied? I had doubled what others were doing with 5gal batches. I wonder if that is a mistake.

How much lactic are you having to add? It will produce a sour or tart taste at high enough levels. You might try 1/4 pound of acid malt in your grain bill, that seems to work well for me using RO water with low SRM beers. That being said, if my mash pH is 5.5 I leave it alone.

helibrewer said:

How much lactic are you having to add? It will produce a sour or tart taste at high enough levels. You might try 1/4 pound of acid malt in your grain bill, that seems to work well for me using RO water with low SRM beers. That being said, if my mash pH is 5.5 I leave it alone.

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In the mash I may have to add 1 ml. For a 14 gal pre-boil it is usually 1-2 ml.

Keep the chloride level under 100 ppm- you can go much lower, but 100 ppm should be about the max. For an English brown, you can keep the sulfate low as well. This could be where the lack of bitterness comes from- too much chloride.

You don't have to acidify the boil- the boil itself and the hops additions will lower the pH in the boil.

The amount of 02 should be ok, but you could try using the pure 02 for only 30 seconds to see if that makes a difference. I don't think it's easy to overaerate, but it's possible in theory I guess.

Yooper said:

Keep the chloride level under 100 ppm- you can go much lower, but 100 ppm should be about the max. For an English brown, you can keep the sulfate low as well. This could be where the lack of bitterness comes from- too much chloride.

You don't have to acidify the boil- the boil itself and the hops additions will lower the pH in the boil.

The amount of 02 should be ok, but you could try using the pure 02 for only 30 seconds to see if that makes a difference. I don't think it's easy to overaerate, but it's possible in theory I guess.

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I would add that it may not over oxygenated for 2 plus minutes, but just to much for that strain.

Yooper said:

Keep the chloride level under 100 ppm- you can go much lower, but 100 ppm should be about the max. For an English brown, you can keep the sulfate low as well. This could be where the lack of bitterness comes from- too much chloride.

You don't have to acidify the boil- the boil itself and the hops additions will lower the pH in the boil.

The amount of 02 should be ok, but you could try using the pure 02 for only 30 seconds to see if that makes a difference. I don't think it's easy to overaerate, but it's possible in theory I guess.

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Well I am going to re-brew this brown in a week or two. I am going to drop the oxygen to 1 min and see what happens. I have seen over oxygenation in a professional setting a few times. Once at a large Pacific Northwest brewery, and at a micro. In the first case it showed up as excess cell growth which would then cause high diacetyl levels and large tank bottoms. This was with a multi million dollar brewhouse and full lab. We didnt catch it until the high krausen cell counts reached 100 million. In the micro it would give the beer a different (harder to describe, almost 1 dimensional) character that was not that far off what I am dealing with, but like I said it was different.

Pushing the chloride up was an attempt to bring out the malt due to frustration with this issue. But I did add a bit more in a glass to see what it would do, and it did seem to mute things. I am getting agitated at this issue for sure.

beerbeer95648 said:

Pushing the chloride up was an attempt to bring out the malt due to frustration with this issue. But I did add a bit more in a glass to see what it would do, and it did seem to mute things. I am getting agitated at this issue for sure.

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Yeah, chloride is great at providing a sort of sweet rounded mouthfeel. I'd try to keep the chloride lower, and the sulfate as well for a brown ale.

Thanks Yooper. I have never had to deal with water chemistry in the past, but after I moved I am now dealing with very soft water like I said. In fact if you feel like looking and chiming in here is my report:

http://www.eid.org/modules/showdocument.aspx?documentid=3538

The funny thing to me is for fun I brewed a stout without any salt additions and it didnt seem to drop lower that 5.3 in the mash with a 1.25/qt ratio?

beerbeer95648 said:

Thanks Yooper. I have never had to deal with water chemistry in the past, but after I moved I am now dealing with very soft water like I said. In fact if you feel like looking and chiming in here is my report:

http://www.eid.org/modules/showdocument.aspx?documentid=3538

The funny thing to me is for fun I brewed a stout without any salt additions and it didnt seem to drop lower that 5.3 in the mash with a 1.25/qt ratio?

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I'm definitely no water expert! If you really want to learn about water chemistry, head over to the Brew Science forum area where the smart people hang out. We have a couple of water chemistry experts and others who can be of far more help than I can, just because they have the knowledge and experience.

Overall, the water looks great. You can definitely work with that with a minimum of fuss for all beer styles.

Something as simple as the "Water Primer" can be useful for this water, since it seems to be very close to RO water.

Good idea Yooper. Once I figure out this issue with the bland malt character, I am going to play a bit more with this water. Cheers everyone.