Weird taste from OxBlox or process?

[rmr9]

I tapped a keg of märzen yesterday and noticed it was a lot more hop forward than I was expecting - particularly from 70 and 40 minute additions amounting to about 25 IBUs (1oz hallertau tradition @70, 1oz Tettnanger @40). It had a very sort of like green-zesty flavor? That’s the only way I can describe it. I’ve noticed it in pretty much all of my lighter colored lagers lately and I’ve found that it seems to maybe correlate with the addition of OxBlox - it could be a coincidence as correlation is not always equivalent to causation. But I digress…

Has anyone noticed odd flavors from using OxBlox? Maybe it’s related to some other aspect of my process or my water chemistry - maybe I’ve come to dislike noble hops? (Less likely since I rave about all the amazing beer I had in Austria/Germany). I dunno…it’s odd and I’m not saying it’s utterly unpleasant but it’s not generally what I’m expecting.

 

[jdauria]

I have used Oxblox and not noticed beers being more hop forward or the green zest flavor. Are you brewing with tap water or using RO or distilled and building up a water profile. I know Noble hops and sulfates don't play well together, do you have high sulfates in your water? Oxblox which contains sodium metabisulfite will add even more sulfate.

I no longer use the product though, as the low oxygen brewing guys on The **************** Discord channel have moved away from adding ascorbic acid, which is also in Oxblox, as they feel it can increase negative reactions in the beer, such as off-flavors or causing darker beers.

 

[rmr9]

I build my water from distilled. I’ve been trying to keep the same water profile as a way to eliminate a variable and to explore ingredients from the same clean slate if that makes sense. I use the profile as follows:

Ca: 53
Mg: 6
SO4: 59
Na: 12
Cl: 86

I add 88% lactic acid into the mash as needed (for example 0.7ml in a helles) and have for some batches acidified in the kettle at beginning of boil (1.9ml lactic) but I didn’t do either of those for the märzen. I’ve gotten that same green-zesty flavor in a helles, a rye lager, 2 Vienna lagers, and this märzen. Using the same water profile (but adding bicarb for pH) I did not experience the flavor in my schwarzbier or Munich dunkel.

At this point I’m really wondering if it’s a water chemistry thing or what. The same thread between all the ones with the taste has been lighter in color and using OxBlox. The hops are generally all either Tettnanger, mittelfrüh, or tradition with additions at 70, 40 and 20 minutes - though in one of the Vienna lagers I FWH with Syrians and finished with an ounce of saaz at 10 minutes. It’s not an altogether unpleasant flavor, but not exactly what I was hoping for and can be a bit distracting

 

[rmr9]

For a more granular view into my process in case it helps here’s the helles for example:

Brewing in a Robobrew/brewzilla

10lbs barke pils, 2lbs barke Vienna
1oz mittelfrüh @70, 0.5oz mittelfrüh @40, 0.5oz mittelfrüh @20 all 3%AA

Mash: hochkurz 145 for 30min, 158 for 45min, 170 for 10min. Mash volume was 6.5 gallons, water profile was used from above with 0.7ml lactic acid, 2g OxBlox.
Sparged with 2 gallons of water with profile from above with 0.6g OxBlox.

In this case I kettle acidified with 1.9ml lactic acid. Boiled 90 minutes, chilled to 49 degrees pitched a decanted 2L starter of Omega Bayern yeast. OG was 1.050, FG was 1.012. Kegged it with gelatin and a pinch (0.3g) of SMB and carbonated at 12psi 38 degrees.

 

[BrewnWKopperKat]

MoreBeer has some additional usage information and commentary on the product page.

eta: I use it at the 0.3g per gal rate for just strike water; and I don't make post mash pH adjustments using lactic / phosphoric acid.

 

[rmr9]

MoreBeer has some additional usage information and commentary on the product page.

eta: I use it at the 0.3g per gal rate for just strike water; and I don't make post mash pH adjustments using lactic / phosphoric acid.

I’ll read the morebeer page and see what’s on there. I use very close to 0.3g per gallon as well. You don’t get any odd flavors in batches using it?

I’ve brewed a couple batches of bitter and Porter in between my lager stream and haven’t noticed anything close to the flavor I’ve seen above. I’ve also never tasted it in a commercial beer before so I wonder now about process. I have a pH meter that I just haven’t opened or used yet. Maybe using that is the best move? I use Bru’n water for my calculations for every batch, maybe I am overlooking something there. I’m planning to brew a German pils in the next couple weeks so I’m really trying to sort this out before then.

 

[rmr9]

I just checked out the Morebeer page, looks like I should stop adding to sparge water and that it can lower mash/final pH by 0.2-0.4.

I guess in the worst case if I was targeting a mash pH of 5.4 it could be as low as 5 and then kettle acidifying could have dropped it to about 4.8. Is that pH low enough to mess with flavors? Still seems fairly close to “accepted normal range”

 

[BrewnWKopperKat]

You don’t get any odd flavors in batches using it?

No, but over the last 9 months, my batches have been APAs and brown ales.

 

[rmr9]

No, but over the last 9 months, my batches have been APAs and brown ales.

Interesting, I’m glad you’re not experiencing the same thing I am!

I think my approach will be to stick to my current water profile, eliminate the OxBlox from my sparge water, drop the OxBlox amount from 0.3g to 0.2g per gallon. Since they say to use 0.2-0.4g per gallon and say it can lower mash pH by 0.2-0.4 I’ll roughly guess that 0.2g will result in 0.2 pH drop (I know it’s not linear)…I’ll target a mash pH of 5.4 that way it will potentially drop to ~5.2 and I’ll ditch the kettle acidification as well?

I’m wondering if the flavor I’m getting is the result of too low pH in the mash/boil?

 

[rmr9]

I’ve also been assuming this water profile which lacks alkalinity is just fine for light colored lagers - am I missing something by not adding any bicarb? My thinking has always been “why add bicarb to just counteract it with lactic acid” but maybe I’m off base (no pun intended)?

 

[rmr9]

I do also run PBW through my robobrew/brewzilla system shortly before brewing to make sure there’s no crud left over that could cause nasty flavors.

 

[Bassman2003]

The road of low oxygen brewing can be sobering at times. It is like running through a gauntlet with your own deficiencies being show to you time after time. It is great for learning and brewing the best beer possible. If that is what you want.

In my experience, the low oxygen process takes away things that you may have been accustomed to with the HIDO process. Mainly the flavor and presence of oxidation. When this is removed what remains is actually your beer. Sometimes, you discover the oxidation is covering up possible flaws in your brewing technique or off flavors etc...

1) Low oxygen brewers only add metabisulfites to the mash. This is where the oxidative reactions occur that can be reduced. The brewer decides how much to add based upon how much LODO you actually want and how "tight" your system is. If you have no other oxygen mitigation in your setup, naturally you would start with more metabisulfites.

2) Do you do YOS to your brewing water? 1-2 grams of baker's yeast per gallon and 1-2 grams of sugar per gallon left 30 minutes to overnight.

3) Low Oxygen brewing will make hops stand out in comparison to HIDO brewing because of the removal of oxidation related flavors. To further the hop presence, if you ferment under pressure, the hops stand out even more. If you can get the image that a low oxygen wort fermented under 1,2 or 3 BAR you get commercial style IPA because the big boys' with their large conicals have 3 BAR+ of hydrostatic pressure to deal with. This is why major name breweries have such a distinct hop presence. You can too with LODO + pressure.

4) Are you upping your pre-fermentation oxygenating? Sulfites need to be "expended" before you move on to fermentation. Meaning you need to introduce enough oxygen to get rid of the remaining metabisulfites to bring you back to "even". Yeast does not love sulfites and can create off flavors if they are mixed. So if you can not measure the DO, then just over-oxygenate. How much O2? - Do 2 minutes at .5 LPM, wait a bit then to 2-4 minutes more at .5 LPM and see how your fermentation goes. If you are using dry yeast then just do the first 2 minutes.

5) The flavors you describe might be a Hint of infection that was covered up by oxidation. I would examine your process and try to improve upon sanitation etc... Like I said, you will be better for it but it will bruise your ego...

The Ox blox is probably fine. If you want to use what the LODO people are using, just get sodium metabisulfite along with Brewtan-B. Add the SMB at 1-2 grams per 5 gallon batch and 1/2 teaspoon Brewtan in the mash and 1/4 teaspoon with 15 minutes left in the boil (before the Whirlfloc at 5 minutes).

Keep at at and if you want to find out what is behind the curtain, visit the Discord!

 

[rmr9]

The road of low oxygen brewing can be sobering at times. It is like running through a gauntlet with your own deficiencies being show to you time after time. It is great for learning and brewing the best beer possible. If that is what you want.

In my experience, the low oxygen process takes away things that you may have been accustomed to with the HIDO process. Mainly the flavor and presence of oxidation. When this is removed what remains is actually your beer. Sometimes, you discover the oxidation is covering up possible flaws in your brewing technique or off flavors etc...

1) Low oxygen brewers only add metabisulfites to the mash. This is where the oxidative reactions occur that can be reduced. The brewer decides how much to add based upon how much LODO you actually want and how "tight" your system is. If you have no other oxygen mitigation in your setup, naturally you would start with more metabisulfites.

2) Do you do YOS to your brewing water? 1-2 grams of baker's yeast per gallon and 1-2 grams of sugar per gallon left 30 minutes to overnight.

3) Low Oxygen brewing will make hops stand out in comparison to HIDO brewing because of the removal of oxidation related flavors. To further the hop presence, if you ferment under pressure, the hops stand out even more. If you can get the image that a low oxygen wort fermented under 1,2 or 3 BAR you get commercial style IPA because the big boys' with their large conicals have 3 BAR+ of hydrostatic pressure to deal with. This is why major name breweries have such a distinct hop presence. You can too with LODO + pressure.

4) Are you upping your pre-fermentation oxygenating? Sulfites need to be "expended" before you move on to fermentation. Meaning you need to introduce enough oxygen to get rid of the remaining metabisulfites to bring you back to "even". Yeast does not love sulfites and can create off flavors if they are mixed. So if you can not measure the DO, then just over-oxygenate. How much O2? - Do 2 minutes at .5 LPM, wait a bit then to 2-4 minutes more at .5 LPM and see how your fermentation goes. If you are using dry yeast then just do the first 2 minutes.

5) The flavors you describe might be a Hint of infection that was covered up by oxidation. I would examine your process and try to improve upon sanitation etc... Like I said, you will be better for it but it will bruise your ego...

The Ox blox is probably fine. If you want to use what the LODO people are using, just get sodium metabisulfite along with Brewtan-B. Add the SMB at 1-2 grams per 5 gallon batch and 1/2 teaspoon Brewtan in the mash and 1/4 teaspoon with 15 minutes left in the boil (before the Whirlfloc at 5 minutes).

Keep at at and if you want to find out what is behind the curtain, visit the Discord!

Thanks for the in depth reply! I’m not a LODO brewer but I would call myself “LODO-curious”. I’m unsure how to implement most of the processes on my AiO setup but figured adding OxBlox maybe wouldn’t hurt? Anyhow here are some answers to your questions:

1) no other mitigation steps - is LODO all or nothing or can little aspects help?

2) not yet but I could set the robobrew to temp the night before and add bread yeast and sugar but again as in 1 is it worth it without going all the way?

3) my issue is less about getting hop expression and more that they’re too forward in the beers with a green-zesty (grassy?) flavor. Maybe I don’t like noble hops - but in commercial beers I love them. Bad Tettnanger/Mittelfrüh I was using?

4) yep, I oxygenate for 90 seconds pure O2. Don’t have a flow meter but fermentation kicks off quick and I’m usually at FG within 2 weeks.

5) I’m all for upping my sanitation game! I PBW everything after use, hit everything with starsan as well. I could afford to scour the ball valve more vigorously on my robobrew. I would be inclined to agree on potential contamination but this off note only really comes out with lighter lagers, haven’t had it in dark lagers, porter or bitters I’ve made in between the lighter lager batches. Only thing I haven’t sanitized is my CO2 line - maybe here is the problem?

It’s not a horrible off flavor, I can drink and enjoy the beer, it’s just not what I’m wanting, and kinda has become a “standard flavor” in all my light colored lagers and I’d prefer to not have it haha

 

[Bassman2003]

1) Contrary to the first thinking, no, LODO is not all or nothing. Every little bit helps. The largest steps are YOS treatment, sulfites and system process changes. Lowering or raising a bag is difficult. If you have to, do it slowly.

2) YOS is very easy and very impactful. It takes all of the oxygen away from your brewing water. That is a huge step.

3) I can't know what you are tasting, but try less IBUs. I think it is telling that this is only showing up in pale beers.

4) Double that at least.

5) There are a lot more places to hide in the darker beers. Keep at it but really take a hard look at all contact points for sanitation. Even the serving lines. Also, try some different hops or a different supplier.

Here is a video I made about the impact of low oxygen brewing -

 

[rmr9]

1) Contrary to the first thinking, no, LODO is not all or nothing. Every little bit helps. The largest steps are YOS treatment, sulfites and system process changes. Lowering or raising a bag is difficult. If you have to, do it slowly.

2) YOS is very easy and very impactful. It takes all of the oxygen away from your brewing water. That is a huge step.

3) I can't know what you are tasting, but try less IBUs. I think it is telling that this is only showing up in pale beers.

4) Double that at least.

5) There are a lot more places to hide in the darker beers. Keep at it but really take a hard look at all contact points for sanitation. Even the serving lines. Also, try some different hops or a different supplier.

Here is a video I made about the impact of low oxygen brewing -

Good points, maybe I’ll stick to my OxBlox (.2g per gallon in just the mash), give YOS a try as well. I was considering using the Tettnanger I have (same supplier/purchased at same time as the ones from the märzen) but maybe I’ll cut those and go with straight perle.

The IBUs weren’t terribly high - calculated to maybe a shade under 25 for the märzen. Maybe the key is to err on the lower bitterness side for a style instead of higher end as you say.

It never hurt anyone to give a really deep clean of their equipment so I’ll keep doing and redoing that bit.

I’ll probably deal with mash pH as above, even though it’s a lot of variables to change for a batch.

 

[rmr9]

Also I’ll be watching that video tonight! Thanks for the link.

 

[Miraculix]

The road of low oxygen brewing can be sobering at times. It is like running through a gauntlet with your own deficiencies being show to you time after time. It is great for learning and brewing the best beer possible. If that is what you want.

In my experience, the low oxygen process takes away things that you may have been accustomed to with the HIDO process. Mainly the flavor and presence of oxidation. When this is removed what remains is actually your beer. Sometimes, you discover the oxidation is covering up possible flaws in your brewing technique or off flavors etc...

1) Low oxygen brewers only add metabisulfites to the mash. This is where the oxidative reactions occur that can be reduced. The brewer decides how much to add based upon how much LODO you actually want and how "tight" your system is. If you have no other oxygen mitigation in your setup, naturally you would start with more metabisulfites.

2) Do you do YOS to your brewing water? 1-2 grams of baker's yeast per gallon and 1-2 grams of sugar per gallon left 30 minutes to overnight.

3) Low Oxygen brewing will make hops stand out in comparison to HIDO brewing because of the removal of oxidation related flavors. To further the hop presence, if you ferment under pressure, the hops stand out even more. If you can get the image that a low oxygen wort fermented under 1,2 or 3 BAR you get commercial style IPA because the big boys' with their large conicals have 3 BAR+ of hydrostatic pressure to deal with. This is why major name breweries have such a distinct hop presence. You can too with LODO + pressure.

4) Are you upping your pre-fermentation oxygenating? Sulfites need to be "expended" before you move on to fermentation. Meaning you need to introduce enough oxygen to get rid of the remaining metabisulfites to bring you back to "even". Yeast does not love sulfites and can create off flavors if they are mixed. So if you can not measure the DO, then just over-oxygenate. How much O2? - Do 2 minutes at .5 LPM, wait a bit then to 2-4 minutes more at .5 LPM and see how your fermentation goes. If you are using dry yeast then just do the first 2 minutes.

5) The flavors you describe might be a Hint of infection that was covered up by oxidation. I would examine your process and try to improve upon sanitation etc... Like I said, you will be better for it but it will bruise your ego...

The Ox blox is probably fine. If you want to use what the LODO people are using, just get sodium metabisulfite along with Brewtan-B. Add the SMB at 1-2 grams per 5 gallon batch and 1/2 teaspoon Brewtan in the mash and 1/4 teaspoon with 15 minutes left in the boil (before the Whirlfloc at 5 minutes).

Keep at at and if you want to find out what is behind the curtain, visit the Discord!

How would you approach metabisulfite dosing for the mash if you wouldn't oxygenate at all?

How can one get an idea of the dose that's big enough to get most of the oxygen but small enough so that it's gone when the yeast is being pitched?

 

[rmr9]

I’m wondering if the act of sparging would introduce oxygen to “soak up” some of the metabisulfite and then oxygenating deals with much of the rest while still leaving oxygen for the yeast?

 

[Bassman2003]

How would you approach metabisulfite dosing for the mash if you wouldn't oxygenate at all?

How can one get an idea of the dose that's big enough to get most of the oxygen but small enough so that it's gone when the yeast is being pitched?

That is difficult without a DO meter. It takes some brews on your system to see how much the overall process adds oxygen from start to finish. The general approach has been to add a lot of oxygen at the end for the yeast to soak up which also covers expending the SMB. Over time, you dial things in and end up using less SMB and "right size" the amount to your system.

In doing this, the community learned just how important oxygen is to the yeast. By adding a lot more oxygen at the end, it was discovered how much better the yeast acted. This really comes into play with pressure fermentation at the homebrew scale. (we have to use CO2 based pressure instead of hydrostatic pressure from large tanks). Since CO2 is toxic to yeast, especially after 15 psi, massive oxygen (20+ ppm DO) is needed for a healthy fermentation at normal style temps.

 

[Miraculix]

That is difficult without a DO meter. It takes some brews on your system to see how much the overall process adds oxygen from start to finish. The general approach has been to add a lot of oxygen at the end for the yeast to soak up which also covers expending the SMB. Over time, you dial things in and end up using less SMB and "right size" the amount to your system.

In doing this, the community learned just how important oxygen is to the yeast. By adding a lot more oxygen at the end, it was discovered how much better the yeast acted. This really comes into play with pressure fermentation at the homebrew scale. (we have to use CO2 based pressure instead of hydrostatic pressure from large tanks). Since CO2 is toxic to yeast, especially after 15 psi, massive oxygen (20+ ppm DO) is needed for a healthy fermentation at normal style temps.

Hmmm... That's what I thought you would say, makes sense. I'm not going to invest in oxygen I think and a DO meter is probably also quite expensive, isn't it?

I'm doing biab with YOS, without underletting, with the occasional stir at the beginning plus boiling water additions for temperature steps. This obviously involves additional stirring to even out the temperature. No pressure rig and also not planning to get this stuff. I'm also squeezing the bag and splashing a bit during the process. I intentionally keep things as simple as possible here. One pot, one fermenter.

So there's definitely some o2 getting into the mash one way or another. I might start experimenting with something around 1.2g mbs per 5 gallon. If there's no downside, I might increase it in 0.2g steps.

 

[Bassman2003]

The group has learned over the years that 'all or nothing' was an early viewpoint that was not true. So things still show improvement along with steps taken. If you have a simple system (which is fine) you just add more sulfites to account for the increased oxygen exposure. The original amount of sulfites were 100+ ppm. Now most of the group is down around 25-35 ppm. I add 1 to 1.2 grams of sodium metabisulfite to 8.25 gallons of strike water (full volume mash) for all of the batches. So not a lot in the grand scheme of things. But my system has been optimized to some extent. But you do what you can or want to do following the beer quality.

 

[Miraculix]

The group has learned over the years that 'all or nothing' was an early viewpoint that was not true. So things still show improvement along with steps taken. If you have a simple system (which is fine) you just add more sulfites to account for the increased oxygen exposure. The original amount of sulfites were 100+ ppm. Now most of the group is down around 25-35 ppm. I add 1 to 1.2 grams of sodium metabisulfite to 8.25 gallons of strike water (full volume mash) for all of the batches. So not a lot in the grand scheme of things. But my system has been optimized to some extent. But you do what you can or want to do following the beer quality.

Thanks, I am very glad on many levels to read this.

I am not sure if I should jump on the brewtan b train as well or not. I think that I might have diffilculties of sourcing this in Germany anyway, so I would need to find a suitable replacement.

But it is probably anyway not the best idea to change many variables at once.

 

[Bassman2003]

Brewtan is amazing for making clear wort. It clears the mash going into the kettle and helps clear the kettle going into the fermenter.

There are limits as in BIAB will never be as good as a 3v system no matter how much sulfites you throw at it. But there will be improvements.

 

[rmr9]

Brewtan is amazing for making clear wort. It clears the mash going into the kettle and helps clear the kettle going into the fermenter.

There are limits as in BIAB will never be as good as a 3v system no matter how much sulfites you throw at it. But there will be improvements.

Is there an easy to way account for water chemistry changes with some of the LODO mash additives? I know OxBlox can drop pH 0.2-0.4 but that’s a fairly decent range given optimal mash pH. Do sulfites impact flavor like sulfates do?

 

[Bassman2003]

YOS drops the pH some. I am not aware of sodium metabisulfite alone dropping pH. Sulfites turn into sulfates when you "expend" them. So that is something keep track of if you put a lot of sulfites in, you will get more sulfates. Flavor thresholds are not met at our levels of usage. The flavor impact is the lack of oxidation which is a strong flavor in beer.

 

[rmr9]

YOS drops the pH some. I am not aware of sodium metabisulfite alone dropping pH. Sulfites turn into sulfates when you "expend" them. So that is something keep track of if you put a lot of sulfites in, you will get more sulfates. Flavor thresholds are not met at our levels of usage. The flavor impact is the lack of oxidation which is a strong flavor in beer.

I think I mentally repressed the sulfite>sulfate reaction from general chemistry!

Does YOS impact mash pH or just the pH of the strike water (does it matter either way?)

I think I have a good path forward with my pils, going to try YOS, cut down the OxBlox to just the mash, drop this lot of Tettnanger and go with straight perle for my hopping. They’re only 5.2% AA so I’m thinking 0.5oz at FW, 1oz at 70min, 0.25oz at 40min and 20min. See if the odd flavor is still around after that.

 

[BrewnWKopperKat]

“LODO-curious

In the spirit of curiosity, have you seen this (link to topic at HomeBrewTalk)?

 

[rmr9]

In the spirit of curiosity, have you seen this (link to topic at HomeBrewTalk)?

I sure have, read it in short passing but maybe I’ll take another closer look! At the bottom of the page here it’s the top of “similar threads”

 

[Bassman2003]

I think I mentally repressed the sulfite>sulfate reaction from general chemistry!

Does YOS impact mash pH or just the pH of the strike water (does it matter either way?)

I think I have a good path forward with my pils, going to try YOS, cut down the OxBlox to just the mash, drop this lot of Tettnanger and go with straight perle for my hopping. They’re only 5.2% AA so I’m thinking 0.5oz at FW, 1oz at 70min, 0.25oz at 40min and 20min. See if the odd flavor is still around after that.

Sounds like a good plan. YOS has a minor impact on mash pH to the down side.

 

[Miraculix]

Sounds like a good plan. YOS has a minor impact on mash pH to the down side.

Are you aware of somebody with a DO meter who checked the impact of mash hopping on DO and the results?