Sodium metabisulfite for dissolved oxygen reduction in mash.

[Mekchu]

@mabrungard I'm using Bru'n Water 5.5 for my next beer, an all grain wheat beer, and see that there is a (new to me) feature in the water adjustment page: Sodium metabisulfite addition is calculated for dissolved oxygen reduction in the mash. The water adjustment page recommends doses from 10 ppm to 60 ppm based on how open or close the system is to oxygen. My system is definitely on the upper end of this scale.

I brew with tap water so typically I use Campden tablets (KMS) to eliminate chlorine, etc from my brew water. (And I probably overdoes it by splitting a tablet between mash and sparge water for a 5 gallon batch.)

So my questions are: if 50-60 ppm SMS is added to tap water when I would normally add Campden tab, will it serve both purposes? Will it eliminate chlorine and absorb oxygen? Do KMS tablets have the same oxygen absorption capacity as the suggested SMS addition? In other words has the Campden tablets been doing double duty all along?

I'm guessing that I should not use both Campden tablets for chlorine and SMS as an addition to absorb oxygen. I've tried to read what I can to understand these additions and their functions, but each appears in isolation as if occurring in different universes, rather than the same brew pot.

Any insight you can provide is appreciated.

Oh, and by the way, I found chemistry 101 a huge challenge in college, or is that already evident?

 

[doug293cz]

It's the meta-bisulfite that is responsible for both the chlorine/chloramine and oxygen elimination. The cation (sodium or potassium) doesn't really do anything in these reactions. The only difference is the molecular weights, so the amount needed for xx ppm of meta-bisulfite will be different.

Brew on

 

[Mekchu]

It's the meta-bisulfite that is responsible for both the chlorine/chloramine and oxygen elimination. The cation (sodium or potassium) doesn't really do anything in these reactions. The only difference is the molecular weights, so the amount needed for xx ppm of meta-bisulfite will be different.

Brew on

Thanks! I appreciate your response.

After a week down the water chemistry rabbit hole I'm totally ready to pop out in that direction.

 

[Bilsch]

@mabrungard Sodium metabisulfite addition is calculated for dissolved oxygen reduction in the mash. The water adjustment page recommends doses from 10 ppm to 60 ppm based on how open or close the system is to oxygen. My system is definitely on the upper end of this scale.

That dose range is based on the assumption that all the DO will be removed from the strike water by boiling or yeast DO before beginning the mash. How tight the system is refers to how much oxygen you will pick up from mixing in the grain and from atmospheric diffusion during the mash.

 

[mabrungard]

Chlorine compound neutralization does consume some of the meta, so you do need to account for that. I wouldn’t go overboard with meta additions. It’s not a benefit in all styles. Light lagers are great candidates, but styles like ales don’t seem to benefit in my opinion.

 

[Mekchu]

That dose range is based on the assumption that all the DO will be removed from the strike water by boiling or yeast DO before beginning the mash. How tight the system is refers to how much oxygen you will pick up from mixing in the grain and from atmospheric diffusion during the mash.

Thank you for your response. The software does highly recommend preboiling water. That is something I will have to consider. I'm brewing on my kitchen gas range which takes some time to get 7 gallons to a boil. I could do it the night before to avoid a never ending brew day.

 

[Mekchu]

Chlorine compound neutralization does consume some of the meta, so you do need to account for that. I wouldn’t go overboard with meta additions. It’s not a benefit in all styles. Light lagers are great candidates, but styles like ales don’t seem to benefit in my opinion.

Thank you for your response.

Let me summarize my interpretation of the information above and apply it to my brewing process. Please tell me if I'm off track. As mentioned above I'm brewing ales in my kitchen. Strike water is heated on a gas range and a 10 gal cooler is used for mashing. I transfer strike water from kettle to mash tun using a pitcher and try to avoid too much splashing.

Both KMS and SMS will each remove chlorine/chlorimide and oxygen from municipal tap water. The dose recommended for chlorine elimination should be the followed w/o significant or any additional additions for oxygen absorption.

Last question. If I preboil strike water the night before, would you recommend adding mineral and acid addition prior to boiling or wait until morning after the water has cooled?

Thanks again!

 

[Bilsch]

Strike water is heated on a gas range and a 10 gal cooler is used for mashing. I transfer strike water from kettle to mash tun using a pitcher and try to avoid too much splashing.

Both KMS and SMS will each remove chlorine/chlorimide and oxygen from municipal tap water. The dose recommended for chlorine elimination should be the followed w/o significant or any additional additions for oxygen absorption.

You might look into yeast deoxygenation for your strike water. It’s way easier.. just heat it up, an hour before or the night before, to about 110F then add 2gm/gal of dry baking yeast and the same amount of dextrose. Then when you are ready to brew, raise to your strike temperature, add minerals and meta then proceed as usual.

Since you scoop your water it’s probably best to stay on the high side of the meta dose.
Dont forget to oxygenate your wort before pitching to expend extra sulfites or you’ll end up with a sulfury brew.

 

[Mekchu]

You might look into yeast deoxygenation for your strike water. It’s way easier.. just heat it up, an hour before or the night before, to about 110F then add 2gm/gal of dry baking yeast and the same amount of dextrose. Then when you are ready to brew, raise to your strike temperature, add minerals and meta then proceed as usual.

Since you scoop your water it’s probably best to stay on the high side of the meta dose.
Dont forget to oxygenate your wort before pitching to expend extra sulfites or you’ll end up with a sulfury brew.

Thank you for the suggestion/explanation on using yeast to deoxygenate strike water. To be honest, I did not understand the process the first time you mentioned it so it kind of slipped by me. Yeah, sounds way easier than adding another 7-8 gallon boil to my process.

 

[hamachi]

I wouldn’t go overboard with meta additions. It’s not a benefit in all styles. Light lagers are great candidates, but styles like ales don’t seem to benefit in my opinion.

Could you elaborate a bit on that? Is it because the effects of any hot-side oxidation are less noticeable in ales, or some other reason?

I ask because I make nothing but ales and have been experimenting with some simple hot-side LODO techniques such as pre-boiling and adding a fraction of a gram of K-meta to the strike water. (This is after pre-processing the water the day before with a controlled amount of K-meta to remove chloramines.)

 

[Bilsch]

Could you elaborate a bit on that? Is it because the effects of any hot-side oxidation are less noticeable in ales, or some other reason?

I ask because I make nothing but ales and have been experimenting with some simple hot-side LODO techniques such as pre-boiling and adding a fraction of a gram of K-meta to the strike water. (This is after pre-processing the water the day before with a controlled amount of K-meta to remove chloramines.)

Generally the effects of oxidation on the hot side are covered up nicely by a lot of hops, moderate amount of esters and phenolics, poor attenuation and other faults so it's kind of a situation of why bother.