Please turn on javascript in your browser to play chess.
Science Forum

Science Forum

  1. 11 Aug '17 09:25 / 1 edit
    As a master brewer, part alchemist and part great artist charged with turning malted grain into crisp liquid gold we have come to understand that oxygen is mostly detrimental to the brewing process. Oxygen causes instability and can result in the polymerisation of certain elements, flavanoids by way of example. When flavanoids oxidise they produce oligomeric polyphenols which are able to crosslink protein molecules resulting in instability, haze etc To combat this we try to reduce dissolved oxygen levels as much as possible. We pre boil water and use sodium metabisulphite to act as an active oxygen scavenging agent. This brings me to my question.

    It is my understanding that sodium metabisulphite adds sodium (Na) and sulphate (So4) to the liquor. Can anyone explain if this is the case or not and in what ratios.

    Many thanks Robbie
  2. 11 Aug '17 12:32
    Originally posted by @robbie-carrobie
    As a master brewer, part alchemist and part great artist charged with turning malted grain into crisp liquid gold we have come to understand that oxygen is mostly detrimental to the brewing process. Oxygen causes instability and can result in the polymerisation of certain elements, flavanoids by way of example. When flavanoids oxidise they produce ...[text shortened]... liquor. Can anyone explain if this is the case or not and in what ratios.

    Many thanks Robbie
    From my research, the sodium metabisulphite is used to get rid of the chlorine, specifically chloramine which boiling doesn't remove well.

    https://byo.com/malt/item/902-it-was-suggested-that-adding-sodium-metabisulfite-to-the-water-would-clear-the-chloramine
  3. Standard member sonhouse
    Fast and Curious
    11 Aug '17 13:28
    Originally posted by @robbie-carrobie
    As a master brewer, part alchemist and part great artist charged with turning malted grain into crisp liquid gold we have come to understand that oxygen is mostly detrimental to the brewing process. Oxygen causes instability and can result in the polymerisation of certain elements, flavanoids by way of example. When flavanoids oxidise they produce ...[text shortened]... liquor. Can anyone explain if this is the case or not and in what ratios.

    Many thanks Robbie
    I was thinking about electroysis where electricity and electrodes produce H2 and O2. So I was thinking about a means of driving that backwards. What about introducing HO to the water. Seems it would look for O2 and turing the mix to water, H2O. Not sure how to do that but it's a thought.
  4. 11 Aug '17 14:35
    Originally posted by @eladar
    From my research, the sodium metabisulphite is used to get rid of the chlorine, specifically chloramine which boiling doesn't remove well.

    https://byo.com/malt/item/902-it-was-suggested-that-adding-sodium-metabisulfite-to-the-water-would-clear-the-chloramine
    yes this is also a valid application, chlorine can have a negative effect on taste later on down the line where it is reported to sometimes contribute to a 'medicinal' taste.
  5. 11 Aug '17 14:37 / 1 edit
    Originally posted by @sonhouse
    I was thinking about electroysis where electricity and electrodes produce H2 and O2. So I was thinking about a means of driving that backwards. What about introducing HO to the water. Seems it would look for O2 and turing the mix to water, H2O. Not sure how to do that but it's a thought.
    I am not actually very sure of the differences between sulphates and sulphites. Does sodium metabisulphite actually add sulphates to water? if so in what ratio. eg. 6 parts sodium, 20 parts sulfate. Something like that.
  6. Standard member sonhouse
    Fast and Curious
    11 Aug '17 16:30 / 1 edit
    Originally posted by @robbie-carrobie
    I am not actually very sure of the differences between sulphates and sulphites. Does sodium metabisulphite actually add sulphates to water? if so in what ratio. eg. 6 parts sodium, 20 parts sulfate. Something like that.
    http://www.foodsmatter.com/allergy_intolerance/sulphites/articles/sulphates_sulphites.html

    https://www.quora.com/How-does-sulfate-and-sulfite-differ
  7. 11 Aug '17 17:23
    You might like this page

    http://www.winning-homebrew.com/low-oxygen-brewing.html