Methanol

Discussion in 'Chemistry' started by Beer w/Straw, Dec 24, 2019.

  1. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    5,251
    Wine yeast is for ethanol, is methanol from bacteria contamination?

    I'm looking forward to making wine than I caught a look at this: https://www.cnn.com/2019/12/24/asia/lambanog-poisoning-philippines-intl-hnk-scli/index.html

    The only part that I wouldn't have any control over is the secondary fermentation where the yeast would just sit there for a long time, eating sugar and burping out CO2. Aside from normal sanitation I plan to use a pressure cooker for 5 min at 120C , 15 PSI (before adding the yeast of course) and aiming for 17% ABV (I also have carbonation tablets later on and primary fermentation will have the yeast swimming at 80-82F for two days).

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    I'm going to post this also at a hombrew site, yet I don't know if I really need worry about methanol.
     
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  3. origin In a democracy you deserve the leaders you elect. Valued Senior Member

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    You do not need to worry about methanol.
    I have made many wines and beer batches. If the batch is contaminated with wild yeast or bacteria, all that will happen is that you will get a crappy tasting brew, it won't hurt you.
     
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  5. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    Anyway, one thing that looked promising once I blended 1.6 L of peach halves in juice concentrate, filtered water and copious amounts of sugar it was too thick to get a hydrometer reading but once going through the pressure cooker it seemed to squeeze all the juice out of the remaining fruit.

    Also, last time I visited a homebrewing site I got called a troll and felt awkward as if were encroaching on an all buys club
     
    Last edited: Dec 24, 2019
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  7. exchemist Valued Senior Member

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    I don't think you need to worry unless you are going to distill it, which can concentrate any trace methanol that may have been generated, in the first part of the distillate to come off.

    Some advice here: https://www.howtohomebrewbeers.com/2018/03/methanol-brewing-risks.html

    It seems the issue is pectin being broken down by enzymes that split esters (esterases) that some bacteria, fungi and yeasts can possess. It does seem to be true that there is more pectin in grape juice that in beer wort. However the sources I can find suggest that significant amounts of methanol (i.e. enough to cause a health problem) are not produced in normal fermentation.

    However the boiling point of methanol is lower than that of ethanol, so if you distill wine, you will get the methanol off first. It would therefore be important to discard the first cut that comes over before the boiling point of ethanol is reached.
     
  8. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    I also plan to use
    And it's pretty much a guess as to what temp to set it at.
     
  9. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    Does that mean I technically can boil off any methonal and leave the ethanol content alone?
     
  10. exchemist Valued Senior Member

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    8,797
    If you mean attempting to boil wine, then no, because heating wine will ruin its flavour - and also ethanol will also start to come off as soon as its vapour pressure becomes appreciable: it does not only come off once its boiling point is reached.

    If you are distilling, you will lose a bit of ethanol along with the methanol at the front end, which is unavoidable and necessary as you must get rid of the low-boiling impurities.

    Honestly if you are making wine from grapes and following the normal rules, I think you can forget about methanol as a risk. If you are making it from other fruit with a lot of pectin, it might be a good idea to consult sources that deal with the making of wine from the fruit in question, just in case.
     
  11. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    This is a total guess, and hey, I get to experiment.

    If the heat and pressure from the pressure cooker separate pectin from fibers of the fruit a pectic enzyme could more easily quell a production of methanol.

    Peach wine is a lot more weird than I thought.

    https://blog.eckraus.com/dealing-with-a-cloudy-peach-wine

    https://sciencing.com/test-alcohol-methanol-8714279.html
     
  12. Seattle Valued Senior Member

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    5,378
    There is a better method (cheaper and tastier) but it involves going to the grocery store.
     
  13. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    Challenge accepted.

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  14. exchemist Valued Senior Member

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    8,797
    Ah, now this is interesting. Acidified dichromate is an oxidising agent that oxidises alcohols to the corresponding aldehyde. (I could not remember the details so had to look it up, but at least my background enabled me to understand it once I had found it!)

    Anyway, if only ethyl alcohol is present you get acetaldehyde, which has an ether-like smell. However if methanol is present you get formaldehyde........which is pungent and irritating.

    It is important to have an excess of alcohol compared to the oxidising agent, to avoid it going on to oxidise the aldehyde further, to the corresponding acid, either acetic (smell like vinegar and irritates the eyes) or formic (which is is also very irritating).

    More details here: https://www.chemguide.co.uk/organicprops/alcohols/oxidation.html

    Thanks, BwS, it's been a while since we had any decent chemistry on this site.

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  15. RainbowSingularity Valued Senior Member

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    Toxic coconut wine kills at least 11 people during Christmas celebrations in the Philippines
    https://edition.cnn.com/2019/12/24/asia/lambanog-poisoning-philippines-intl-hnk-scli/index.html

    By Michelle Lim, CNN

    Lambanog, is distilled from coconut sap and has an alcohol content of 40% to 45% by volume.
    Updated 0507 GMT (1307 HKT) December 24, 2019


    im not versed in alcohol distilment beer brewing or chemistry
    what i do have is an old mental note something about sap being potentially highly toxic for some reason
    fatal levels of tannins or something ?

    toxicology thoughts long term terminal injury([methanol]alcohol poisoning)
    liver failure ?
    kidney failure ?
    renal failure ?
    semi-perminent nervous system damage ?

    probably harder to track in countrys with shorter life expectancy's and higher mortality rates.
     
    Last edited: Dec 25, 2019
  16. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    That question is kinda' hard. A temperature range from room to 100C. After 100C to 120C the cooker would lock with like more atmospheric pressure than that of sea level.

    :EDIT:

    Also, an air lock can fit snugly atop the cooker but I'm not going to count it as a pressure valve.
     
    Last edited: Dec 25, 2019
  17. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    5,251
    :BUMP:

    Looking for a small fermenter to sous vide the yeast in an instant pot in need specific diameter specs. I thought I had found one but got struck with this daft warning: "WARNING: This product can expose you to chemicals including Tetrafluoroethylene, which are known to the State of California to cause cancer. Prop 65 Warning".

    The heck does tetrafluoroethylene have to do with an amber glass 4L bottle?

    https://www.calpaclab.com/4-liter-amber-glass-bottle-black-ptfe-lined-cap/ec-38gl
     
  18. billvon Valued Senior Member

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    16,750
    No.

    Methanol is formed when pectin is broken down by yeast. (Apple skin has pectin, as does the surface of corn kernels.) If you ferment everything together there is so little methanol produced that it's undetectable. To get dangerous levels you have to distill it out of the fermented product.
    Ignore it. Everything in California has a Prop 65 warning. Parking lots, parks, Disneyland . . .
    That's called a starter. Get a flask, a stirrer plate and some sugar and go for it.
     

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