Tuesday, February 22, 2011

Would you use GM wine yeast?

A question for the winemakers who follow this blog. Would you use a GM wine yeast?

There's a report today on decanter.com that the Canadian authorities have approved the use of a yeast called ML101 that is said to prevent headaches by producing fewer bioamines

It also enables the malolactic fermentation to take place at the same time as the alcoholic fermentation which is said to reduce the risk of wine spoilage*

Apparently the yeast has already been approved for use in the US and South Africa since 2006 so it's not new so I wonder how many other genetically modified yeasts there are around?

And surely winemakers could help to prevent headaches by reducing the amount of sulphur they use?

Just askin'.

* and somewhat alarmingly, according to this longer piece in The Vancouver Sun, the risk of 'toxic chemicals' forming as a result of adding malolactic bacteria. Is that genuinely a risk?

** and while on the subject of additives Jamie Goode has just uploaded this very interesting post on grape concentrate and Mega Purple


  1. Basically, I could care less about using GM yeast, enzymes, colouring, tannins, chemicals, oak extract, etc, etc. I like to make natural, healthy, complex, tasty, delicious, terroir-expressing wines; NOT some kind of toxic, chemical, artificially flavoured, artificially coloured alcoholic liquid.

    In answer to your questions:

    - No, I would never use a GM yeast in my wines. I wouldn't use any industrially produced yeast (even if it wasn’t GM’d). The wild strains that live in the vineyard and winery have been working perfectly well for me ever since I started making wine 8 years ago. I believe that they make for a more complex, interesting wine that expresses the terroir

    - "less bioamines = less headaches": I'm not a chemist. I'm generally very skeptical about these sorts of claims. They’re usually marketing ploys, used as selling points, or the facts have been distorted, or there are unmentioned disadvantages or side effects, etc

    - There's no risk of spoilage if your grapes are good quality and you keep your winery reasonably clean. It may be of interest to volume producers who use bad quality grapes

    -Malolactic fermentation. I don’t see why forcing the malolactic fermentation to take place at the same time as the alcoholic fermentation represents an advantage, as far as the quality of the wine is concerned. Making quality wine takes time! No doubt it would be ‘convenient’ for industrial wineries so they can get their wines to market faster. Toxic chemicals forming??? Shurely some mistake? Certain wineries ADD the toxic chemicals themselves!!! Sounds like another selling point, or scare tactics to me

    - Winemakers help prevent headaches? I’d say that 99.5% of headaches are caused by drinking too much alcohol, ie your classic hangover. The other 0.5% may be due to certain people (mainly asthma sufferers) who have an intolerance to sulphites or aldehides that are found in wine. So the best way for most people to avoid headaches is to drink less alcohol! Asthmatics and sulphite-intolerant people could look for natural wines that have no added sulphite but they should be aware that even if the winemaker hasn’t actually added any, the wine will always contain a small amount as it’s produced naturally during the fermentation process.

    "Salud y buen vino"

  2. Hey thankyou Fabio for that long and interesting reply. Very impressed by your grasp of colloquial English too and Private Eye in-jokes too ;-) Where were been working prior to Spain?

  3. Very clever of you, Fabio, to give useful advice to the old drunkards among us. Also, remind people that, “common hang-over” being a case of cerebral intra-cellular dehydration, one good way to prevent it - or decrease the severity - is to drink a large quantity of water at the time of the piss-up or just afterwards, and to ingest salt as well (either culinary table salt or sodium bicarbonate). One question though, can you substantiate the 99,5 % due to alcohol-overconsumption vs. 0,5 % to sulfite-intolerance (or allergy, not the same thing) or is it only a crude guess of yours? I’m interested in the source of this data.
    A la salud, slainte, lechyd da, gezondheid !

  4. Fiona, thanks - I used to read Private Eye and the Economist many years ago!
    Luc, I'll look out the source of the data for you. The figures are not a "crude" guess but my memory may be off a little bit.

  5. Luc,
    Here's some hard data:
    This study in turn quotes 3 other studies:
    a) by the FDA which says that 5% of the US population is sulfite-sensitive
    b) by one LC Knodel that says that 1% is sulfite sensitive, and
    c) by one Lester that says it's 0.5% of the pop.
    Go figure!

    This one gives a figure of <0.5% of the US population being sensitive to sulfites

  6. Thank you for the effort Fabio. I searched the literature some 7-8 years ago in connection with sulfite-sensitivity in antibiotic preparations. They came up with various figures, ranging from what you show to much larger figures. It all depends on how you define “sensitivity” and whether you allude to oral intake (most appropriate with wine, I suppose), or inhalation or parenteral administration. But maybe I did not make my point clear. What I meant is not the prevalence in the overall population, but the quantity (or proportion, if you prefer) of symptoms in wine-drinkers that can be attributed to either – as you rightly point out – overuse of alcohol or sheer hypersensitivity to SO2. You cannot say that, because only 0.5 % of the population would be allergic to SO2, the symptoms shared by both phenomena (roughly) are due to sulfites in 0.5% of cases and IPSO FACTO to alcohol in all the others. I thought you had those figures in mind. Thank you anyway. Ongoing issue. It’s 13.22 in Perpignan ... and I go back to my grenache-pruning now!

  7. Luc, of course! I didn't mean to imply that. I was just writing on the fly and didn't take the time to check that I was being absolutely clear. It's a bad habit of mine! 'Bon chance' with the grenache-pruning - I'll be going back to my Airén and Tempranillo soon :)

  8. Airén ? I know it’s the most planted (or was ?) variety in Spain, and yet, in spite of the large Spanish diaspora in my country of origin (Belgium), we did not use to see a lot of it. Large bunches and low density of plantation, or am I wrong ?
    Tempranillo, on the contrary: we seem only to see HIM (and its many variants). I must confess I had part of my practical experience with the grape in ... Portugal as well (Tinta Roriz or Aragonêz). Love it: one of the great cultivars in the world Fabio! Enjoy ... here the Tramuntana is blowing schist into my eyes!