# Sulfur off-aroma in saison



## Meddo (31/10/17)

Hi all, I'm after some advice please as I'm about to re-brew a saison from earlier in the year. That one did fairly well at the Gold Coast homebrew comp with a score of 38.5 (and I really enjoyed it), but both judges noted a slight sulfur aroma and recommended looking into yeast health. After having it pointed out I think I could pick it (my sensory skills are appalling though) so would like to try to avoid that in my next iteration.

I struggled to come up with a good reason for why my yeast would be unhealthy in this particular brew. I've noted some of the details below and the only one that's jumping out at me is that calcium in the wort was only 30 ppm whereas I've read that the yeasties need 50 ppm for good health. Can anyone advise whether low calcium could lead specifically to an excessive sulfur flaw in the finished beer?

Other than that, the beer attenuated really well with WLP590 French Saison (apparent attenuation 90%, 1.040 to 1.004), so certainly no problems with health in terms of ability to chomp through the sugars. I pitched 240 ml of thick slurry CC'd from a starter (reckon it was 4L, unfortunately didn't record that) at 19 degrees and dosed with 90 seconds of pure O2, had big krausen and wildly churning critters when I checked ten hours later. Beer was allowed to rise to 24 deg on day 2 and 26 deg on day 3. FG was reached after five days, it was then given three days post-ferment holding at 26 deg for cleanup, dropped temp to 0 over two days, held at 0 for two more, and then bottled on day 12.

The only thing apart from the low calcium that I can think of is that I perhaps over-pitched - could this lead to excess sulfur smell? Anything else that I'm missing?

Thanks in advance.

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Water source: RO
Calculated qualities after salts dosing:
- Ca = 30
- Mg = 15
- Na = 17
- Cl = 59
- SO = 72
Mash pH measured 5.3 after lactic acid addition

Grist:
- Wey Bo Pils 75.5%
- Wey Wheat Malt 20.8%
- Carapils - 3.8%

Mash:
51 deg 10 mins
63 deg 45 mins
71 deg 15 mins

Boil 90 mins

Hops:
- Hall. Mitt. @ 90 mins and flameout

No-chill

Yeast = WLP590

OG = 1.040
FG = 1.004
IBUs = 28

Note 28 L wort split evenly to no-chill in 4x 10 L cubes, fermented in the cubes with glad-wrap over cube neck.


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## manticle (31/10/17)

Here is a reasonably comprehensive link on types of sulfur compounds including causes: https://www.morebeer.com/articles/sulfur_compounds_in_beer

Do you mean fart/rotten egg or something else?


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## breakbeer (31/10/17)

I can't tell you whether or not it would give off sulfur aroma, but as far as yeast health goes it could be the rapid change in temps. You mentioned that you dropped the temp from 26 to 0 in 2 days, that's fairly quick. Could've shocked the yeasties a bit


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## Meddo (31/10/17)

manticle said:


> Here is a reasonably comprehensive link on types of sulfur compounds including causes: https://www.morebeer.com/articles/sulfur_compounds_in_beer
> 
> Do you mean fart/rotten egg or something else?


Thanks for the link, I'll review it when I get home.

No certainly wasn't a rotten eggs hydrogen sulphide smell, the only thing that I could pick out was a faint "crispness" in the aroma that I thought might be what the judges were picking out. Perhaps the struck-match type thing.


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## luggy (31/10/17)

I wouldn't go above 24 degrees for French saison I've heard it can start to throw off flavours


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