Hermit

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I guess subconciously I knew it was wrong last night and did a quick google. This is from my browser history. I searched "gypsum chalk" to see if they showed up in the same context instead of just gypsum .

jmf143

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Why bother "troubleshooting" your bottle of gypsum at all? Its less than $3 for a brand new bottle. Throw yours out and buy yourself a new one.

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WoodlandBrew

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Ha ha. Good one. Why yes it is.

http://en.wikipedia.org/wiki/Sidewalk_chalk

http://en.wikipedia.org/wiki/Chalk

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IslandLizard

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Calcium Sulphate (gypsum) will dissolve and iononize partially in watery solutions, particularly when boiled. Then all kinds of reactions can occur in that mix, heat expediting the reaction processes. The Sulphate ion can be quite reactive and will bind to who knows what in that beer and create new molecules that don't smell so wonderful to us.

5 grams of gypsum in 5 gallons of wort maybe OK and do something right, 5 grams in an ounce of fermented beer is a whole different story.

Also, boiling beer doesn't improve its smell or flavor either.

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ajdelange

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I think modern dustless 'chalk' is sometimes made from gypsum but I just took a piece of the stuff I use to write what beers are on tap on the blackboard in the brewery and dropped it into some of my home made CRS and it fizzes so even if there is some gypsum in it there is also some chalk.

ajdelange

Recipes 

Unless you exceed the solubility produc (2.4 g/L) then it will dissolve and thus ionize completely. And it is less soluble at elevated temperatures than low.

What do you have in mind here? Boiled with hydrogen peroxide concentrated sulfuric acid is a very powerful oxidizing agent but those are hardly the conditions one finds in brewing. Sulfate should sail right through the kettle. It can be reduced by yeast to provide sulfur for amino acid synthesis but most of it will remain in the beer. This can be a source for jungbuket or skunking. It binds tightly to barium but we hope we don't have any of that.

Is that picture the head of a Varanid? Which one?

IslandLizard

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Are you a chemist?
My error. I forgot about the solubility of gypsum decreasing with higher temps, unlike most other compounds. I was replying to the boil experiment, and why it could smell bad.

Potentially there could be around 40 grams of gypsum in solution in a 19L batch (~5 gals) at 25°C. That's a lot of gypsum, way, way past typical mineral/trace content of water, and should be very detectable in many ways. I don't think anyone would like to cook or drink that.

No, nothing that drastic, it is still a watery sugar solution. But a complex one, particularly after we add an active yeast culture to the mix. There is a good chance some sulphate gets metabolized by yeast or binds to other molecules. In short, something changes, and it may be as simple as it just having an effect on our taste buds.

It would be nice to know how the sulphate ion plays a role in all this, although even in small concentrations it seems to make a difference in perception of bitterness and in Burton-on-Trent brews (Palmer). For good measure, being a hop lover, I've routinely added a good pinch of gypsum to my wort, but I've always questioning its true usefulness or what it does.

I was more fishing for ideas trying to find possible causes for the detected (off) flavors in conjunction with still fairly low levels of gypsum per OP's observation.

In that light, boiling a shot of beer with a good pinch of gypsum is an extreme application and well outside the scope of beer chemistry.

Radioactive barium would be a concern, yes.

Yeah, it's a albino. Not sure what kind, perhaps Nile. He isn't mine, neither is the picture. I adore them.

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ajdelange

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No. It's a hobby. Just as Varanid (and other) lizards once were.

They are pretty cool animals. I had a pair of Gould's for a while a Stokes', a Dumeril's and an Exanthematicus), kept a Niloticus (nasty thing) for a friend for a while, have been to Komodo twice and have had the thrill of catching Gould's in the wild (and one inside an office building). Now I have 2 dogs.