[pkrone]

My wife is an analytical chemist and as such, the school science fair has been inescapable for our kids.  Our daughter who is a senior this year analyzed my brewing grains, wort, hops, and beer for mycotoxins and pesticides.  She took samples during one of my brewing sessions.   She wanted to make sure livestock that may use spent grain for feed aren't getting anything nasty.   Apparently, cattle are much more sensitive to mycotoxins than humans.

The end result is what we brewers already know:  yeast are magical creatures.  The brewing process indeed extracted mycotoxin from the grain, so there was none in the spent grains.   The yeast metabolized the mycotoxin present in the wort so there was none in the finished beer.   Additionally, pesticides that were introduced by the hops were cleaned up by the yeast too!   Hooray beer!

 

[brewinhard]

Well, isn't that good to hear. Yeast are workin' pretty hard for us, aren't they. I wonder what happens then if the same yeast is used to repitch into another batch. Do they carry those toxins over or have they completely been positively metabolized?

[Pricelessbrewing]

I don't think I follow. Yeast aren't involved with unfermented wort, or with spent grain.

[Stevie]

I don't think I follow. Yeast aren't involved with unfermented wort, or with spent grain.

I had to re-read it at first. The point is the mash removed the harmful bits from the grain, and the yeast removed it from the beer. At least that is the simplified assumption. I'm sure there are all sorts of complex o-chem reactions affecting this.

[Hand of Dom]

So post-boil, the mycotoxin was still present in the wort, but post-fermentation it had been metabolised by the yeast?

[pkrone]

yep

[hopfenundmalz]

Was DON the toxin? When I toured a small Maltster, they said if the DON on incoming barley is to over the standard, it is rejected. I had to ask where it goes, the answer was it became animal feed.

[pkrone]

Yep, it was DON,  AKA "the vomit toxin".