Fungi in barely can cause gushers?

[GodsStepBrother]

So I am reading "Brewing Science and Practice," I have been reading the chapter on mashing, and was troubled by this part:

"Several brewing problem are associated with microbial infections of malts.
off flavors may occur and there is always the concern that mycotoxins may
be present on poor malts. Particular attention has been paid to the possible
presence of aflatoxins, ochratoxin, zearalenone, dexynivalenol, fuminosins
and citrinin, which can produced by a rang of fungi infecting barley (Scott,
1996). Some, such as citrinin, do not survive the brewing process, but
others, such as deoxynivalenol, can survive into beer. Fungi also produce
factors that cause gushing (over foaming) in beers.

Now through out the whole book he gives example of how strict big brewers are when they get there shipment of grain. Now logically wouldn't it make sense that grains that are rejected by big brewers are leached off and sold to home brewers like us that do not have the laboratory to test our grain?

Wouldn't it be a queer idea to think that a lot of these stories about people getting gushers repeatedly batch after batch are in fact buying grain again and again from a home brew store that isn't aware there grain is faulty?

I know I am over thinking it and it is a long shot that this scenario play out, but just food for thought. This is just one little section of the book but wow it is an interesting read.

Albert...

 

[Justibone]

I doubt they are pushing off unsafe grain onto homebrewers. Some of those toxins are carcinogens, and the lawsuit liability would be a nightmare. It's far more likely, in my opinion, that they push it off into livestock feed, since cows won't live long enough to get HCC (liver cancer).

 

[pjj2ba]

We have a lab here that works on fungal toxins. These are typically produced by a few species of fusarium and penicillin fungi that attack crops, typically in the field, but can occur in storage (I have a friend who looked at this in corn silage). I believe these are screened for by the grain buyers and they will reject farmer's crops is the levels are too high. I would bet the maltsers are only buying grain that they know has been certified aflatoxin free.

 

[GodsStepBrother]

I doubt they are pushing off unsafe grain onto homebrewers. Some of those toxins are carcinogens, and the lawsuit liability would be a nightmare. It's far more likely, in my opinion, that they push it off into livestock feed, since cows won't live long enough to get HCC (liver cancer).

That makes alot of sense.

We have a lab here that works on fungal toxins. These are typically produced by a few species of fusarium and penicillin fungi that attack crops, typically in the field, but can occur in storage (I have a friend who looked at this in corn silage). I believe these are screened for by the grain buyers and they will reject farmer's crops is the levels are too high. I would bet the maltsers are only buying grain that they know has been certified aflatoxin free.

The author of the book also explain how alot of these Fungi, and in later parts of the book he talks about bacterial infections come from the malting phase itself. Not enough oxygen is introduced or alot of other things that can go wrong. I would also think that the maltsters test the malt before shipping it out but it still obviously gets rejected sometimes by brewers. Maybe they get different test results from the different labs each brewery has.

How is it that a fungi can survive the boiling process? Is it not sterile?

 

[dinertime]

The fungi aren't contaminating the final beer, because they will not survive the boil. In fact, most fungi produce compounds like this to protect themselves from other microorganisms, so it could even help to prevent contamination (though I wouldn't recommend adding them...)

It certainly seems reasonable that some of the toxins, or other chemical compounds, could survive a boil, but the living organisms (the fungi) would certainly not. However, if those compounds promote foaming, then that could lead to gushers, I suppose. It would be interesting to know what those foam-promoting compounds are.

 

[GodsStepBrother]

The author says "the brewing process" which includes boiling? So wouldnt that mean that "deoxynivalenol" would survive? I googled it and it is a fungus, correct?

 

[Justibone]

deoxynivalenol == chemical compound, I'd bet, from the name.

 

[GodsStepBrother]

Yeah your right I had to google a bunch of names and Deoxynivalenol is a Mycotoxin: is usually reserved for the toxic chemical products produced by fungi that readily colonize crops.

Then that makes sense. Thanks guys.