Re: Yellow/warm yeast/white scum

>Anne in rainy green Santa Cruz
>**Look in the yellow pages (do you call them "yellow pages" in Canada?) under
>"Brewery Equipment & Supplies."

Hi Anne -- Yes -- In Canada "yellow pages" are "Yellow Pages". I wouldn't
be surprized if they were "yellow" world-wide. :)


Mike wrote:

>A couple thoughts about warm yeast... First increasing the
>temp. does increase their metabolism, which makes them repro
>duce faster, therebye useing up the sugar faster, producing
>more CO2 and alchohol. All types of yeast have different
>tolerance to alchohol. When your homebrew reaches that
>level the yeast dies off. The alchohol level is only about
>5 or 6%, so its not worth drinking. Of course this assumes
>the sugar level was high enough to attain max alchohol. If
>the sugar level is low the yeast just eats it all and dies.
>I am presently trying WINE yeast due to its high achohol
>tolerance. 12%. It should use more of the sugar and last
>longer. I apply this to my homemade beer all the time..

Somewhere along the line I got the impression that *dying yeas* is what
releases the CO2. Is this wrong? Is it living, eating yeast that produces
the CO2?


Franc wrote:

>Yes it does. What you are observing is "iron bacteria"  If you look
>closely it is actually bluish-grey film caused by iron consuming
>micro-organisms. This indicates sufficient iron present in the water.
>This phenomena can be often observed in tropical streams where there
>is a large supply of bivalent iron leaching into the stream. It is
>not dangerous at all and will dissapear shortly on its own.

Thanks for the info. Does this mean that I should stop adding fertilizer
until it disappears? What do you mean by "sufficient"? Does this mean that
my iron test kit lies when it says 0.05? I understood planted tanks would
be better at 0.1. Will this "iron bacteria" go away in time no matter what
the iron level in the water? Sorry for all the questions but I have a mania
about knowing the "why" of things. :)