hist-brewing: cloudy meads (and haze in general)

George de Piro gdepiro at mindspring.com
Mon Feb 7 07:06:45 PST 2000


Hi all,

You can determine the type of haze in your mead or beer as follows:

Chill haze:  as the name implies, chill haze is formed when the beverage is
chilled. It is the result of tannin/protein complexes becoming insoluble at
cool temperatures, thus forming particles large enough to scatter light.  It
disappears within a few hours of warming the liquid to room temperature.

I don't think tannins are too much of a concern in mead, but the proteins
may still be able to form a haze.  If you add a few mL of 10% NaOH (sodium
hydroxide, aka draino, lye, caustic soda) to a small sample of the beverage
and the haze vanishes, it is a protein haze.

Yeast haze:  Some brewing yeasts (and many wild yeasts) do not flocculate
very well.  This may be more of a problem in meads because of certain
nutrient deficiencies.  You can confirm that a haze is caused by yeast by
counting the number of cells in the liquid using a microscope, or just
eliminating all of the other hazes.

Other microbiological hazes:  In other words, bacteria.  If your beverage is
so badly infected that you have a bacteria haze it will taste pretty off,
too.

Starch haze:  not an issue with mead (unless you added starchy vegetables
for some reason; potato mead doesn't sound too appealing...).  In beers
starch hazes can occur, especially in beginner extract beers in which
starchy adjuncts were steeped before the boil (why so many extract-based
recipes call for adding things like oats, rice, corn or Munich-type malts to
the kettle is a mystery to be pondered for ages to come).

Starch haze is easy to test for:  the beverage will yield a positive iodine
reaction (place a drop of iodine tincture in a small sample of the cloudy
liquid.  If it turns black or blue or some shade of purple it the liquid is
starchy).

How to get rid of these different hazes:

Filtration will clarify the beverage in all cases, but is not very
historically appropriate.
It also alters the character of the beverage substantially.  It is
impossible to filter a beverage if you do not own a filter.  I guess I've
eliminated that as an option!

Starch haze:  you're screwed.  Don't put starchy stuff into a non-diastatic
environment in the future.  I suppose you could buy some amylase and add
that to the beverage.  This will turn the starch into sugar.  Be aware that
this will provide new fermentable extract for the yeast (and other bugs)
that are present.  Don't bottle until the bugs have had a chance to eat this
new food, lest you create a case or two of rather randomly programmed time
bombs.

Chill haze (protein haze):  chill the liquid to as close to freezing as
possible and let it settle a while.  Then rack off the trub and enjoy your
clear beverage.  You could speed up the settling process by adding Isinglass
or gelatin.  The liquid has to be cold for these to work.

Yeast haze:  I have found that gelatin finings work very well on yeast
hazes.  Add about 6g (0.2 ounces) per barrel (31 gallons) and let it settle.
Chilling the liquid helps here, too.

Bacteria haze:  The flavor will be off regardless of the beverage's
appearance.  Best to start over, unless you were aiming for a wild flavor
profile.

Hope that was useful, have fun!

George de Piro

C.H. Evans Brewing Company
at the Albany Pump Station
(518)447-9000
http://evansale.com (under construction)

Malted Barley Appreciation Society
Homebrew Club
http://hbd.org/mbas


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