Harry, you're absolutely right about my sloppy reference to hydrated lime
as calcium carbonate when the term more usually refers to calcium
hydroxide. If you do a search on it you'll notice that the term "lime" is
pretty loosely used, and I myself can never keep straight just which kind
of lime is which.
However, my point about the calcium in preference to sodium is still valid.
In the otherwise excellent equations you provide, I think you've confused
"bicarbonate" ions (HCO3-) with sodium bicarbonate (NaHCO3), therefore
telling only half the story.
Another way to look at it is that if you put sodium into your wash in any
form, whether as salt or baking soda, it has to come out in the spent lees
somehow (can't just disappear, unless you're running one of those high-tech
> My brews of late have been hitting a wall after the first two days
> promisingly vigourous fermentation, and I'm wondering if it's
> acid buildup.
> Is there any reason to not use ordinary hydrated lime (calcium
> for pH adjustments to a wash?
> I've got a big bag of it in the garage doing nothing, and I prefer
> thought of extra calcium finding its way onto my veggie garden
Are you sure about what's in that bag? Hydrated Lime is CALCIUM
HYDROXIDE (Ca (OH) 2). Description as follows...
HYDRATED LIME 's Properties:
Soft, white crystalline powder with alkaline, slightly bitter taste.
Slightly soluble in water, soluble in glycerol, syrup, and acids.
Insoluble in alcohol. Absorb carbon dioxide from air.
Skin irritant, avoid inhalation.
Mortar, plasters, cements, calcium salts, causticizing soda, white
wash, soil conditioner, disinfectant, water softening, purification
of sugar juices, accelelator for low grade rubber compounds,
petrochemicals, food additive, as buffer and neutralizing agent.
Chemical Description of Hydrated Lime
Ca (OH) 2 > 95 % Calcium Hydroxide
CaCO3 < 3 % Calcium Carbonate
H2O Free =< 0,6 % Water
SiO2 =< 0,5 % Silicon DiOxide
Fe2O3 =< 0,1 % Iron Oxide
Al2O3 =< 0.2 % Aluminum Oxide
The description for Calcium Carbonate (CaCO3) is as follows...
CALCIUM CARBONATE CHALK LIMESTONE
Calcium Carbonate: 96%
Magnesium Carbonate: 1.0%
Aluminum Oxide: 0.5%
Ferric Oxide: 0.12%
Water Soluble Matter: <0.1%
USES: Calcium Carbonate is used in the manufacturing of paint,
rubber, plastics, paper, ceramics, putty, polishes, insecticides,
inks, adhesives, matches, pencils, crayons, and by the
pharmaceutical industries. In analytical chemistry, it can be used
to detect and determine halogens in organics.
HANDLING: Avoid contact with skin and avoid ingestion. Use dust
respirator when handling. Be sure to store this material in a cool,
dry place. Since no exposure limit have been established for calcium
carbonate by OSHA & ACGIH, it is recommended that the product should
be treated as a nuisance dust 10 mg/m3.
Check your water and wort with a pH testkit BEFORE you add anything.
You need pH of 5 - 5.5 in your wort (wash) for yeast to be happy.
My guess is your water supply may be alkaline. This will kill yeast
much quicker than an acid environment.
The chemical reaction for the dissolution of limestone by an acid is:
CaCO3 + H+ <--> HCO3- + Ca++
(limestone) + (acid) <--> (bicarbonate) + (base cation)
You will see from this chemical reaction that the very thing you're
trying to avoid, sodium bicarbonate (HCO3-) is one of the end-
products, the other being calcium shale, the kind you see in
stalactites and in build-up in your old water pipes.
You're wrong about sodium finishing up in your garden. The reaction
of Sodium Bicarbonate and acid is described like this:
HCO3 + H+ <--> H20 + CO2
(bicarbonate) + (acid) <--> (water) + (carbon dioxide).
All you end up with is water and carbon dioxide, the same gas you
get rid of out when you breathe out.
(and so endeth the chemistry lesson for today) :-)