Here's my quesiton--rather than waiting until the water I've soaked the badkraut in is completely dry, what if I just sterilize it? Then I could use the salty water (in cooking obviously, but also in making new ferment, in situations where you're going to add water anyway) and save a lot of time. How much does the sun sterilize, to what depth do UV rays penetrate in water? I've heard that sun UV can sterilize water, but of course i've also heard that you can count on standing water to have pathogens in it, certainly it's teeming with micro friends. I'll try grandmother google.
:
ABSTRACT. Benthic photosynthetic microorganisms are widespread in shallow-water sediments, microenvironments that are commonly assumed to be virtually opaque to ultraviolet radiation (UVR). We used a newly developed optical microprobe to measure the submillimeter penetration of
solar UVR into a variety of these microenvironments. UVR trapping due to strong scattering occurred at the sur- face of some sedirnents, resulting in a surface maximum of scalar irradiance (E,) that could be signifi- cantly larger that the Incident radiation. In the subsurface, E,, was typically extingu~shedin a quasi- exponential manner, with attenuation coefficients (310 nm) ranging from 4 to 21 mm-', depending on sediment type. Ultrav~oletB (at 310 nm) was extingu~shedto 1"h of the incident between 1.25 and 0 23 mm from the surface W~thinthe euphotic zones of these sediments, however, the space-averaged UVBscalarirradiancewasveryh~yh,between15and33'!,,oftheincident Innaturalwaters,for example, the same parameter varies between 3 and g'
,of the incident. Thus, in fact, photosynthesis in these environments must develop under strong UV stress, and it must be regarded as potentially labile to the effects of ozone depletion.
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Not quite comprehensible to me.
a bit easier:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC348911/
short version--UVA is mainly what kills bacteria (not sure about big things like giardia are also killed? aren't they larger than bacteria?) UVA penetrates much deeper (shorter wavelength--<400nanometers--so attenuation is about 5% per meter!). So the issue is keeping the whole of the water in the sunlight. Angle is an issue. A
pond will have
enough shady bits that micro friends can always find a place to survive. Sort of like that depressing TV show where they live in the space station after the apocalypse and constantly disappoint and betray one another and have messy relationships. But there must be areas of a
pond that are pretty much sterile when the sun is at high noon in an equatorial region--if there's a pond still there at all, which there may well not be.
Another factor--at some point the salt is concentrated enough that it's sterile from that, or only the lactobacillus kinds of things could be living in that environment.
