There is much confusion and many contradictory opinions
as to whether or not this approach actually works.
Tests by ourselves and others revealed the likely source of this
It appears that the benefits of this approach may be species or variety-specific!
(i.e. - it works with some kinds of peppers but not others)
More specifically, it appears that this approach works with some,
but not all, harder-to-sprout peppers.
It did not appear to provide any benefit for
peppers which were already fast and easy to sprout, and in
some cases actually caused damage!
With regards to species, it seemed to work well (or at least did not
cause harm) with the C. pubescens we tried, as well
as some harder-to-sprout rare C. chinense (habanero) varieties.
However, with some "cooking" varieties of C. annuums
we tried, not only did it not help,
it appeared to actually cause harm, by
delaying or even preventing germination!
In particular, its possible benefits with the C. pubescens
may make sense, as these originate in higher
elevations in the Andes mountains, are used to cooler climates than
other peppers, and may be more receptive to using cold to
break dormancy; in addition, the tannic acid may help to
penetrate the unusual seed coat which is unique to this
particular species of pepper.
It has also been reported to be of some benefit with tepin seeds.
Given the mixed results we witnessed, we would not recommend using
this approach for all kinds of peppers, however, it may be of
some benefit for certain hard-to-sprout varieties.
If you have had any experience (good or bad) using this
approach with any specific varieties of pepper,
tell us about it!