I have been reading a wonderful book about the Silk Road lately and, unsurprisingly, have learned quite a bit about sericulture. Now before people start putting in orders for silk scarves and such like, let me point out that there are certain things a silk farmer needs, and I have none of them. They are: a breeding colony of silk moths; a couple of large white mulberry bushes; plenty of time and a lot of patience.
The moths themselves only live a couple of days at most, during which time they breed and lay thousands of eggs. These eggs hatch after ten months – yes, that’s not a typo – during which they have been kept in extreme cold for five months and then slowly brought up to a steady 24 degrees for the next five months. They then hatch caterpillars, which are voracious eaters and could easily strip a mulberry tree in one go. They will eat nothing else but the leaves of the white mulberry for two months, and then (hopefully) will form cocoons in readiness to pupate. Keeping a few cocoons aside (for breeding again next season), these cocoons are scalded in boiling water to kill the creature inside, and then the silk is carefully wound off in a single strip, before being spun into a thread which is then dyed and used for weaving. Roughly 48 silk filaments will make up a single thread.
And that’s it. Silk thread takes a year to produce and cultivated thread (the process which I have described above) is preferred over wild silk thread because it is continuous and not broken – which happens when wild cocoons are found having hatched naturally. Each cocoon will produce approximately 1,000 yards of filament, although not all of it will be usable; it is said to take approximately 2,500 silkworms to produce one pound of raw silk.
Let’s do a quick bit of number crunching here. Two and a half thousand silkworms will produce two and a half million yards of filament which, when spun, will create roughly 52,000 yards of silk thread. That’s about twenty pounds of raw silk. Not a lot really, when you think about it. No wonder silk is expensive. And because the worms are boiled alive before the silk is collected, it also seems rather cruel (and certainly not vegetarian in any way); yet because the victims are insects, people seem to mind less about wearing silk – it’s almost as if the insects don’t really matter as much as they would if they had four legs and a tail.
A fascinating insight into a culture thousands of years old, but I won’t be treating myself to that silk scarf just yet.