Sucking eggs

[David H]

I recently heard on the radio that when someone did try to suck eggs he was later told he'd got it wrong and grandmas actually blew them. Besides reminding me of a similar phrase equally inaccurate, why is the phrase 'sucking eggs' at all if you actually blow them?

[Clanad]

Meaning, of course, 'don't try to tell people things which, given their age and experience, they might be expected to know anyway'. According to Partride's Slang, variations of this very old expression include advice against instructing one's grandmother to 'grope ducks', grope a goose', 'sup sour milk' and 'roast eggs'. Known at least by 1707, it was included in Jonathan Swift's Polite Conversation which had 'Go teach your granmam to suck eggs'.
It had been suggested that, in olden days, 'sucking eggs' would be a particularly important thing for grandmother's to do since, having no teeth, it was she was capable of...
(Source: Cassell's Dictionary of Word and Phrase Origins) (Having never sucked or blown eggs, I'm bereft of answer as to why)

[Quizmonster]

Last year, in the TV programme Born Survivor, Bear Grylls did his usual survival thing, this time in a desert in the USA. He has to find food, water and shelter with just a knife and a flint. On this occasion, he climbed up the wall of a ravine to find a bird's nest. There were two eggs in it and - for immediate sustenance - he rapped the shell of one on his lower teeth to open it and then sucked out the contents. Presumably in past times, grannies did much the same thing...though without necessarily scaling a cliff first!
So, maybe the saying nowadays should be, "Don't teach an ex-SAS man to suck eggs!"

[David H]

The odd thing was on the programme (Radio 4) they investigated all such things with a panel who actually tried them out, and when one did indeed suck the eggs and said how revolting it was, was told on his return that of course the trick is to make holes at either end of the egg to blow the contents out and save the shell intact.

Now why anyone, grannies included, should want to save eggshells and get rid of the egg (unless collecting them) is a separate mystery, but the main one being the official way to suck eggs to keep the shells is to blow them but it's still called sucking. I think we either need someone who's actually done it or someone who knows which programme it was on so I can ask them.

In either case I'd say it reverses the point of the saying as nowadays I doubt anyone under about 100 would know how this arcane practice was carried out...

[dundurn]

Only 59 but I've seen it done. It was used by egg collectors. A needle hole at either end of the egg, slightly larger at the rounded end. You have to make sure the needle punctures the membranes surrounding the egg as a whole and the yolk. Blow from the narrower end of the egg. Takes quite a bit of puff and doesn't completely empty the egg (bits of membrane are left behind).

[Quizmonster]

Blowing eggs, as described above, was standard practice in the 1940s, when most schoolboys were egg-collectors...done it myself many a time. However, the saying under discussion does not seem ever in its history to have referred to blowing ...always sucking. And - as has been suggested - I cannot imagine why grannies would want whole egg-shells.
I don't want to be vulgar, but perhaps the two words suck/blow are effectively synonymous in this context as they are in a particular sexual activity! (Perhaps that is what you were suggesting in the question, David?)

[David H]

It is the same phenomenon in reverse QM, and having seen a few of such threads deleted from various places in the past, despite not knowing the answer to this day, decided not to try for another go!

I'll try some of the historical sources for sucking eggs as the radio programme seemed to show it's not nearly as simple as we think. If you visualise sucking an egg the product would be raw and very unlikely to be edible in the usual sense of the word. But if not, then why do it at all I wonder?