TIL about "bog butter" and half a dozen other culinary terms that I've never heard of. Maybe for good reasons we don't make these food anymore? (banbidh, old curds, real curds, bainne clabair, sowens, flummery, etc)
A _lot_ of these things sound like various kinds of cottage cheese, yogurt and cultured butter. I would guess we _do_ make things they might recognize, just with modern standards of cleanliness.
Seems more like issues with production and markets. When my parents were growing up on a farm they made butter and sold it at market, but the creme freshe which was a byproduct of the whole process was considered to have no value and they cooked with it because it could not be sold. Now creme freshe is considered a luxury gourmet ingredient for fine cooking and commands a premium. Food fashions vary wildly.
I imagine the need for bog butter probably declined, in particular due to the advent of refrigerating things.
It turns out that burying things in the fairly cool, temperature-stable, low-oxygen ground is fairly decent at preserving things. Kimchi in Korea was traditionally produced in this manner.
