What is "bog butter"

bog \bog\ (b[o^]g), n. [Ir. & Gael. bog soft, tender, moist: cf. Ir. bogach bog, moor, marsh, Gael. bogan quagmire.]

1. A quagmire filled with decayed moss and other vegetable matter; wet spongy ground where a heavy body is apt to sink; a marsh; a morass.

   Appalled with thoughts of bog, or caverned pit, Of treacherous earth, subsiding where they tread.
   --R. Jago.

2. A little elevated spot or clump of earth, roots, and grass, in a marsh or swamp. [Local, U. S.] Bog bean. See Buck bean. Bog bumper (bump, to make a loud noise), Bog blitter, Bog bluiter, Bog jumper, the bittern. [Prov.] Bog butter, a hydrocarbon of butterlike consistence found in the peat bogs of Ireland. Bog earth (Min.), a soil composed for the most part of silex and partially decomposed vegetable fiber. --P. Cyc. Bog moss. (Bot.) Same as Sphagnum. Bog myrtle (Bot.), the sweet gale. Bog ore. (Min.)

   1. An ore of iron found in boggy or swampy land; a variety of brown iron ore, or limonite.

   2. Bog manganese, the hydrated peroxide of manganese.

      Bog rush (Bot.), any rush growing in bogs; saw grass.

      Bog spavin. See under Spavin.

n. An ancient waxy substance found buried in peat bogs, probably the result of an old method of making and preserving butter.

"Bog butter" refers to an ancient waxy substance found buried in peat bogs, particularly in Great Britain and in Ireland. Likely an old method of making and preserving butter, some tested lumps of bog butter were made of dairy products while others were meat-based.