This was the basic Quenya word for “bread” for much of Tolkien’s life, appearing as ᴱQ. masta “bread” in the Qenya Lexicon of the 1910s under the early root ᴱ√M(B)ASA “cook, bake” (QL/59) and appearing again in Early Qenya Word-lists of the 1920s (PE16/141). It was ᴹQ. masta “bread” in The Etymologies of the 1930s under the root ᴹ√MBAS “knead” (Ety/MBAS) and the word appeared again in sentences from the Quenya Verbal System written in 1948 (PE22/119).

Starting with Quenya prayers in the 1950s Tolkien began to experiment with other forms, however. In the Átaremma “prayer” Tolkien revised mastamma “our bread” to massamma in the final version of the prayer (VT43/11-12), and in notes on lembas from the late 1950s he had massánië “Lady, breadgiver” as the title of the keeper of lembas (PM/404). This change seems to have been inspired by the Sindarin word lembas itself, and the problem of how to explain its final s rather than st. In notes probably from the mid-1960s (PE17/51-52) Tolkien wrote:

lembas “waybread”. This seems meant to be associated with Primitive Eldarin stems *LED “go” and *MBAS “bake” but is not readily derived from them according to Sindarin developments. Something like *leðbast would be expected.

He resolved this quandary by separating the basic word for “bread” from masta:

Assume a Primitive Eldarin derivation *mbassē “(baked) bread”. The other derivatives were *mbasta with short final, an infinitive or verbal noun formation denoting a single action of the stem .. and *mbazdā denoting the passive result of the action, and when used substantivally a single product of this: mbazda would thus mean baked or a baked thing ... In Quenya we have masse “bread” as a material, and masta “a cake or loaf” (zd > st).

Thus it seems that massa or massë was the word for “bread” (giving a clean explanation for the final s in lembas) while masta was a more general term for baked goods, including other items like cakes and loafs. Note, however, that Tolkien continued to use masta for “bread” in later sentences, including one in Late Notes on Verb Structure (LVS) from 1969: vá matuvatyë mastanya “you are not to eat my bread” (PE22/162).

Neo-Quenya: For purposes of Neo-Quenya I prefer to use massa as the typical word for “bread” rather than massë, to avoid conflict with other words like [ᴹQ.] masse “where”. I reserve masta as a more general word for baked goods, including bread but also other baked things like cakes and loafs.