This paper presents the Sociolinguistic Speech Corpus of Chilean Spanish (COSCACH) v1.0, a 9.3-million-word corpus
containing transcribed, lemmatized and morphologically tagged text, audio recordings and videos from 1,237 L1 speakers of Chilean
Spanish, as well as a control sample of 21 non-Chilean L1 Spanish speakers. The COSCACH is the first freely available corpus of
spoken Chilean Spanish of substantial size, as well as one of the largest speech corpora of any variety of Spanish. Following a
review of other Chilean speech corpora, I describe how the COSCACH was constructed, covering corpus design, speaker recruitment
and metadata collection, speech elicitation and recording, transcription, lemmatization and morphological tagging, and corpus
compilation. I thereby aim to provide a blueprint for creating modern, large-scale speech corpora suitable for phonetic,
sociophonetic and sociolinguistic research, in addition to traditional inquiry into semantics, lexis, grammar, pragmatics and
discourse.