Botanist Submits Starter Culture to Journal of Mycology; Proposes New Genus 'Saccharomycodes Sourdoughensis' Based on 47 Fermentation Cycles

The submission to the Journal of Mycology arrived on a Tuesday — 4,200 words, eleven figures, a 16-taxon phylogenetic tree reconstructed via maximum-likelihood analysis, and a 47-entry fermentation logbook spanning October 2024 through December 2025. The holotype specimen, designated EMRW-14 ("EM" for Dr. Elspeth Morrow, "RW" for rye-wheat substrate, "14" for the month of isolation), was at that moment sitting in a 78°F proofing box in the kitchen of a Victorian terrace in Portland, consuming a 1:3:3 feeding of bread flour, whole rye, and filtered water, and performing, as it always does, exceptionally. The paper proposed a new genus. Dr. Morrow, a plant taxonomist at Reed College whose primary research concerns the molecular systematics of Pacific Northwest lichens, had spent eighteen months building the case. The argument was clean: existing Kazachstania and Saccharomyces designations failed to capture the phenotypic specificity of EMRW-14's fermentation behavior. The culture's mean CO₂ production rate at 74.2°F exceeded published Kazachstania humilis benchmarks by 12%, its acid profile — measured via pH strip at 3.8 after a 10-hour bulk fermentation — showed a lactic-to-acetic ratio she described as "distinctly characteristic," and its hooch layer, a grey-beige supernatant appearing at approximately 6am during hunger events, exhibited a color she characterized in Figure 4 as "phenotypically consistent across 43 of 47 observed cycles." The reviewers had not yet responded. The submission was eleven days old. The genus name, Saccharomycodes sourdoughensis, carried an etymology section Dr. Morrow described as "the most straightforward part." The species epithet honored the substrate. The genus name gestured toward the organism's "functional kinship" with Saccharomycodes ludwigii, a fission yeast known for apiculate cells and weak fermentative capacity — traits EMRW-14 did not share, she acknowledged in the Discussion, but which "informed the cladistic neighborhood." The type strain was designated EMRW-14a, isolated from the October 2024 founding culture, originally propagated from a commercial starter she declined to name in the paper but had written in her fermentation log as "the Brett Kauffman culture (Bellingham, WA, gifted November 2023)." Holotype preservation, per mycological convention, required deposit in a recognized culture collection. Dr. Morrow had contacted the ATCC in February. They had not replied. She had designated her freezer's left crisper drawer as the provisional type repository and noted its coordinates on a laminated card affixed to the refrigerator door with a Reed College magnet. Her husband, Theo, a high school chemistry teacher, asked once whether the crisper drawer also needed to be published. "The location is already documented in the supplementary materials," she said. He had not asked again. The phylogenetic tree — reconstructed using ITS1 and ITS2 ribosomal sequences extracted via a Zymo QuickExtract kit and sent to a genomics core facility in February — placed EMRW-14 in a clade she described as "provisionally novel," sister to Kazachstania bulderi but separated by a bootstrap value of 94, which she had circled in red on the printed figure. The bootstrap threshold for recognizing a novel lineage was "conventionally 70, though 90 is preferred," she had written in the Methods. She had not cited the convention's source because she was, she noted, familiar with it from twenty-two years of practice. The fermentation logbook, Appendix C, ran to 31 pages. Each entry recorded ambient temperature (±0.5°F via Inkbird IBS-TH2 Pro), feeding ratio, hydration percentage (range: 78–83%, modal 80%), peak rise time, and a brief qualitative note. Entry 31: "Strong dome. Rise 4.1×. Lactic-forward aroma. Characteristic." Entry 44: "Rise 3.9×. Slightly cooler kitchen (71.8°F). Forgivable." Entry 47: "Levain yielded 38% open crumb on test loaf. Consistent with proposed phenotype. Genus designation warranted." She had used the word warranted with professional precision. The scoring pattern on that test loaf — a modified open-slash she called the "Morrow oblique," documented in Figure 8 and requiring, per the caption, nine developmental loaves to stabilize at a blade angle of 22 degrees to the surface tangent — was not, strictly speaking, taxonomically relevant. She included it anyway. "Phenotypic expression encompasses morphological outputs at multiple scales," she wrote in the Discussion. The Journal of Mycology's average review time was 68 days. Dr. Morrow had written this on a Post-it affixed to her laptop, next to the open submission portal tab she refreshed every forty minutes during bulk fermentation windows, which at 74°F and 80% hydration ran four to six hours. EMRW-14, designated Saccharomycodes sourdoughensis strain Morrow 2025 in all subsequent internal documentation, peaked at 4.3× rise by 9am that morning. Dr. Morrow entered it into Appendix C as Entry 48 before walking to campus to teach a graduate seminar on lichen phylogeography. The entry read: "Performing at genus level."