DIYeast: Microbe Portrait Gallery

The Microbe Portrait Gallery is a handy guide to the morphology (size, shape & color) of some of the most common brewing and fermentation bugs, as shown on agar plates and on a wet mount under 800X light magnification (bacteria are at 2000x, because they’re so damn small).

If you don’t have a microscope yet, there are (relatively) inexpensive models available which have an immersion oil lens that allow you to see bacteria like Lactobacillus, as well as yeast in crazy detail. The AmScope compound microscope with immersion oil lens is kind of a beast considering how much cheaper it is than a typical lab scope.

A few things to note:

  • Colony plate morphology can change depending on the medium they are grown on as well as environmental factors. All pictures here are on DME agar plates, except Lactobacillus cultures which grow best on a MRS medium.
  • Morphology under magnification may vary depending on whether sample was taken directly from plate or from a solution. In situations in which they vary (like when Brett demonstrates pseudohyphae), both types are shown.
  • Brilliant Green was used to stain Brett cultures under magnification, Safranin all Lacto cultures, and Lactophenol Cotton Blue all other yeast cultures. Those dyes were chosen mostly because we like pretty colors, but LCB is ideal for differentiating yeast from other microbes in mixed cultures.
  • All cultures, unless otherwise stated, were originally sourced from a major commercial yeast supplier. Some samples had signs of other cultures being resident, which is why some variations in morphologies may be present.
  • Looking for a specific microbe? Let us know and we’ll try to source it.
Brewing Microbe Portrait Gallery
Species/StrainAgar MediumAgar MorphologyLiquid Magnification Plate Magnification
Brettanomyces lambicusDMEBrett Lambicus Plate Morphology - Early PhaseEarly PhaseBrett Lambicus Plate Morphology - Late PhaseLate PhaseBrett Lambicus 800x MagnificationLarge circles are the Brett cells
Brettanomyces bruxellensisDMEBrettanomyces Bruxellensis PlateBrettanomyces Bruxellensis Liquid Magnification (800x)Brettanomyces Bruxellensis Plate Magnification (800x)
Brettanomyces bruxellensis trois*DMEBrettanomyces Bruxellensis Trois PlateBrett Trois 800X MagnificationLarge circles are the Brett cells
Brettanomyces clausseniiDMEBrett Claussenii Plate Morphology - Early PhaseEarly PhaseBrett Claussenii Plate Morphology - Late PhaseLate PhaseBrett Claussenii 800x MagnificationLarge circles are the Brett cellsBrett Claussenii 800x Magnification (taken from plate)
Lactobacillus delbrueckiiMRSLactobacillus delbrueckii Plate MorphologyLactobacillus delbrueckii Liquid Magnification (2000x)
(kimchi sourced)
MRSLactobacillus (from Kimchi) Plate MorphologyLactobacillus (from Kimchi) Under 800X Magnification
PediococcusMRSPediococcus Plate MorphologyPediococcus Liquid 2000x Magnification
Saison Strain
(S. cerevisiae)
DMESaison PlateSaison Liquid Magnification (800x)
Weizen Strain
(S. cerevisiae)
DMEWeizen PlateWeizen Yeast Liquid Magnification (800x)
Lager Strain
(S. pastorianus)
DMELager PlateLager Yeast Liquid Magnification (800x)