Lactic Magic - Souring with Lachancea
How do I use Lachancea souring yeasts like Lactic Magic?
Lachancea thermotolerans yeast (such as our Lactic Magic) can be used to both acidify and ferment worts, resulting in a one-step sour or tart beer with unique aromas and flavours while avoiding the more complicated processing steps of kettle sours.
This yeast requires specific wort production and handling to ensure consistent and desirable results for brewers. Please read our instructions prior to recipe formulation and use of this yeast.
Dextrose/glucose content drives lactic acid production
USAGE NOTE: A high rate of dextrose/glucose is required for noticeable acidity. To drop pH below 4.0, you must add 2.5-5% dextrose by volume. That is roughly equal to 2.5-5ºP or 0.012-0.020 gravity points, 25-50kg in a 10hL batch, or 0.5-1kg in a homebrew.
Lachancea produces lactic acid from dextrose/glucose. The glucose content of wort is not high when produced using normal methods. As a result it is ideal to increase the glucose concentration of wort, either by directly supplementing the wort with glucose/dextrose or by introducing a glucoamylase enzyme such as Amylo 300 which will cleave malt sugars into glucose units. In general, we recommend dosing a specific amount of dextrose/glucose since this will produce the most predictable results.
With 5ºP of dextrose we found the pH around 3.3-3.5
With 2.5ºP of dextrose, we found the pH around 3.5-3.7
With no added dextrose pH was around 3.9
Fermentation kinetics of Lachancea
Since this is a non- Saccharomyces yeast, it is not as efficient in wort fermentations. You should expect a Lachancea ferment to take 10-15 days to complete fermentation. Attenuation will range from 65%-80% depending on initial glucose concentration as well as wort sugar composition. This yeast does not ferment maltotriose very efficiently.
The acid production is typically complete within 72 hours/3 days of fermentation. Brewers looking for a faster turnaround may pitch a Saccharomyces strain at this point to rapidly complete fermentation. Note that if repitching the Lachancea is desired, then cropping a thin slurry at this point prior to the introduction of Saccharomyces is required as in a co-pitch environment, Saccharomyces will outcompete the Lachancea.
We recommend a fermentation temperature of 20-25ºC. Avoid temperatures over 27ºC as this yeast is not as high temperature tolerant as Saccharomyces.
Lachancea nutrient requirements and repitching considerations
This yeast has fairly high nutrient requirements. If your wort contains less than 12ºP from malt, we recommend supplementing with a yeast nutrient such as Yeast Lightning. This will help ensure timely fermentation and avoid sulfury flavours.
Lachancea also has a high requirement for oxygen, ensure that the wort is oxygenated well. We recommend a yeast pitching rate of 10 million cells/mL for original gravity up to 18ºP. Lachancea can be harvested and repitched but ensure that it is repitched at the pitching rate of 10 million cells/mL by performing a cell count.
Additional Resources:
Lactic Magic Technical Datasheet