2025 Draft Beer notes
Working with Czech Pils, Honey malt, and oats will make a lager with a beautiful frothy head and an excellent slightly sweet flavor profile.
Lemon Verbena and Chamomile will be added with the exception of a few ounces which will be added with the Turmeric “Bug” The .
Turmeric contains a chemical called Curcumin. Curcumin is a natural inhibitor of growth, so Turmeric needs to either be boiled extensively or can be added after the fact to both carbonate, fine and flavor the beer. It cannot be added during the boil as even boiling the root will not eliminate all of the Curcumin in solution.
Curcumin does not have the same effect on bacteria.
Curcumin inhibits growth of Saccharomyces cerevisiae through iron chelation
https://pubmed.ncbi.nlm.nih.gov/21908599/
Antibiofilm Effect of Curcumin on Saccharomyces boulardii during Beer Fermentation and Bottle Aging
https://www.mdpi.com/2218-273X/13/9/1367
“Addition of Curcumin to Bouladii can drastically reduce the metabolic activity of the yeast.” “ At the early stage of fermentation, curcumin supplementation considerably affected the yeast’s fermentation performance.”
“Our data revealed that adding curcumin to the brewing wort reduced S. boulardii growth and fermentation performance immediately after pitching. However, as time progressed, the strain S. boulardii exhibited comparable growth and fermentation performance in the presence of curcumin. The supplementation of beer with curcumin did not significantly impact the yeast’s overall growth and its ability to carry out the fermentation process. These findings align with previous research using yeast as a model organism, demonstrating the sensitivity of S. cerevisiae to curcumin through diverse pathways and mechanisms.”
“An investigation carried out by Minear et al. [45] showed that curcumin acts as an effective chelator of Fe(III) and consequently inhibits the growth of S. cerevisiae. Their research demonstrated that curcumin-induced growth inhibition is dose-dependent. Low iron level affects the DNA repair activity of Fe(II)/2OG-dependent dioxygenases [46]. A recent study by Stępień et al. [47] explored the effects of curcumin on both replicative and chronological aging in different S. cerevisiae strains. Across all analyzed strains, curcumin supplementation at concentrations of 200 μM and 300 μM was found to be a stress-inducing factor, led to a clear inhibition of the growth rate, and extended the mean doubling time.”
One thing to note in the study is that they did not taste the beer they simply looked at the growth rates. I have a hunch that stressing the yeast at the initial growth stage will produce off flavors that do not do the beer any favors. I instead am going to opt to add my turmeric in a final stage and use it as a fining agent that will remove yeast from solution.
• S-189, surprising easy yeast to work with. I just need cool my wort down to 50 before I pitch. In the past I pitched at around 80 and this resulted in metallic off flavors from stressed yeast.
o Yeast autolysis: When yeast cells burst or self-destruct, the iron ions in the yeast cell wall and cytoplasm can dissolve into the beer. This can happen if the fermentation process is abnormal, too much yeast is used, or yeast discharge is delayed.
o Ideally we remove curcumin during fermentation to prevent Iron Chelation and further stressing yeast.
o In my experience, stressed S189 tastes like metal.
https://www.mdpi.com/2218-273X/13/9/1367
