April 2023
General Updates
In order to make the most of these updates, the website, discord, and the weekly calls, we’re innovating everywhere we can. We’re rolling out monthly discussion topics so we can stay focused on our education. Each meeting has time set aside just for that topic. We’re doing a brewery focused group project each week or so where we try to find everything we can about them. We can thank Mike S. for that great idea. We’ll be starting with Terada Honke. Should be a fun dive into some traditional techniques.
Here’s what’s new:
This month was a huge brew month. Over 20 concurrent sake brews going on around the world. Some people were just starting their first and others were building equipment to scale up and go for the prime-time.
The Discord Summaries are perhaps useful, but there are a lot of repetitive items, many of which actually exist on the site …. this site: BrewSake.org. So, instead of copying that here, we’re just going to include new take-aways, outstanding items (research topics), and other big items we deem worthy of immortalizing here. Links might be a good example of something worth calling out, but the good thing is… Discord, unlike slack, lets us scroll back and search, so… search away!
The Weekly Zoom Call Summaries fall into a similar bucket, but we realized that each year, the topics we’d already discussed, are more informed. More voices have added to the collective and we’ve been gaining more experience. So, we’re going to set up months of the year where we spend time talking about what we’ve learned and also doing even more research, maybe even actual experiments, so that we can focus the group on something.
Coupled with that, each week we’ll see if we can get the collective to find as much as they can on a particular brewery and see if we can all learn something together through group study. Will it work? Dunno. We’ll try it and if it doesn’t, we’ll do something else.
If you have ideas for a weekly discussion, have an article topic you could contribute, or feel you can add to the community in other ways, please contact us. The global sake community needs your skills!
Website Updates
We added a search function so you can much more easily find what you are looking for. You can either search from the home page, or you can just go do brewsake.org/search
Additionally you can now see the full calendar of upcoming meetings on the homepage.
We still have a few outstanding articles that will be out soon. Just making sure they are the highest quality as possible.
Discord Summaries
Honesty.. this was an incredibly busy month. Far too much to summarize. We had probably 10 new people join and the dialog exploded. We’ve watched and cheered on the home brews and the brewers who have started to make the leap into commercial production.
Europe is on Fire with Sake Brewing
Our first brewer joined from Belgium. Patrick, a commercial winemaker and brewer in Italy, gave us a tour of his new custom-made koshiki. Henk in the Netherlands reminded us that you can brew sake in a 35sqm (375 sqft) apartment. (With a glycol chiller non-the-less). We connected with Tom at Kanpai London and look forward to his presence on the future Europe Saturday calls.
Speaking of which…we’ve setup 2 consistent calls with Europe each month, 9PM Central European Time (3pm Eastern Time).
Call Summaries
Jordan M. presented a with a sake-specific walk through of Bru’n Water.
Some notes from the presentation, but please check it out for a better rundown:
pH of Bru’n Water is assumed to be a a beer mashing temp of 65.5°C, so this calculated pH in the document won’t be accurate and you’ll need to measure it in your moromi directly. However, for moto/shubo, the initial calculation will be more accurate.
You will never hit the target numbers perfectly.
Summary of some common minerals
Calcium & Magnesium: yeast health. Magnesium is commonly source from Epsom Salt, but be careful, because it can inflate Sulfate levels
Sulfate & Chloride (not chlorine): helps determine bitterness and texture. In Miyamizu, these are fairly low and practically a 1:1 ratio.
Hard water can be difficult to adjust because it requires impractical dilutions in some cases. In the brewery, and RO system might be required, and in homebrewing, distilled water might be an easier way to avoid challenges.
Don’t expect perfection. You’ll get close, but due to the complexity of pH, temperature, and the basically the relationships described in stoichiometry, it’s just never gonna be exact. Realistically, there are plenty of other, more impactful areas in the process of sake brewing that you can focus on instead.
Other Notes
TOA (Taste and Odor Acceptance) test. - Reade H.
Water is an extremely soluble liquid and can take on the properties of anything it is stored in. It’s important to always taste your water before you use it and ensure that there are no aromas or flavors present.
If you are adding yeast nutrient to any water calculations it pretty much disregards the previously calculated chemistry. Be careful when using it if you are intent on replicating a particular water source.
Minerals affect the yeast, but what else do they do?
“Among the minerals in moromi mash of puffed brown rice, K, P and Mg ions contents were 10~13 times more than those of 75% polished rice, but Zn, Ca and Mn ions contents were about the same. By the addition of K, P and Mg ions, the digestion of steamed rice (75% polishing ratio) by rice-koji accelerated, and among them Mg ion was the most effective. The elution of a-amylase, glucoamylase and acid protease from rice-koji or steamed rice to the supernatant at rice digestion accelerated by the addition of these three ions, and among them Mg ion was also the most effective. The mineral concentrations for maximal rice digestion rate were 500 ppm or more for K and P ions, and 300~500 ppm for Mg ion respectively.” - Source
What are the common minerals sake brewers care about?
Documents spanning almost a decade show repeated water analysis results measuring:
Calcium: Accelerates production and excretion of enzymes of Koji (avg: 27ppm)
Magnesium: Essential for koji growth and yeast (avg: 7ppm)
Potassium: Essential for koji growth and yeast, accelerates fermentation (avg: 12ppm)
Sodium: Contributes to texture in mouth, can bring bitterness and salinity. “Sodium has no chemical effect; it contributes to the perceived flavor of beer by enhancing its sweetness. Levels from 75 to 150 ppm give a round smoothness and accentuate sweetness, which is most pleasant when paired with chloride ions than when associated with sulfate ions. In the presence of sulfate, sodium creates an unpleasant harshness, so the rule of thumb is that the more sulfate in the water, the less sodium there should be (and vice versa).” source (avg: 32ppm)
Phosphate: Essential for koji growth and yeast, accelerates fermentation (avg: 0.4ppm)
Sample of a water profile showing finished sake mineral levels.
Justin and Andrew summarized some of their takeaways of the Higuchi seminar on koji grown with US 70% Yamada-nishiki, 70% Calrose, and 70% Titan vs Japan grown 70% Yamada-nishiki.
I would appear that US Grown Yamada-Nishiki has a substantially faster absoption rate than it’s Japanese cousin. (y= 0.159x + 10.697. vs y = 0.046x + 12.04) where X is minutes of soaking time, Calrose was similar to the Japanese Yamada Nishiki rate, at y = 0.05x + 11.883, and Titan was just a bit faster at y = 0.07x + 11.517.
Japanese Yamada was the whitest in color but was also had the stickiest texture when steamed. The American grown Yamada had a browner color, but was less sticky when steamed. Calrose and Titan were both considered easy for steaming and washing.
The Higuchi strains were compared, with most of them producing similar enzyme ranges for each respective rice, but Hi-G and Super Hi-G were consistently much higher producers of Gluco-Amylase. (Hi-G: 65% more, Super Hi-G 130% more on average than the other strains). The US Grown Yamada actually produced 30% more gluco-amylase than it’s Japanese cousin in just about all the strains.
A note was made about ginjo and junmai styles
Higher Glucoamylase / a-amylase ratio, than “full-bodied” sake, but those numbers were 0.338 and 0.231 respectively.
Lower ratio of Acid Carboxy-peptidase / Protease ratio, 1.453 vs 1.613.
The numbers seem so small in difference that the take away was not clear.
Regarding Drying rice after Dekoji.
The final moisture content has very little effect on the enzyme quantities
The effective difference is simply how quickly the rice dissolves in the mash.
Reade H. Drown us In Water Calculations
Reade is helping us develop a proprietary water calculator that would be much more simplified for your sake brewing chemistry, but it’s not quite ready for distribution. We’ll update you when it is published.
Okay, that’s all until next time. Please Send feedback.
