Homemade Sake + Making Koji Rice

[Beerisgud]

Hey guys, I decided to give making sake a try and document it to reference for future batches, learn along the way, and maybe help others get a start. I really enjoy the taste of the drink and hope to make this a routine in the wintertime like they do in Japan. It’s all about temperature control, quality ingredients, and a nurturing spirit behind the paddle. The multiple steps/days involved give you something that needs a little more attention but are shorter processes compared to long brew days. If you are like me and wish you had something brew related to keep you busy often, especially during the outbreak of Covid-19, then sake might be a fun project for you to start. I hope lots of you are either brewing or supporting your local breweries by purchasing their beers!

Anyways, now onto the sake. First off let’s cover the materials needed for the entire process, keeping in mind that this is simply what I used and you may be able to substitute or improvise.

Materials:
12-24 can cooler (incubator for koji)
Cheesecloth
Medium/large capacity steamer
Heating element(brew belt/mat)
Thermometer (good instant read/probe/infrared)
Clean metal pan(cooling rice)
Small fine mesh sieve
Scale (can do lbs and grams)
10L fermenter (wide mouth)
Two one gallon fermenters for clearing sake(maybe just one, I don’t know what to expect for final volume)
Bottles for finished product
Air locks/lid with cheesecloth
Long spoon/paddle
Sanitizer
Temperature controlled environment
I use my kegerator or in the future utilize variable wintertime temps around my place like garage/basement/warm room.
Koji incubation temp range 86-100F/30-38C
Sake Temp range: 45-70F/7-21C

Ingredients:
Koji-kin (aspergillus oryzae spores) sold as “sake kit” on amazon
All purpose flour-this is optional and aids distribution of spores (I made rice powder with my very well cleaned coffee grinder)
Sushi rice (I got a 4lb Lundberg farms sushi rice(higher polish) for koji and 5lb kokuho rose sushi rice for additional rice)
Few liters Good spring water
Sake yeast like wyeast #9 (I used lalvin K1-v1116 this is not a traditional sake yeast but was used in previous post by arpolis with success)

That’s where I will leave it for now as I consolidate my pictures and steps here in my notes for the next post!

 

[Beerisgud]

I will state again that this isn’t as much of an instructable as it is a documentation of what I’ve done. I’m not even finished yet (in Moromi stage) so who knows how it will come out but it currently smells amazing in my kegerator!
Starting off with making the kome-koji. This is a process of propagating aspergillus oryzae spores on steamed rice and producing glucoamylase and alpha amylase, the enzymes that will convert the rice starch into glucose, called saccharification. Also, proteins are broken down to amino acids and peptides that will benefit yeast growth, flavor and aroma. Learning this process will make producing many other homemade food products possible such as soy sauce or miso!

Tested my incubator out and made sure that this is prepared before I made the rice. Clean the cooler very well and sanitize. I drilled a Tunnel/hole around the lid closure the size of my brew belt cord in order to be able to close. I placed a small bowl of water and the belt around the bottom. Also something to place the koji rice on. It was at 95F(35C)inside after tinkering with the temp on the belt.

I began by measuring out 400g of the lundberg sushi rice, rinsing the rice very well and soaking in water for 1-1.5hr on my counter. Then let rice drain for 1hr in a colander. Then steamed this in my steamer basket lined with a doubled up cheesecloth that was previously boiled and rung out. Large enough to be tied in a bundle. For now, fold the cloth over the rice. Be sure to not let the water run out or boil up to the rice. This process took about 45-50 min with this quantity of rice. While this cooks sterilize 5g flour in a pan on medium-high for seconds time until fragrant. Skip this step if you have an extra fine mesh sieve that can lightly dust the fine spores on the rice.

The metal pan was in the freezer for 15 minutes before the rice finished. Lined it with tin foil as it’s a seasoned pan. When I was finished I carefully removed the rice cloth ball with tongs and placed it on the cooled pan. It dropped in temp faster than I anticipated with this volume of rice so the pan is optional here but will be needed for the future larger additions. You want to stabilize at 86-100F(30-38C)and add your koji spores. I took my 5g rice powder and 2g koji in a small clean glass bowl and held the sieve closely over the rice as I tapped the bowls contents through. This helps evenly coat. Do it in 2 or 3 parts and massage into the rice with very clean hands or gloves. Do your best to coat each grain. Move quickly as to not cool the rice down too much. I ended up doing so at 75F(24C)for a rice temp due to the cold pan. I tied this in a nice flattened ball, in a baggie poked full of holes and placed in a preset incubator, the cooler. This is the zero hour of up to 48hrs of incubation.

In the following post I will paste my notes on my incubation timeline.

 

[Beerisgud]

Koji incubation timeline:

Koji in incubator (small 12can cooler) at 9:00pm at 76F(24C)internal temp. Kept incubator below 105F(40C)
9:00am internal temp was 96F(36C), stable. Plenty of condensation water bowl was removed. Occasional misting of container as needed to keep humidity up.
As first 24 hours continued it was a challenge to manage the temp with my current brew belt heat element. It does work but is touchy and can become too hot or too cold with minimal adjustments. It is, however, serving its purpose as possible with regular checks every several hours. As temps rose above 105F(40C)(highest recorded was 108F(42C))the bag was removed and lowered to 95F(35C)wrapped back up misted and placed back in plastic bag. I don’t know as of yet the overheating was caused by the koji naturally heating, the heat element, or the small size of my incubator. All will be subject to further experimentation. At 24:00 the rice had a noticeable spotting of mycelium beginning. No noticeable bad tastes or smells other than a funky mustiness like damp laundry (from damp cheesecloth or maybe I’m just smelling koji?) but mixed with the smell of steamed rice. So far I believe things look as they should!

At 34:00 the rice has overheated after not being checked in 8 hrs. Temp was around 114F(45C) which is too hot for koji. I’m hoping after opening stirring well and cooling to 92F(33C)that they will recover and continue to grow.
At 40:00 Appeared to be penetrated. Not fluffy but coated and into the grain (due to frequent stirring?) Continued to incubate until 48hr mark. Smell has become quite intense, nutty, funky mustiness. Try and stabilize temps better to avoid stirring to cool and obtain a fluffier end product for next attempt. Use a temperature probe. Main goal is to keep around 95F(35C) for entire 30-48hrs for optimal propagation. Removed the finished product from the cheesecloth and into a new baggie and weigh in grams. I got 564g finished koji from 400g dry rice. Place bag in fridge in a container. Here is a close up photo at 48hrs.

 

[Beerisgud]

Here we will be starting the moto/shubo or yeast starter.
Here are some notes on the next 48hrs of Moto before the yeast is pitched. You will see I did the math out for all future additions. We start with 7% and double up until the full 100%.
I based my calculations on my Koji final weight-564g at 48hr of incubation. Keep the koji refrigerated or freeze in their separate addition amounts for a later sake batch. Do not freeze whole, will be pain to separate for additions. 2-3 weeks fresh or 3 months frozen shelf life.

Sake ingredients ratio

25:100:160

Koji:rice(dry):water

564g:2,256g:3,610g -this is total 100% weight and will use these numbers to get the following percentages.

Combine first 7% of ingredients stir well and room temp for 48 hrs. Add yeast then chill for 12hrs 50F(10C). This is the shubo/moto or yeast mash starter. See day 1.

Additions calculations:

Shubo: 7% koji: 39.48g rice: 157.92g water: 252.7g + sake yeast after first 48hr past (lalvin k1-v1116 was used)

Hatsuzoe-1st additions: 14% koji: 78.96g rice: 315.84g water:505.4g

Nakazoe-2nd additions: 26% koji: 146.64g rice: 586.56g water: 938.6g

Tomezoe-3rd additions: 54% koji: 304.56g rice: 1263.36g water: 1949.4g

Day 1: weigh, rinse, soak, drain, steam, cool 7% rice (phew!) put in fermenter, add 7% water, add 7% koji. Stir well and start zero hour of 48hrs before yeast is pitched.
8:00pm: ingredients are in fermentor, start of shubo/moto (room temp 65-70F/18-21C)
Notes: absorbed all liquid pretty quickly

Day 2: 8:00am stir
Day 2: 8:00pm stir
Notes: liquifying by 24hr

Day 3: 8:00am stir
Day 3: 8:00pm (48hrs later) stir then pitched my rehydrated lalvin yeast. I boiled 2oz water, placed in sanitized mug, cooled to 95F(35C) added yeast, let rest for 20 min then pitched into fermenter and stirred well.
Here is a photo of my fermenter with 7% volume before my yeast was added. My lid is not airtight and I made the mistake of making a hole for an airlock. It’s useless but I put one on for safety. The thick paper rag (substitute-cheesecloth) is providing a bit of a better seal but still allowing CO2 out. Do what you can make it work, right?

Then cool rest at 50F(10C) for 12 hours in kegerator.
12hrs later, remove from cool temps and bring to room temp. My room was at 68F(20C)

Day 4: 8:00am brought back to room temp65-70F(18C-21C), keep for 3 days, stir 1-2 times daily.
Notes: Bubbles were forming, yeast looks happy.

Day 7: After about 72 hrs at room temp the mixture has taken on some sweet booze-y smells. The funky nutty koji smell is sitting on the back now. Moved to my kegerator in AM set at 55F then at PM dropped to 50F keep for couple more days. I slowly dropped the temp to be gentle on the yeast. You can simply place it in your cool location as long as it’s not below 45F(7C) stir once daily for next 3 days.

Day 10: shubo smells like vanilla and booze-y and the funky koji smell is fading even more after the 3 days cooling fermentation looks nice and active. Alcohol is now separating and on top of mash.

In the next post, the following Moromi stage will be done at room temp. This is the build up of the sake where we add all remaining 1st-3rd additions (14%/26%/54%) over the next 6 days. First day is koji, next day is rice and water, until all 100% is in the fermenter. I am currently in the middle of this process.

 

[Beerisgud]

Day 11: The shubo remained cool until my 1st addition of koji today. I decided to do the next 6 days of moromi stage at 60F(15.5C) by unplugging my kegerator located in my 57-60F(13.8-15.5C)basement and keeping it inside. I’ve seen conflicting information as to do this step cool or room temp. I figured I’d meet that in the middle. Let’s see how it works out. Today add 14% koji (78.96g) and stir well.

Day 12: weigh, rinse, soak, drain, steam, and cool 1st addition/14% rice. Weigh your 14% water and refrigerate too assist cooling rice before dumping into fermentor. Here is the mash at what is now a 20% volume.

Day 13: I added my 2nd addition (26%) of koji weighing at 146.64g and stirred well.

Day 14: Today I will be adding the 2nd addition (26%) of steamed rice and water. Updates/pics coming soon as the rest of Moromi continues!

 

[Beerisgud]

Day 14(continued): Just finished adding my 26% additions of both rice and water tonight. That’s 586.56g dry weight rice steamed, cooled, and mixed well with 938.6g cold spring water added to fermentor.

Here the sake is now almost halfway full (about 46%) of its total final volume. Tomorrow (day 15) I will add the 3rd and final koji addition (54%) More to come! Cheers

 

[Seamonkey84]

Wow, this process is intense. Keep up the work and updates!

 

[Beerisgud]

The 3rd and final additions of koji, rice, and water have been added to the fermenter over the past two days and stirred up really well. I’m loving the smells every time I open the fermenter. After the last rice/water yesterday I put it in the kegerator at 48F(9C). The work is done for the next 3 weeks as the mash ferments. Once it’s done, a separation from the lees or sake kasu with cheesecloth and a makeshift press with two steamer baskets will give me nigori. This will be cloudy stuff, almost looks like skim milk, but this will settle during clearing in a secondary. Updates to come in 3 weeks!

 

[Beerisgud]

Hey guys alright so I’ve filtered it and had it clear for a week or so in the fridge. I took a good sample today. It tastes sweet-tart and bright with a dry finish. I would say that my initial filtering was quite a task and I also think the final three weeks of fermentation was not long enough. The amount of Sake Kasu was abundant and I was left with a very cloudy liquid of about a gallon. I may need to tweak the water ratio a bit. After all is said and done, this was a worth while experience. I do enjoy the cloudy sake or nigorizake. Would I do it again? Yes. But I would most definitely do this in winter and utilize the ambient temps in my breezeway and basement to regulate. It was inefficient to run a kegerator for such a small product. I would also learn a better way of separating the sake from the kasu. I’m glad I learned the process of koji making for its other uses. Here’s a photo of the sake after trying to rack off the small layer of clear stuff. I did pull some cloudiness but it does taste great!

 

[jimyoung]

Awesome thread! I'm interested in trying my hand at sake.. did you collect stories and tips online, or, did you have a good book to start from?

 

[Beerisgud]

@jimyoung thanks! It was a fun experience. I would recommend getting a book. They are bice don’t have any recommendations but I did however read this thread

https://www.homebrewtalk.com/thread...e-difference-between-it-and-rice-wine.373347/
as well as this YouTube vid for koji rice



Next time I give it a go I will definitely be doing some more studying. Lots of things I would do differently. I want to give the simpler rice wine a try. The rice, dried yeast balls (instead of koji rice and yeast) and water all go in at the same time. It might be a better intro to the process. Good luck brew on!

 

[slmets]

@Beerisgud
Did you taste the mash at the early shubo stage (stirring twice daily stage)? Mine smells good, but I tasted it (after giving it a stir, I figured why not?), and there is a slight sour flavor, so I'm a tad concerned. I made a batch two years ago with highly polished short grain eating rice, and cold mountain koji, it turned out okay enough, sort of had a banana flavor. This time, I was able purchased all ingredients from an online brew store, so I'm excited, but it was comparatively expensive, so I really don't want to screw this batch up! Thanks for any observations you recall. Temperatures are currently maintained between 64-72 degrees (don't have a whole lotta control, it's spring in Utah).

 

[Beerisgud]

@slmets i only tasted when it settled out a bit after pressing. The more of the cloudy lees I had mixed in the glass the more tart. The pressing process I used wasn’t the greatest and I hope to figure out a better way next time and also let time take care of breaking down the rice longer. The clear glasses I had were awesome, melon-y sweet and bright with a slight tartness. I think the low temp ferment prevents lactobacillus from souring the sake. I hope to do this again this year and I will definitely do some updates if I do. The biggest challenge for us homebrewers is the pressing.

 

[passedpawn]

Excellent! I'm right behind you with this. I've got the spores here, almost got my koji started this weekend. Maybe this later this week. I bought the spores on Amazon, these:

https://www.amazon.com/dp/B07XKBPZJT/ref=cm_sw_em_r_mt_dp_X653J4N97VNYM298ZVY6?_encoding=UTF8&psc=1

 

[passedpawn]

For reasons I can't recall, I ordered Wyeast 4347. This is not the same as Sake #9, which is what I thought I was getting. O well, we'll see how it goes.

 

[RemyBD]

Hello! I'm starting to try my hand at brewing sake, making kome-koji from the koji-kin spores sold by Vision.
As I'm already thinking about all the fun experiments to do, I was wondering if you could use some other grain along with rice during the fermentation process, but not in the making of kome-koji itself. Like, making a blend of 80% rice and 20% other starchy grain (thinking of buckwheat for instance).
I may have missed it but I couldn't find any answer online

 

[Beerisgud]

@RemyBD The combination of inoculation of koji-kin and using higher polish sushi rice liquify the rice easily in fermentation. Bringing in another grain to the mix may work if you mash them but in that case you would be adding only the collected liquid, as the grains don’t breakdown. If you use any unmalted grain you’d do a cereal mash and maybe add this or that lil side wort you make after all the rice additions have been done? Any additions to this sake process I would be curious to see what happens. I just don’t have the money or time to experiment like this haha. I like sake just the way it is (if I can actually make it properly lol) but hey I’m all for experimentation!

 

[Beerisgud]

@passedpawn i think that wyeast 4347 is a great choice, I’ll be getting a sake yeast the next time I do this. Which I’m hoping will be over the summer and just keeping my kegs a bit warmer at like 48F for the sake yeast to still do its thing.

 

[RemyBD]

@Beerisgud Oh thanks, so from what I read about Cereal Mash, it seems to be just like a standard beer mash?
As the idea is to gelatinize starch present in malt, do I still need to do a Saccharification rest to extract sugar, which would be directly available for the sake yeast, or would a simple gelatinisation rest (like, around 60°C for barley) be enough to make starch available for koji-kin to convert into sugar?

 

[Beerisgud]

@RemyBD I’ve never done a cereal mash but I believe you’d bring it to like 70c for 5 min then bring to boil for 30. Then this is added to main mash and proceed as normal. I’m starting to rethink this whole thing. The idea is to let the spores eliminate doing the mash conversion. I know that the koji-kin can be grown on other grains but preferably polished like pearl barley or something like that. Maybe you could just steam any other polished grains and toss it in the mix. Or make your just your koji with your desired other grain. The biggest thing is making sure the koji can take over these other grains, if not they should be mashed.

 

[passedpawn]

I got some massive fuzz on my koji starter. I'm in the middle of the rice infusions now. After a few days, there was some fluid in the bottom of the container, so I skimmed the mold off the top and left the rest. I have a couple of buckets of the goodness going now. Some experiments. Maybe I'll document here later.

 

[passedpawn]

I never closed the loop on this. I ended up with 5 gallons of rice vinegar!!! Probably should have kept it, but was pretty disgusted so I tossed it.

I've got two more batches going right now. Hoping for better outcome.

Batch #1: traditional, with sushi rice, koji, and Wyeast sake yeast
Batch #2: cheapo jasmine rice, alpha and gluco amylase enzymes (no koji), and Lalvin wine yeast.