Sake Saru News

Over the last few weeks I have been reading as much information on sake brewing as possible before I start gearing up to make the first batch of the year.

So far I have constructed two incubators for making Kome Koji and Tane Koji.  My first trial batch of Kome Koji dried out a little and spiked 47°C, which I thought was the end of that batch, however I persevered and mould growth increased , as pictured below.

Koji mould growth on rice at 36hrs

Note: When making Kome-Koji, in the early stages you should be able to detect a faint aroma, which will strengthen and start to smell like cheese with hints of chestnut and finally a sweet aroma.  As incubation continues the cheesy smell lessens and the chestnut and sweet aroma come to the foreground.  On tasting the mouldy rice, it  had a strong chestnut flavour with a very slight sweetness.

I then decided to let this batch go to spore and around 24 hours later I took this picture.

  

Approximately 24 hours after re-introduction to the incubator to induce sporing.

Koji starting to spore at 24hrs post reintroduction to the incubator.

Koji spores at 30 hours

  

Note: When Koji prepare to spore the pleasant aromas are replaced by a strong mouldy mushroom like smell.

As the Kome-Koji dries out the incubator starts to condense water which must be removed to keep dehydrating the Koji.   During this time relative humidity has dropped from 99% to 65% and thermal activity has also dropped to 34°C.  I am going to leave them until 48 hours to see what changes occur and then they should be ready to cool and dry out ready for storage and use.

For the next stage of testing, I plan to inoculate a small amount of rice and check the quality of the resultant Kome-Koji. 

Now that I have made Kome-Koji, I want to test the batch I have made by mixing a small amount of the Kome-Koji with water and leaving aside for 12-24 hours.  By doing this I can check the efficiency of the enzyme production in breaking down the rice, evaluate the sweetness of the sample and check the aroma that the Koji impart on the water.

In the above close up you can just make out a little foam and bubbles given off by the Koji.   After a few hours, I lifted the lid and checked the aroma, well it smelt really good just like fresh sake.  I also tasted the water and it had a nice sweetness and pleasant flavour.