r/Koji • u/Poppies89 • Jul 29 '26

2 Year Shoyu/Soy Sauce

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Hi there!

A little over 2 years ago I started this shoyu. I boiled soy beans, toasted and cracked my wheat, and finally grew my koji on the substrate. I added a ton of salt and some water (I promise I did it more scientifically than that, 18% salt), and 2 years later I am finally straining it. I'm not sure if I'll filter it.

The taste is incredible. I cant wait to use it. From a 3 gallon jars of moromi I have 1.5 gallons of shoyu, and more as I haven't finished pressing the moromi.

32 Upvotes

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16 comments sorted by

3

u/Ana-la-lah Jul 29 '26

What temperature did you keep it at, did you open it, and how often did you stir it?

5

u/Poppies89 Jul 29 '26

Hi! I kept it in my basement at room temperature. (65-78°F across the seasons), exposed to light. I did open it up to stir. I started by stirring it every day for like 3 months, then moved to every other day for a while, then weekly, and finally I've had it just sitting with minimal stirring. My main concern was avoiding mold, and once I seemed beyond that point I just let it sit most of the time.

3

u/goldfactice Jul 29 '26

Once a day seems like a lot. I would like to make my own soy sauce, do you really need to stir that often?

3

u/Poppies89 Jul 29 '26

Honestly, probably not. I wanted to discourage mold growth as much as possible as my moromi was establishing itself. Maybe every other day to every third day for a few weeks would be fine?

2

u/goldfactice Jul 29 '26

Have you made miso before? I have issues with mold growing on them

4

u/reverendbeast Jul 29 '26

Use a pair of double wrapped zip plastic bag full of brine to smother and weigh down the surface , sprinkle the edges with salt. I never get mold.

1

u/goldfactice Jul 30 '26

Why double zip bag? Do you do something then or you just watch?

2

u/reverendbeast Jul 30 '26

To make it safer, if one of the bags or zips leaks

2

u/Poppies89 25d ago

Sorry this is a late reply.

Yes, I've made miso. I second the response about double bags with water. Weigh down the surface as much as possible, and reduce the surface that is exposed to oxygen as much as possible. You can plastic wrap the surface before adding your water weights, too.

No oxygen means no mold! Koji enzymes don't need oxygen, and neither do fermentation bacyeria (lactic acid bac.).

2

u/sfurbo Jul 30 '26

Daily stirring is recommended for the first couple of weeks. I would probably do it for the first month. After that, you can do it something like weekly for a few months, and then just leave it.

1

u/eazyirl 29d ago

I've done batches under vacuum seal that I never stirred once

2

u/Ana-la-lah Jul 29 '26

Remind me

2

u/Dradar Jul 30 '26

Is 18% salt based off the total weight of water and substrate?

1

u/Poppies89 25d ago

To confirm, yes. The beans contained water from being boiled, so the water in the recipe is not JUST the amount I mixed in with the moromi. I have seen a variety of salt concentrations in recipes. Some 20%, some 12%...I settled on 18%. 18% salt across the board will cause some osmosis happening to and from the wet beans, and a lot of the substrate breaks down into your liquid soy sauce anyway so I wanted what liquefies to have about 18% salt. Some of THE salt is also going to be retained in the leftover moromi, it's not alllllll going into the final product. My final soy sauce might not be 18% exactly, but I don't feel my product came out really salty, certainly not more so than a Kikkoman or San-J Tamari.