First Sake

I just made my first sake using the directions and ingredients from www.homebrewsake.com. It turned out good, but it does have a slight yeasty/moldy/funky taste. Is this normal? If it is not normal, what can I do to help prevent this in my next sake?

I skimmed through the web site and the recipe is solid. Not too much kome koji and the stepped process looks correct. Only thing I don't like is the addition of lactic acid or acid blend. Sake should not need that if done right. Through the process you get lactic acid built up anyway so why add more?

The yeasty taste I only get if I drink the sake right after straining solids and it is still milky. So that flavor depends on if you cleared the sake or drank it without clearing it.

But the moldy and funky notes you mention may be that your yeast to mold count was tipped too high towards mold and not enough towards yeast. In the early stages of sake it is really important to only let the sake be warm in the short times you need it. The mold grows there and produces Amalyse. Once you have enough amalyse you chill it down stopping or slowing the mold but being within the yeasts tolerances, it is allowed to keep multiplying. The Amalyse enzyme does not need active mold and also works at low temps and so the Amalyse and yeast work together. In the final couple weeks the alcohol content gets so high it kills off the molds and the cheesy/moldy tastes go away as long as there was not too much mold to cause off flavors.

There are a lot of variables to sake and few make it right the way they want the first time so do not despair. When looking back at your notes/memory I hope the above helps you figure how you can improve the next batch.

Yes thanks. I think the problem is when I made the koji it was to humid for too long. That probably produced too much mold. Also I might have fermented about 5F degrees too high.

Yea I only make my sake in late December so I keep the jars outside and can be sure I keep the temps below 50*F. Sounds like you know exactly what happened so your next batch should be great. What yeast did you use if you do not mind me asking?

I used Wyeast 4134 Sake Yeast

Ok cool, that is a good yeast to use, makes great sake. Another one that makes a fine sake is lalvin k1v-1116. It works well in those super low temps and adds more floral notes over the traditional sake flavors.