Anything I’m Fermenting

April 24, 2008

Tempeh Part 2: Fermentation

Filed under: Tempeh — iwouldntlivethere @ 2:47 pm
Tags: , , ,

Step 12: Let ferment at 30 degrees for 36-48 hours.

I believe that my fermentation temperature for the first 12 hours or so was around 28. It subsequently started rising, and I had to remove the lights, one at a time. I eventually clued in to the fact that the tempeh packages were generating a lot of heat – so much so that I had to remove some of the packages from the cooler for a while and place in a drafty window to cool down. They remained quite warm to the touch for the last 12 hours of fermentation *.

Step 13: Cut in half while in perforated bags. Remove the halves and wrap in cling wrap. Consume, freeze and/or refrigerate as required.


Day 1, afternoon – grind soy beans to remove husks and begin soak

Day 2, late evening – cook soy beans, dry, inoculate, fill perforated bags (around midnight)

Day 3, morning – checked temperature – around 28, added a few lights into cooler. Noticeable mushroom aroma in cooler.

Day 3, midday – checked temperature: mid to high 30s! Progressively removed lights from cooler, until none remained. Fungal strands visually apparent.

Day 3, afternoon – temperature again has risen to high 30s, remove bags from cooler and set in window to cool off.

Day 3, afternoon – return bags to cooler after 30 minutes, but leave cooler open to dissipate heat.

Day 3, evening – bags still warm to touch, visually beginning to be covered by white fungal growth, but many individual beans still visible.

Day 4, morning – bags warm to touch, most covered completely by fungal growth; black spore areas near perforations in bags. Removed from perforated bags, wrapped in cling wrap, placed in freezer. During handling some white fungal areas crushed and oxidized somewhat – beans again visible occasionally (see photos).

* One of the bags (see photos) did not have a nice uniform white fungal coating by the end. It did have good coverage around the edges of the bag, but not in the centre. I believe this may be because it possibly overheated during fermentation. My reasoning is that I am fairly sure that the inoculum was evenly distributed throughout the soy beans, and even if it hadn’t been, it would not have been missing from such a large, symmetrical area in the centre of one bag. Further, the fact that the mold did take successfully around the edges of the bag, where it would presumably be cooler than in the centre, also point to heat damage. Some of the patties were verging on hot to the touch during the fermentation.

It can be seen on the area that has not been covered by fungal growth that there are nevertheless many fungal strands crisscrossing the soy beans. This would also indicate that it was not a lack of inoculum that caused this.

Another culprit may be anaerobic conditions, but I do not believe that this would have manifested itself in such a pattern.

The question remains, why only on one bag? I haven’t weighed the bags, but this bag appears to be somewhat thicker and heavier, meaning it would generate proportionately more heat than bags with fewer soy beans. As well, I accidentally left one of the bags in the cooler, while the others were out in the window. This may have been the one that stayed in the cooler.

As a result, I have left this one bag in the cooler in the hope that the fungus will be able to recolonize the middle area. As the fermentation has only proceeded for about 34 hours, I believe that I can safely let the bag continue to ferment for at least 12 hours if necessary.

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