Bulk method - 2kg tempeh, 5l container

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Bulk method - 2kg tempeh, 5l container

Postby curtijam on Fri Jan 31, 2020 4:07 am

Hi tempehnists,

I've been working on up-scaling my tempeh production and thought I'd share my progress. I found a 5l glass / pyrex dish with fitted plastic lid that I am using to hold the tempeh as it ferments. I drilled small holes all over the plastic lid to provide air flow; the sides and bottom are fully contained by the glass but this does not seem to be an issue. I am fortunate to currently live in a country (Malawi) that has a climate warm enough to provide the fermentation temperature, so I no longer have to use an incubator system to keep it warm.

In fact the biggest problem I have is keeping it cool! After around 18hrs, the heat produced by the fermentation / mycelium rockets and I've recorded it at 45 degC / 115 degF. This resulted in patches of underdeveloped Tempeh in the centre of the block, presumably where the most heat is being concentrated. I've managed to get around this by placing the glass container on a wire cooling rack within a water bath. The water comes up ~2/3 the side of the glass dish, and although the water temperature does raise slightly it holds pretty close to the ambient room temperature. There is no fan or water pump at the moment. As you can see from the attached pictures, the top of the block is now beautifully uniform and consistent after 24hr ferment time. The underside view is slightly underdeveloped, next time I will try letting it ferment a little longer. However the 6x 330g blocks I get from the whole slab are all sturdy and have mycelium growth throughout.

I've found that keeping the beans on the firm side when I cook them is preferable to having them get too soft, as they tend to turn mushy when mixing in the starter powder and the slab collapses somewhat under its own weight, preventing airflow throughout the beans.

This is my full process:
  • Cover 1kg dried soy beans with ~4l boiling water, and leave to soak overnight
  • In the morning, drain off the soak water and replace with fresh water. Massage beans with hands to remove the hulls. Float off the hulls. I try and limit this step to 15-20mins max, any more sees limited improvement for the time spent.
  • Place soaked, dehulled beans into pressure cooker, cover with fresh boiling water and cook. I use a 6l Instant Pot (IP) and 1kg beans plus water is pushing the capacity limit of the IP - I keep the water level below the 2/3 limit line, otherwise I've found the seal / pressure weight can fail and it struggles to get to pressure and makes a big mess! I cook for 9 minutes high pressure, then leave to do a full natural release which can take 45min - 1hr. I've found trying to do a manual pressure release takes at least 15 minutes and is very messy, simpler to cook for less time (at pressure) and let it cool on its own.
  • Drain the beans, then place in a large baking tray lined with a tea towel. Place in a warm sunny spot to air / sun dry. I stir 2-3 times to help dry all the beans equally. I dry them until they lose the moisture sheen.
  • Stir 2 tbsp apple cider vinegar into the beans, followed by a mix of 3tbps rice flour and 1.5 tsp starter powder (rhizopus oligosporus). I find doing this in a large saucepan or other round container makes this easier.
  • Pour cooked, dried and inoculated beans into the glass container, and smooth over with downward pressure to make a consistent level slab. Cover with the plastic lid, drilled with holes. Cover with some form of mosquito netting to keep out flies and any other pests!
  • After ~ 18hrs, place glass container into a water bath, raised up on a cooling rack so the water can reach fully underneath the glass container. Regulate water temperature with ice cubes if necessary. Ready after ~24hrs full ferment time, ambient room temperature ~30 degC / 86 degF.
  • Split into 6 equal blocks, and refrigerate / freeze in tupperwear as required.

Next improvement ideas to try are a longer fermentation time (I've been reluctant to push too far as 24hrs fits in with my schedule, and I don't want to loose a full batch!), and to try an enclosed water bath with some form of water / air circulation.
Attachments
03_blocks.JPG
Split into 6x blocks of ~330g
03_blocks.JPG (79.79 KiB) Viewed 660 times
02_Bottom.JPG
Underside of slab
02_Bottom.JPG (79.69 KiB) Viewed 660 times
01_Top.JPG
top side of slab
01_Top.JPG (80.67 KiB) Viewed 660 times
curtijam
 
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Re: Bulk method - 2kg tempeh, 5l container

Postby curtijam on Fri Jan 31, 2020 4:08 am

Further pics
Attachments
05_Slices.JPG
330g block cut into thin slices
05_Slices.JPG (118.23 KiB) Viewed 659 times
04_Slices Detail.JPG
Detail of a cross-sectional slice
04_Slices Detail.JPG (68.38 KiB) Viewed 659 times
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Re: Bulk method - 2kg tempeh, 5l container

Postby irie1029 on Fri Jan 31, 2020 9:38 am

First off thanks for the Geography lesson. I never really heard of Malawi. I like your method on cooking the beans and will try that full natural release. I make natto and prefer a firmer bean as well. Honestly, the 20 minute and 10 minute natural is messy. I will try your approach on my next batch.

Your tempeh appears perfect I am going to have to try some to see how it compares to natto. Thanks for the insight!
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Re: Bulk method - 2kg tempeh, 5l container

Postby ArthurDent004 on Fri Jan 31, 2020 1:01 pm

Are you toasting the rice flour in the saucepan before adding the starter to it to insure the flour is free from contamination?

I saw one person that was using ice cubes to cool his water bath but didn't like how that was raising the water level in the container so he added a small aquarium water pump to the container and then routed to the output to a radiator with a cooling fan attached. The cooled water from the radiator was then routed back to the container. A thermostat was used to regulate when the water pump and cooling fan were active.
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Re: Bulk method - 2kg tempeh, 5l container

Postby Durgan on Thu Feb 06, 2020 5:32 pm

Your end product is excellent.
Durgan
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http://durgan.org/2011/
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Re: Bulk method - 2kg tempeh, 5l container

Postby curtijam on Fri Feb 07, 2020 10:01 am

Thanks irie1029. Let us know how the natto goes with that approach... it does take longer, but is cleaner and I like that I can click start then forget about it for an hour or so.

ArthurDent004 (great name!) - don't toast the rice flour and never had a contamination issue, so I feel that this would be an unnecessary step. Something to consider though should it ever happen in the future. Thanks for the tips on the waterbath :)

Thanks Durgan - big improvement since the first Tempeh pics I posted on here some months ago! And very rewarding to be at a stage where production is consistent.
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Re: Bulk method - 2kg tempeh, 5l container

Postby Durgan on Fri Feb 07, 2020 4:53 pm

You have a good technique.

I dehull by boiling beans for about 45 minutes and hand rubbing about five times pouring off the hulls.

Then I pressure cook for 1.5 hours by putting the beans in a colander in the pressure cooker. The beans are not in the water. Steam cooking if you like. The beans are still firm which seems ideal. I cook half a liter of dried beans per batch.

Then I ferment for 48 hours beans in a cotton lined mold with holes all around.I have five gallon pail set at 31C using a body warmer from a Chemist supply house.

I also do chickpeas almost the same way. Except only boil the beans in water about an hour instead of pressure cooking. Removing hulls is the same as for soy.

I use both, chickpea and soy, for my daily dose of protein. Canada produces many soy and chickpeas.
Durgan
Zone 5 Brantford, ON, Canada
http://durgan.org/2011/
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Re: Bulk method - 2kg tempeh, 5l container

Postby Durgan on Fri Feb 07, 2020 4:57 pm

I find tempeh is easier to produce than Natto and don't do natto anymore.

I order my starter for tempeh from Indonesia off the Internet. At first I use to make the starter but the Indonesian starter is always perfect so don't make it any more.
Durgan
Zone 5 Brantford, ON, Canada
http://durgan.org/2011/
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Re: Bulk method - 2kg tempeh, 5l container

Postby Durgan on Sat Feb 08, 2020 2:18 am

I have studied your photos and I question how little mycelium has permeated the beans. I believe fermentation should be such that the beans structure is destroyed. Ideally the product should be one solid mass. You mentioned the beans should b hard. This is questioned. I cook so the beans are soft but not mushy. In your tempeh the mycelium has covered he outer area of the beans, but completely missed the center. Looks good at first look but fermentation is incomplete. IMO.


Image
Durgan
Zone 5 Brantford, ON, Canada
http://durgan.org/2011/
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Re: Bulk method - 2kg tempeh, 5l container

Postby curtijam on Tue Feb 11, 2020 10:11 am

Durgan, I’ve studied your photos too and I can’t see the difference. Do you have any higher quality photos to give a clearer example of what you mean?
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