Post Punk Kitchen Forum

I recently ran a workshop on tempeh-making, and so now I have a fairly full complement of photos, thanks to my friend T, so I can finally do my tempeh-making photo essay.

Timeframe
Approximately 2 days.

Ingredients
To make about 1.5kg of tempeh (which ends up being about 6 ziplock sandwich bags' worth, if you're using those to pack the tempeh in), you will need:
- 2 1/2 cups of dry soybeans (about 6 cups soaked)
- 1 teaspoon of tempeh starter (dried Rhizopus oligosporus spores)
- 2 tablespoons of apple cider vinegar

Plus
- A large pot for boiling
- Clean towels (3 if using rolling pin method of de-hulling, 1 if not).
- A rolling pin or bottle (depending on your chosen de-hulling method - more on this later)
- A slotted spoon (useful, but not absolutely essential)
- Large clean dry bowl
- Ziplock bags with fork holes poked in them (*ahem*, not the filter!) OR a large casserole dish or the like, with alfoil for the top, also with fork holes poked in
- An incubator*
- Thermometer

Method

1. If you have a grain mill, crack your dry beans in it on a loose setting, just enough to split them. This will loosen the hulls and split the beans in half, which is important so there's enough surface area for the mycellium to fuse the beans together. If you don't have a grain mill, skip straight to step 2.

2. Soak the soybeans for 12 hours/overnight.

3. Dehull the soybeans. (This won't be necessary if you have a grain mill). There are two methods for this - the squeezing method, and the rolling pin method.

3a. Squeezing method: with the soybeans still in their soaking water, grab a handful and squeeze between your hand like you're trying to massage the base of your thumb. They should come apart relatively easily. Don't worry if some crumble a little, or some don't come apart. Relax and try to enjoy - you're gonna be here a while. It'll probably take you about an hour or so to get most of the beans. You can also pick hulls off the top as you go, cos you don't want them in your tempeh. Here's a picture:


Dehulling close-up


Gross slimy bean hulls

3b. Rolling pin method: Drain your beans and spread them out between two towels (make a soybean towel sandwich!). Roll the rolling pin vigorously over the beans until you've split as many of them as possible. This method is a lot more efficient, but less social and more energetic than the other method.


B spreading out the beans.


B splitting the beans with a rolling pin.

4. Put the beans in a big pot, add water, and par-cook them, skimming hulls off the top as you go. You need to get as many hulls out as possible - this will be fairly easy as they'll float to the surface as the water heats up. Give the beans a swirl with the spoon to make more float up. Also scoop off the bean scum as the water boils. This is where your slotted spoon will come in handy (if you don't have one, you can still totally do this, it's just less efficient). Don't worry if you get a few beans in with the hulls.
The beans should be cooked so that they're not soft enough to eat, but soft enough that when you bite into them, they kinda crumble in your mouth and are not totally hard. I've found this takes between 20-35 minutes, but time can really vary depending on the age of your beans, hardness of the water, etc etc.


G scooping off the bean hulls as they cook.

5. Drain and dry the beans. To dry, spread the beans out on another clean, dry, towel. Fold the towel over, and firmly rub them dry. They are dry enough when they're slightly sticky or tacky to the touch.


Me spreading the beans out for drying.


Beans get lovingly hand-dried.

6. Getting to the end of the active part of the process! Pour the beans into a large, clean, dry bowl. Add 1 tsp of spores, and 2 tbsp of apple cider vinegar. Mix these through really thoroughly (I usually add one at a time, mix, then add the other. I don't think the order especially matters). The vinegar makes the environment too acidic for unwanted bacteria to grow, so only the Rhizopus oligosporus can thrive!


J adding the spores.


Me adding the ACV.

7. Put your beans in their fermenting vessel.
7a. If using ziplock bags: Portion your beans into bags (make sure you've poked fork holes in the bags first). We used about 1 cup of soaked beans and spores and ACV mix per ziplock bag, but you could use slightly more than that. If you have the larger sandwich bags, they may hold more beans (we used those really little ones that barely fit a sandwich in). Make sure they're evenly packed, and about 3-4 half beans thick (maybe up to an inch or so? They can be a little thicker than this, but then they're tough to get out of the bags without cutting the bags open).
7b. Pour the beans into your casserole dish/cake tin/loaf tin/whatever. Mine is about 30cm x 10cm, I think that's probably a good size (I usually use about 3 cups dried soybeans when I make tempeh in this one, too). Spread the beans out evenly, and make sure they're not more than 2 inches thick - more than that, and the middle will get too hot whilst fermenting and you'll end up with mush. Trust me, I've seen it happen and it's really sad. Cover the dish with the alfoil with holes poked in it.

Sorry, no photos of this part!

8. Transfer your fermenting vessel/s to your incubator.
* Incubators: I use an esky/cooler on its side with a towel in it, and a heater pointing in. I set the tempeh on top of a cooling rack used for baking, to ensure air circulation. It's that simple. I've also used, with good success:
- An overheated bathroom or small room that nobody will go into too much, with the door shut (leaving the heater running the whole time/most of the time. (If you use the bathroom, and people shower, you may need to wipe away excess moisture that forms on the inside of your ziplock bags, to prevent the tempeh from spoiling).
- A cardboard box lined with alfoil, with a heater pointed into it.
- A styrofoam box, with holes poked in the sides and top, lid slightly ajar, with a hot water bottle (changed regularly). I haven't experimented much with this option, because I'm rarely home for 24-28 hours straight, so I don't know how useful it is, but it's definitely less wasteful, energy-wise.
Things to remember about incubators:
- Make sure you have a thermometer or thermostat to keep the temperature between 28 and 32 degree celsius.
- Make sure there is decent air circulation
- Make sure animals and children can't get at it
- Experiment! There are plenty of websites out there with ideas about much more high-tech stuff than what I'm using. And if the ambient temperature where you are is around 30 degrees C, then maybe you won't even need an incubator - just put your tempeh in an out-of-the-way place, maybe on top of the fridge or something.

Here's a batch of tempeh in my incubator:

Sorry that it's dark! This is a double batch, separated by a cooling rack. The orange glow you see is my bar heater, pointed into the esky. I move it further away as the temperature rises, and eventually turn it off completely at the end of the process.

Here's a lighter photo, different batch:


9. Wait! And check often. It'll take about 24-28 hours to do its thing. Here are some in-progress shots of a recent batch of mine:


Sides getting a little fuzzy! Maybe 18 hours in.


Mostly done now, probably 24 hours in.


Close-up pic of the mycellium taking over! It's basically done here.

10. When it's got a nice thick coating of white mycellium, possibly with some grey and/or black patches, remove your tempeh from the incubator and let it cool. In the last 8 hours or so, it will have started to produce its own heat, and will get quite warm to the touch. It's important to let it cool before putting it in the fridge or freezer so a) it doesn't heat up your fridge/freezer, and b) it doesn't keep fermenting whilst it's in there.


Resting tempeh babies, with slightly uneven mycellium coverage, but still definitely good!


Cross-section.

11. Cook and enjoy your tempeh babies!

Delicious!

Fantastic! Excellent instructions. I've never been a huge fan of tempeh, but maybe this will change my mind. Can't wait to try it. Thanks heaps!

Yay, sameness, thanks for the positive feedback. Homemade stuff is so much more flavoursome and amazing than storebought, I hope you'll be a convert!

This is awesome! I love it. Do you have to order the Rhizopus oligosporus online or something? I've never needed to go spore shopping before.

yay! thanks for posting this! i have been intrigued about making my own tempeh for quite a while now.

Yup, you order it online. I get mine from a little Tasmanian company. This is the address: http://www.tempehculture.com/. Postage is free and they send it to you in a little baggie inside a regular envelope, which I always find funny when I receive it (it's a fine beige powder).
I didn't add it initially because it wouldn't be useful for all the non-Australians on the board (I know there are several places to get spores in the US, for example. Not sure about UK and the rest of Europe.... or elsewhere. Although I imagine in Indonesia it wouldn't be so hard!).

Do it! It's so easy and so worth it. It makes tempeh heaps cheaper and more delicious - it's just the time investment, but after you've done it a few times, you can confidently leave the tempeh to its own devices during the fermentation time, so it's not too time-consuming.
I'm totally happy to help troubleshoot via this thread or PM or whatever. Even text message/phone call if you want, since we're both in Aus.

That's amazing! I really want to try this some day.

Oh! Some stuff I missed:

- Your fork holes (heh, I just keep saying that!) should be about half an inch apart.
- Don't worry if you don't dehull every single bean. If you choose the squeezing method of dehulling, my guide is to do it til you feel like you're gonna scream if you "get intimate"* with one. more. forking. soybean.
- When it's ready/nearly ready, tempeh smells kinda like mushrooms, or babies. It's sweet and delicious-smelling, unlike anything else. I love it.

Happy fermenting!

*Sandor Ellix Katz, author of Wild Fermentation and everyone's favourite fermentation guru, says (on dehulling and towel-drying soybeans) that it's rare that we get the opportunity to be so intimate with soybeans, so we should enjoy it.

In the U.S. cultures are available (last time I checked) from GEM cultures and the Farm (yes that farm, in TN).

Another heat sources for an incubator is a small light bulb (not CFL) or if you have an oven with a gas pilot that might be warm enough on its own, you may even need to prop the door open to get the correct temperature.

and as a side note, a little bit of an ammonia smell is okay. too strong and it means youre not getting good ventilation.

Thanks for chiming in, shortbus! I totally forgot to mention the pilot light + oven combo as an incubation possibility. And cheers for the information about where to get cultures in the US.

Oooh great guide. I really want to do this, but have to track down some spores and figure out how to heat it properly.

Wow, thank you for the super description!
I must say that I thought it would be much less work... but maybe I'll try it once! First I need to find the spores in Europe...

squeeeeeeee! i am so excitedfaced to make my own tempeh! it looks really easy to make and even though the process takes a bit of time, it looks really fun to me. i cannot wait to give this a go. thank you so very much for sharing. this just made my whole day. thank you!!!!

Wow, thanks for sharing! I've always wanted to try my hand at making tempeh.

Wow, gunk, great tutorial! Thanks so much for posting this. I love tempeh, and making my own is on my to do list.
I also learned in this thread just how much I identify with my user name. I keep thinking I was being talked about.

If you just bring beans to boil and then soak them overnight then they are much easier to dehull.

Wow, thank you! The photos make this seem a lot easier than I thought, I'll give it a go this weekend!