Like many fermented foods, tempeh is made with a starter, which is an inoculation of the beneficial organisms you want to cultivate during fermentation.
But for someone who wants to make tempeh at home, can it be made without a starter? Do you have to buy a tempeh starter, or can you make the starter yourself at home?
Let’s look at how to make tempeh without starter.
Can You Make Tempeh Without Starter?
No, you cannot make tempeh without starter.
Tempeh is made from the action of a very specific fungus, either Rhizopus oligosporus or Rhizopus oryzae, native to Indonesia.
Without spores of this fungus, you may be able to ferment soybeans, but you won’t be able to create tempeh.
However, that doesn’t mean you need to purchase tempeh starter culture. You may make a new batch of tempeh from any tempeh you have.
Can You Make Tempeh Starter from Store Bought Tempeh?
Yes, you can make your own tempeh starter from store bought tempeh.
While most manufacturers pasteurize tempeh to kill bacteria and promote food safety, pasteurization slows the fermentation of tempeh.
It does not kill the necessary spores to make your own tempeh starter and make your own tempeh at home.
Making Tempeh Without a Starter
Finished tempeh has living Rhizopus spores on it, so you can harvest these spores to make tempeh starter yourself. To make your own tempeh starter, you will need:
A Piece of Tempeh
A piece about 1 x 2 inches will make enough starter for several batches of tempeh. You can use homemade or store-bought tempeh.
A Wrapper or Container
Tempeh starter needs access to air in order to grow, but also needs to be kept moist to prevent it from drying out.
In Indonesia, tempeh is wrapped in hibiscus leaves and many people wrap it in banana leaves.
You may also use a plastic wrap and poke holes in it to allow air circulation.
An Incubator or Food Dehydrator
The tempeh needs to remain at a constant temperature throughout the growth process.
You need to be able to create moderate warmth and constantly monitor the temperature, while allowing air circulation.
If you don’t have an incubator, some people use a very low oven with the door open and a visible thermometer.
You may also be able to improvise an incubator with an electric warming pad and a thermometer inside a cupboard.
Rice flour protects and preserves your tempeh starter.
You will also need other ordinary kitchen equipment, like a food processor or blender, a kitchen scale, etc.
Read on to the next section to learn how to make tempeh without a starter.
Steps for Making Tempeh Without Starter
Place a piece of tempeh inside a container that keeps it moist but allows air circulation.
You might wrap it in leaves or parchment, or place it in a bowl, cover the bowl with cling film, and poke holes in the cling film.
You might also place it in a plastic bag and poke holes in the bag.
Put the tempeh in an incubator. The tempeh needs to remain at a constant 85-90°F in order for the spores to grow.
It will get warmer over time, as it ferments, so start it at the lower end of the temperature range.
Check the temperature every 4-6 hours and monitor the development of your tempeh.
You should see the tempeh become fuzzy within 12-24 hours. If the spores don’t grow within the first 24 hours, discard the tempeh, and start over.
Monitor the progression of your tempeh. Over the course of 24-48 hours, you should see:
- The tempeh starts to look fuzzy
- The tempeh develops white fluff
- The tempeh develops grey fluff
- The grey fluff develop black spots or patches
The black spots mean that the fungus has started to reproduce, and is ready to be used as a starter.
If your tempeh instead starts to look wet or gelatinous, or smell bad, discard the piece of tempeh, and start over.
When your tempeh has black spots, remove it from the incubator.
Cut the tempeh into small slices or pieces, and put them in a cool, dry place.
Allow the tempeh to dry for 48 hours.
Weigh your tempeh pieces, then weigh out twice as much rice flour as you have tempeh.
Use a food processor or blender to combine your tempeh with the rice flour to create your tempeh starter.
Put a date on the container so you know how fresh it is.
Using this method, you can make tempeh starter from any kind of tempeh, and have as much tempeh starter as you need without ever having to buy it at the store.
You can use this starter with any of your favorite tempeh recipes and make a new batch of starter whenever you need to.
It’s an easy and economical way to make as much tempeh as you like, whenever you like, without having to buy starter.
So yes, you do need a starter to make tempeh. But just because you need starter doesn’t mean you have to buy starter.
You can make tempeh without starter, by using the tempeh you have to make a new batch. Once you have done it a few times, it’s incredibly healthy, simple, and affordable.