Clear and concise details can be found in the video below.

Place your oven light on. Note: only the light - not the oven itself.

Rinse soya beans and discard any discoloured beans.

Soak soya beans overnight in water.

The next day massage the beans and swirl in the water to loosen and remove the hulls.

As you agitate the water the hulls will float to the surface and can be scraped away.

As you massage the beans some will split in half. This is good.

Once the hulls have been removed discard the water.

Place in a pot with fresh water and cook till 80% done.

Drain off most of the water and add the apple cider vinegar.

Cook over medium heat until the vinegar and ALL of the water is cooked off. Beans should be dull and dry. Ensure you stir frequently to stop the beans sticking to the dry pot.

Place beans into a bowl and wait until the temperature drops to 35 Celsius. Stir them frequently to prevent hot spots or moisture forming. If beans are wet at all pat with paper towel.

Once the beans have reached the right temperature sprinkle over half the starter. Stir through then sprinkle the remaining starter through and mix well.

Piece the bag with holes at regular intervals using a skewer or tooth pick.

Place the beans into the bag and once full zip up the bag. Alternatively wrap in banana leaves.

Place bag on a wire cooling rack and smooth back so the beans are even and the air is mostly expelled.

Wrap the whole tray in a hand towel.

Place into your oven with the oven light on and do not disturb for 12 hours. Check the temperature inside the oven occasionally. Ideally it needs to be 28-34 Celsius.

After 12 hours it will generate its own heat and it can stay in the oven with the light off or move it to a warm place.

If you find it is getting cold (check with a thermometer) just replace it back into the oven with the light on occasionally.

The tempeh can ferment from 12 - 48 hours until it is covered with white mycelium.

When fermented to your liking remove from the bag.

Steam for 15-30 minutes to stop the fermentation process.

It can now be stored in the fridge for 7-10 days or the freezer for months.

Black or grey spots on the tempeh are fine and it is still edible. Green or pink spots and it should be discarded. Fresh tempeh should have a mild nutty aroma. If it has a strong ammonia smell it must be discarded.