A sourdough cake starter called "Herman"

My friend gave me a bowl of sourdough cake starter, called "Herman".  A bit of a google revealed that this cake starter has been around for a long time, maybe not this particular starter mixture in my kitchen, but the idea of this cake starter has been circulating since the 1980s or earlier.  There's actually an entire website devoted to it, as well as lots of newspaper articles and forum discussions.  Have you heard of it before now?

Herman when he arrived - pictured with my Danish bread dough whisk,
which was a very cool xmas pressie from a friend, and I've been using it at every opportunity

In its current incarnation, the mix is given away with instructions on how to look after it for 10 days.  It needs to be "fed" with flour, sugar and water on day 4 and 10, and stirred on each of the other days.  On the 10th day the started is split into four portions, three to give away and one used to make a cake.  The recipe that comes with Herman is for an apple and cinnamon cake, which I hear is delicious.

As you know, I love trying fermentations.  Fermenting is both a low energy and simple method of preserving food and way to partially digest and improve the food before we eat it.  I make and eat fermented dairy products (yoghurt, kefir and cheese), fermented beverages (ginger ale, barley water and beet kvass), fermented vegetables (picked cucumbers and sauerkraut), and I "soak" all grains and flour with kefir or whey prior to cooking.  In the case of rice and quinoa, if I want to cook these in the evening, that morning I put the grain in a pot with the correct amount of cooking water and a few tablespoons of kefir, and then cook them as normal in the evening.  For bread, I mix up the flour and water in the morning and add the yeast and bake it in the afternoon.  I hadn't figured out how to soak the flour for cake yet though... until Herman turned up.

Herman after being fed, bubbling nicely :)

Herman is a sourdough cake starter, which is similar to sourdough bread starter, but the difference is that the sourdough bread starter is used to both pre-ferment/soak the flour prior to baking AND to provide the yeast to rise the bread (for my bread method, I presoak with kefir and add conventional bakers yeast).  In comparison, the cake starter is ONLY used to pre-ferment/soak the flour, as baking soda is used to rise the cake.  This seems to have caused some confusion on some of the forum threads that I read, in which people wonder a) why the yeast is needed to bake the cake (answer: its not needed) and b) why you would want to leave it on your kitchen bench for 10 days (answer: to ferment the flour so that its easier to digest).

Once I figured out that Herman was a sourdough starter, I started to investigate all the cake recipes for Herman and for sourdough starters in general.  I could have just made the recipe that came with Herman, but I really like chocolate cake, so of course I looked for something chocolate.  I based my cake on this recipe, but you know I can't stick to a recipe, so here's what I really did:

the finished product, to encourage you to keep reading...

1. the night before I made the cake I followed these instructions to feed Herman, instead of the instructions that came with him.  I honestly didn't want to make so much starter, so I didn't want to add 1 cup of flour AND 1 cup of sugar and 1 cup of milk and then have excess to give away, so I only used half a cup of flour and half a cup of flour, and I washed 1 cup of the starter down the sink first (I know!  I felt awful doing this!  but I gather that this is essential to make room for the fresh ingredients).
2. In the morning I combined 1 cup of the now very bubbly Herman, with 2 cups of organic white flour and 1 cup of raw milk. 
3. In the afternoon I then combined 1 cup of rapadura sugar, 1 cup of cocoa, 1.5 tsp of baking soda, 1 cup of coconut oil, a splash of vanilla essence and 2 eggs.  I then mixed in the starter mixture.  It was very think and difficult to mix, I didn't want to ruin it by mixing too much, so it ended up a bit of a marble cake :)
4. I then baked it in the Weber BBQ for about an hour at around 180degC until it seemed cooked
5. Served warm with natural yoghurt (I can never be bothered with icing), it was delicious!

Don't get me wrong, this cake is still full of sugar and not something you want to eat everyday, or bake every week, but that seems difficult to avoid if you're supposed to keep feeding and using Herman.  Fortunately, just like a sourdough bread starter, Herman will survive in the fridge or freezer for several weeks, until your next cake (or muffins, or pancakes etc).  You just need to get him out the night before you need him and feed him again (maybe even earlier if he's frozen), so that's he's ready to combine with your flour in the morning and ready to cook in the afternoon.

Traditionalists prefer to keep their starter in a glass jar with a muslin cover or in a ceramic crock.  Honestly, we have a massive ant problem in our kitchen at the moment, so I have been keeping my Herman in a plastic container with a lid that has a pop up thingy to release steam when you microwave (I actually bought it for aging cheese, which it is very good at too).  And I've had to keep it on the dining table away from the ants.  

I think I'll put some Herman in the freezer just in case I break the one I have at the moment, and I'll keep the rest out for the occasional cake experiment, until I get sick of it and then it can go in the fridge for a while.

So what do you think?  Do you have any personal experience with Herman?  Do you keep one yourself?