An experiment in making a sourdough version of
Tiger Loaf aka Marco Polo, Giraffe or Dutch Crunch Bread.

Most of us have our own favoured breads or other leavened baked goods. These days they are generally baked using commercial yeast and the most readily available recipes use a commercial yeast process; sourdough versions can be far more difficult to find.

Attitudes are changing

More recently, for one reason or another, perhaps health, more flavourful bakes, or simply a yearning to get back to ‘the old ways’, an increasing number of people want to enjoy those same baked goodies without the use of commercial yeast.  More are baking at home, and there are artisan bakeries springing up all over the place.

The good news is, with a little work and some trial and error, you can convert any recipe which uses commercial yeast into one which only uses wild leaven – aka your own sourdough starter.

The Unpredictability Challenges

The exact commercial yeast to sourdough starter conversion ratios seems to vary – entirely unsurprising when you factor in that starter strengths and environmental conditions can vary greatly.  This is probably why commercial dried and fresh yeast became so widely used in the first place – they are far more predictable and stable as far as working out timings and therefore achieve more consistent results.  But let’s face it, that’s what we all love about baking with sourdough, the unpredictability, the fact that the results depend on range of factors including how strong and healthy our starter is, and how well we can change and adapt the process on almost every bake to contend with changes in temperature, flour and water, time restrictions, and more.

With all of this in mind, I embarked on trying to recreate that old supermarket favourite — the Tiger Loaf aka Marco Polo, Dutch Crunch or Giraffe Bread— taking a yeasted recipe and converting it to a sourdough recipe.

This is the Original Commercial Yeast Recipe (60% hydration):

Ingredients

Bread Dough
– 500 g Strong White Bread Flour
– 7 g Dry Instant Yeast
– 1½ tsp Golden Caster Sugar
– 1½ tsp Salt
– 15g/1 tbsp room temperature butter
– 300 ml warm water (225ml cold, 75ml boiling)

Paste Topping
– 2 tsp yeast
– 90 ml warm water (60ml cold + 30ml boiling)
– 1.5 tsp sugar
– 2 tsp toasted sesame seed oil
– 75g rice flour

Method

1. Mix flour, yeast, sugar and salt in a big bowl. Use fingertips to rub in the butter until it resembles fine breadcrumbs.  Mix in the water with a knife.
2. Tip dough onto a lightly flour-dusted surface and knead for 10 minutes (or use the dough hook attachment on your mixer)
3. Lightly oil your mixing bowl and place the dough in it and cover the bowl with a clean tea towel. Leave to rise until almost doubled in size.
4. Once risen, gently kneading the dough just 5 times. Shape into a smooth oval and sit on a floured baking sheet.
5. Cover the dough with a clean tea towel and leave to prove until almost doubled in size again.
6. Preheat your oven to 200°C (fan 180°C, gas mark 6). Whisk all of the topping ingredients together until smooth. Leave this to rest for 10 minutes.
7. Spread the paste all over the top and sides of your loaf with a palette knife
8. Bake for 35 minutes, until golden brown and crackled. When you tap the base it sounds hollow.
9. Cool on a wire rack.

The Conversion

Two things to keep in mind:

1. It’s important to remember that if you substitute Starter for commercial yeast, you must also alter the flour and water quantities in the recipe in order that the recipes hydration remains the same.  Having a Starter @100% hydration makes this calculation easier.
2. The whole baking process must change to accommodate the longer fermentation times. Basically, follow the usual sourdough process: mix, stretch and folds, bulk ferment, second prove, bake.

These are the generally accepted conversions:

Using this basic conversion theory, I substituted the 7gms of commercial yeast for 100g sourdough starter @100% hydration, an inoculation of 20% in Baker’s percentages, and then made the changes to the flour and water quantities in the basic recipe.

By adding 100 g of Starter (made of 50ml of water and 50g of flour) I needed to deduct 50g of flour and 50ml of water from the original quantities in the recipe, so keeping the dough hydration level the same.  So, the recipe changed as follows, note that the hydration has remained the same.
Start of a new sourdough Bread Dough recipe  (60% hydration):
– 450g Strong White Bread Flour
– 7gms Dry Instant Yeast
– 100 g Active 100% hydration starter
– 1½ tsp Golden Caster Sugar
– 1½ tsp Salt
– 15g/1tbsp Butter (softened)
– 250 ml warm water (225ml cold, 75ml boiling)

20% starter is a fairly standard starter ratio, but if you wanted to do a longer prove or extend the process you can reduce the amount of starter; just remember to make the corresponding changes in the recipe flour and water quantities.

As always, the important thing is to WATCH YOUR DOUGH throughout the process, and only use the timings as a rough guide.

For the topping, I don’t think I swapped in enough starter for my original experiment, I only used 2  tsp. The bowl in the left one is the original commercial yeast topping recipe, the one on the right used starter and was slightly thinner consistency. The sourdough one resulted in the very light golden crust, I have adapted the recipe to having more starter so will see how this goes on the next try. Adjust the water to suit, you may not even need it as the starter may have enough, basically the topping should be a fairly thick, but spreadable paste.

Paste Topping
– 2 tsp yeast
– 85 g starter
– 1.5 tsp sugar
– 2 tsp toasted sesame seed oil
– 75g rice flour

As I mentioned above, any conversion recipe will involve some trial and error, but it is all good fun and you are developing a whole new recipe exactly to your own taste and which you can share and continue to use for years to come. The more conversions you do, the better you will get at it.

Check out the final Sourdough Tiger Loaf recipe and give it a try for yourself.