Why we make sourdough donuts – and other science-y stuff

Staying at home and baking has been something a whole lot of people have been doing during the various stages of quarantine and stay-at-home and shelter in place in 2020.

And sourdough bread has trended across social media as many MANY people started to figure out how to wrangle with their own sourdough starters.

Lots of failures, many successes and surprisingly for me, not too many people exploring what else they could do with their sourdough.

Getting all hipster and baking bread with all the requisite steps of folding and resting and watching the clock and folding and… you get the idea.

The bread thing is quite the commitment.  There are definitely easier ‘no-knead’ methods and tutorials floating around, but I don’t have the patience for all of that.

We’ve been making sourdough donuts for a long time, and when we had the cafe we’d make a big batch of them every day. Our starter is called Mama Ru, and she’s a tricky mistress who needs daily attention.

We learned a LOT about how tricky and temperamental a sourdough starter could be but, once you find a rhythm and a recipe that works for you raised sourdough donuts are so much tastier than cake donuts or yeast donuts – they just are.

A donuts a donuts a donut – right?

Nope.

The donuts you grab when you’re in the foodcourt at the mall – the ‘buy a coffee get two cinnamon donuts free’ donuts – are cake donuts. Basically a cake batter with baking powder or baking soda used for lift. Moisture reacts with the baking powder and creates bubbles of carbon dioxide gas which are trapped as the tiny bubbles inside the donuts as it fries.

Raised or yeast donuts are made with a batter with bakers yeast used as the raising agent. The dried or compressed yeast is activated when it’s mixed with some warm water and fed with sugar. The yeast is alive – it’s a single cell fungi, and it feeds on carbohydrates, sugars and starches. As it feeds it produces carbon dioxide and alcohol – it’s the CO2 that makes the donuts rise.

Our sourdough starter also uses the power of yeast as the raising agent, but the yeast in a sourdough culture isn’t added or commercially produced.

Yeast spores occur naturally in the air around us, and many different yeasts occur in different places and in different proportions.

Sourdough cultures are an ancient process – there are just two ingredients, flour (the starch) and water – together with the naturally occurring airborne yeast spores.

A starter culture begins with a slurry of flour and water and given time the yeast settles on the flour water mix and begins to feed. Adding a little more flour and water to the starter everyday gives the slowly growing colony of yeast spores something to feed on. The yeast produces CO2 and continues to grow and replicate.

To keep the yeast alive, we feed Mama Ru every day.

So, WHY do we make sourdough donuts?

Flavour – the answer is easy.  There’s something about the subtle tang of the sourdough culture that is different to commercial bakers yeast. There’s a depth of flavour that we like.

There’s also some natural variation in every batch – even if the ingredients are exactly the same, the weather, humidity temperature have an effect of the dough and the donuts. The challenge and excitement of how things might turn out in 24 hours keep the process interesting.

To make our donuts, we take a dollop of starter, add the rest of the ingredients and mix the dough thoroughly. We set the dough aside for at least six hours (sometimes up to twelve if the weather is cool) and wait for the yeasty magic to happen.

This is when Mama Run gets a feed.

In the time set aside as the yeast feeds on the sugar and starch and ferments bubbles grow and the dough more than doubles in size. We give the box of dough a good bash on the bench to knock out some of the big bubbles and then the dough goes into the fridge overnight.

A full 24 hours later we’ll pull the dough out of the fridge, give it gentle knead and roll it out about 2cm thick. We use a cutter to shape the donuts and then we wait again – probably 30 minutes until the donuts gently start to rise again.

We give them a final stretch and twist and then it’s into the fryer. Bubbling away at 180 degrees the donuts sink to the bottom at first and then pop to the surface floating in the boiling oil. A quick flip and the donuts are cooked on both sides.

Rolling in the sugar while they are still piping hot out of the oil ensures a good coating of sweet cinnamon goodness sticks to the surface.