Learn the science behind:
Ever been to a donut shop with only five types of donuts? I definitely haven’t. Most donut shops excel in giving you choice overload. Way too many variations to choose from. But, if you look more closely, you will see that most vary in their flavour combinations (that is, the icings or fillings) and not the texture and consistency of a donut (that is, the donut underneath that sugar layer). Which is interesting, since there are so many different types. You’ve got your basic cake or yeast donuts, you can use water roux, or, as we discuss here, sourdough, to make your donut.
Sourdough donuts are a bit sturdier than your regular donut. They have some more bite. Also, their flavour is different, though it is hard to describe, but it definitely is less overly sweet. They are still light fried dough balls of course, but set you apart from the crowd.
A quick re-cap on donuts
There’s no need to give you a full introduction on donuts again. We’ve done that several times on the website already. Introducing you to the history of donuts and explaining both cake & yeast donuts. In short, donuts are fried pieces of dough, often shaped in a ring (but not always).
You want the donut to puff up in the fryer and have a lot of air bubbles inside to make sure it doesn’t turn out too dense. There are roughly two ways to do that, either you add baking powder or baking soda which will react to form gas as soon as the dough hits the oil, or you can add yeast. Yeast is slower, it is a living micro organism and needs time to produce those gas bubbles that will aerate your donut.
What are sourdough donuts?
Sourdough donuts are actually very similar to yeast donuts. Both are made with a dough that needs to be proofed, to give the yeast a chance to do its job. However, in yeast donuts you just add the yeast to the dough whereas for a sourdough donut you need sourdough starter to introduce those micro organisms.
Sourdough starter is a mix of water and flour that is full with useful bacteria and yeasts. These micro organisms develop flavours as they grow, but also acidity (hence the name sour) and gas bubbles to aerate your dough. A sourdough starter will give your donut a different flavour, but needs more time to do its work than regular yeast.
Making a sourdough starter
Making a sourdough starter takes time, at least a week, but it may also take you longer. We’ve discussed how to make a sourdough starter more extensively before, but here’s a quick overview.
You start by mixing equal quantities of flour and water. You need the flour because it is the food for the micro organisms, you need the water because they won’t grow on dry flour. There are a lot of micro organisms, including yeasts, in the air around us, so you could just leave it on the countertop and wait for the micro organisms to enter you mixture and start growing.
However, this is often tricky, therefore you want to add a source of these micro organisms. A commonly used source are raisins for instance, they contain a lot of sugar, which is food for the yeasts and bacteria and naturally contain yeasts on their surface. It is now a matter of waiting for the micro organisms to start growing. You will see that they are active once bubbles show up in your mixture.
From this point onwards you need to refresh the starter a few times. You do this by pouring out most of the starter and adding new flour and water. This is to make the starter more sturdy.
Unique sourdough donuts
Every sourdough starter is different. Every starter will have a different composition of micro organisms. This composition depends on your location, the climate, the weather, etc. Even if you take your starter and move to a different part of the world it will change over time, adjusting to its new environment. As a result, your sourdough donuts will be unique!
What makes sourdough donuts different?
You need patience to make sourdough donuts. The dough for a sourdough donut needs to proof for a couple of hours, compared to no proofing time for cake donuts or maybe an hour or two for yeast donuts. The reason for this long time is to ensure the micro organisms prosper. They aren’t as readily active as the yeast you buy in the supermarket.
During this time all those micro organisms from your sourdough starter that are part of the dough will grow and live. They create gas bubbles (carbon dioxide) but along the way they also produce all sorts of flavour molecules. This is what gives sourdough donuts a depth of flavour that other donuts don’t have (very similar to comparing a sourdough bread vs. a regular one). It doesn’t mean though that sourdough donuts are sour, although if you want, you could make them turn out sour.
But it’s not just the flavour components. Because the dough has had such a long time to proof, other chnages occur. You will have more gluten formation, resulting in a sturdier structure. Also, some of the starches in the flour will break down into smaller molecules, given a smoother, stretchier dough. You create some softness that is comparable to the effects of using a water roux.
Sourdough donut recipe
If you’re like me and like a sturdier, firmer, flavourful donut (even without icing), instead of a very light and fluffy one, this is the one to try.
Of course, now that you have yet another base to vary with, the chances for choice overload in your donut shop increase even more. Just imagine all the toppings and fillings that work well for your newly created sourdough donut. That said, I would say it’s worth it.
If you’re looking for proper instructions on how to make the sourdough starter to make this recipe, have a look at the post fully dedicated on the topic of sourdough starters.
Want to learn more on how to fry foods best? Have a look at my post on frying, in which we use ‘oliebollen’ as an example, but it also goes up for donuts.