Starter hydration has an impact on how you maintain and use your sourdough culture. For example, the other day one wordpress commenter pointed out on my blogpost when is a sourdough starter ready that hydration impacts whether you can successfully use a float test – if for example you have a low hydration, stiff sourdough starter, it won’t float even when ready for use…which got me thinking about the impact of starter hydration. So I thought I’d explore the two common starter hydrations (liquid and stiff), as well as a third (somewhere in the middle) and try tease out the different aspects of their use.
- 125% hydration (i.e. a bit more water than flour, such as 100g flour and 125g water)
- Has the consistency of a runny batter (think pancake batter)
- One of the great things about a liquid starter is the micro-organisms (the yeasties and beasties) find it easy to get around in a liquid starter, which means it will typically be more active and quicker to achieve vibrancy than a stiffer starter.
- Therefore if your starter is struggling (in the early stages of life, or perhaps un-fed and unloved for a period!) increasing hydration is a good way to enliven a starter.
- A liquid starter favours acetic acid producing yeasties, so depending on when you use it it will typically a milder sour flavour than its less hydrated counterpart..
- This liquid hydration also makes it logistically easier for the baker to maintain – a liquid starter is pourable – so you can pour out to discard, and you can use a spoon to add and stir in new flour, with no messy hands. This suits a lot of bakers, and is perhaps why the liquid starter it is the most common starter hydration used in recipes – if in doubt, you can probably assume a liquid starter.
- 50-60% hydration (i.e. half the amount of water to flour, such as 100g flour and 50-60g water)
- Has the consistency of a stiff dough (think pastry dough)
- Now in contrast to the liquid starter, in a stiff starter the micro-organisms find it a bit harder to get around, which means it will typically be less active and achieve vibrancy at slower rate compared to its liquid brother. But this can actually be a useful trait to slow down your starter for storage at ambient temperatures, for example in a warm climate (not that I experience much of that in the Scottish highlands!).
- This hydration means messy hands when maintaining – as it’s more dough-like, you really need to get your hands in there to fully mix the flour and water when refreshing.
- A stiff starter favours lactic acid producing beasties, so depending on when you use it it will typically give a stronger sour flavour vs its liquid counterpart.
- Another point with a stiff starter, being non-pourable, is it’s advisable to break up the starter into smaller chunks when integrating into a production sourdough, so as to ensure good distribution and get the dough off to a good start.
- A stiff sourdough starter is by nature more transportable than its liquid brother (less chance of spillage!) – I like to think of our ancestors wrapping their stiff starter dough in a cloth and tucking into their breeches for a long journey!
Somewhere in the middle
- 90-100% hydration (i.e. near equal parts flour and water, such as 100g flour and 90/100g water)
- Has the consistency of a thick batter (think porridge)
- This is actually the starter hydration we err towards at doughies – you have the benefit of easy maintenance (as with the liquid starter), and yet the micro-organisms are slowed down a bit (like the stiff starter) which means it can be stored for longer (for us it will go two days between feeds at ambient temperature, albeit as we currently stay in a caravan that’s probably not that far off a fridge!)
Starter hydration can be easily morphed from “liquid” to “somewhere in the middle” to “stiff”. For example we would tend to morph towards a liquid levain in the run up to a weekly bake, from a somewhere in the middle hydration. If you want to experiment with this whilst keeping your original starter going, a great way is when maintaining your starter; simply take some discards, and then start a new starter at a different hydration by varying the flour and water quantities during refreshment.
…go get hydrating those starters! And don’t let the above ramblings mis-lead you into thinking sourdough starters are hard – it’s very easy to start and maintain a sourdough starter whatever the hydration; it’s just a simple skill and understanding we have mislaid in recent times. It’s time to get it back. (If you don’t believe me, go have a look at this refreshing post from the zero waste chef on “how to make a sourdough starter in stick drawings“.