You & Your Sourdough Starter: Relationship Advice & Maintenance Guide

After posting about how to create a starter, there were several questions about what to do next. How often do you feed it? How much? How can you tell if it’s healthy and ready? The truth is there are no prescriptive answers to these questions. You feed it when it’s hungry, and you give it as much food as you think it’s going to need before you use it or feed it again. And as to the 'healthy and ready', it tells you.

The thing about this whole sourdough affair is that it’s a relationship. It’s intimate, not transactional. If you truly want to know what your starter needs, then you have to pay attention to it. You have to use all of your senses to observe. In short, actively listen to it.

Listen with all your senses

When you stir it during a feeding, notice the consistency of it. At 100% hydration (equal parts flour and water) it should be the consistency of thick batter. Feel the resistance against the spoon. If your hands are clean then stick your finger in it and give it a little stir with your finger. Smell it and notice how the aroma at this point is ‘floury’.

Then give it another stir after an hour or so. You’ll be able to feel how it’s changed, and how the gluten has now developed a bit. How there’s now more resistance to stirring. It’s elastic. Smell it again. You’ll start to get yeasty notes from the fermentation that’s taking place. It might be a bit floral. Or fruity. Like fresh fruit that’s just on the turn, and has begun to ferment.

Observe it again after a few more hours. Has it doubled in size? More? Make a note of when it reaches peak height. How long does it stay there before it starts to fall again. How many bubbles can you see? Is it frothy? Give it a little taste and take in the aroma as you do it. Most of what we call flavour actually comes from olfaction; our sense of smell. And our olfactory sense is closely tied to memory. You probably won’t know that you know, but you’ll be storing memories away that will make sense later.

The aroma at or just after peak will be boozier. It may smell like beer or white wine or spirit but you’ll smell the alcohol at this point. And the more it ferments, the stronger it will smell. Give it another taste. Is it mildly acidic (sour)? What does it remind you of? Yoghurt? Buttermilk? Is it more sour than those?

Let it ferment longer, until it’s back down to it’s original level. Give it another stir at this point. Is there still any gluten strength (elasticity) left, or has it completely degraded? If it’s still a bit hard to stir then some of those gluten bonds are still intact. It will likely still smell boozy but may have moved over into smelling more like rubbing alcohol (surgical spirit). The taste is likely more acidic in a vinegary way, perhaps even with a slight metallic aftertaste. These are signs that it’s now out of balance and has begun to develop ‘acid load’.

The more it ferments, the lower the pH drops. Once the yeast have consumed most of the available food, the lactic acid bacteria begin to really do their thing. And while alcohol is the main byproduct of yeast fermentation, lactic and acetic acids are the main byproduct of lactic fermentation. Some acidity actually strengthens gluten, but eventually the falling pH completely breaks the gluten down, and the network holding it together collapses.

Interestingly, vigorously stirring the starter once it’s past peak will often cause it to peak again. The reason for this is two fold. First, the stirring unlocks more food for the yeast, sugars that they just couldn’t get to before. Second, adding oxygen actually flips the yeast from fermentation into another cycle called the Krebs cycle. Here they multiply exponentially so the yeast population will grow considerably in a matter of minutes.

At some point, the starter will exhaust available food and the gluten will completely break down. At this point stirring it is a bit like stirring really wet sand. The smell and taste will be sharp and unpleasant. This is hungry starter. Leave it longer and you’ll see a thin layer of liquid form on top of it after all the food has been consumed. This is called ‘hooch’ and is made up of alcohol, water and other fermentation byproducts. This starter is now very stressed. It’s neglected and starving. The yeast will be literally physically deformed from the stress if left like this too long. At this point starter often smells like acetone (nail polish remover).

Do not confuse resilience with happiness

The hooch will eventually turn grey, then black. It’s all fine, it’s just what happens to a starving starter with acid load, but they are incredibly resilient. In fact, the hooch protects the culture from contamination at this point. This is ‘survival mode’ so don’t confuse resilience with happiness. Letting it go this long between feedings weakens the starter over time, and at some point it’s going to be sluggish and will require more rehab time to get it going again. It may seem to just stop growing all of a sudden, but, in truth, these conditions will have been building over time.

You want the starter to smell fruity, yeasty, with an aroma closer to beer or white wine. It should taste mildly acidic, like yoghurt or buttermilk. This is a balanced culture. So based on all the memories you will be developing, learn to keep it in this state more than not. What seems strange and difficult to grasp at first will eventually become second nature if you put in the work and allow it to. These are the kinds of cues that will tell you the most about your starter health and current condition.

You’ll begin to learn that if you give it more food at a time (higher feed ratio) then it will take it longer to ripen, and will stay at peak for a longer period, but also tend to develop more overall acidity, but that lower ratios and feeding more often tend to actually keep it more balanced. If it’s been neglected then give it a few days of TLC with frequent refreshes at lower ratios. This will replace the yeast with new growth and new activity, and knock back the built-up acidity. If it hasn’t totally degraded and doesn’t have hooch yet, then 1-2 feeds might be enough to wake it up and get it happy again.

Listen to your starter, rather than any expert

Basically what I’m saying is listen to your starter, rather than any of us. It will guide you if you let it. There are no shortcuts here. If you truly want to learn to make exceptional bread this way then it will likely take you years. It took me two years before I was consistently baking what I would consider to be objectively good bread. And I didn’t start making great bread until I had baked probably 1000 loaves.

That’s not to say there won’t be some wonderful successes along the way. The stars occasionally align, and you’ll marvel at what you pull out of the oven. A few loaves later might also be a total fail. Learning any new skill is rarely linear, and that especially applies here. Simple, but not easy. Embrace both the joy of success and the disappointment of failure. You’ll see more of the latter in the early days. But if you keep listening to it, eventually it will come without any real conscious thought on your part. It will just innately be what you do to make beautiful bread.