To Feed The Ferment
When the sourdough starter needs feeding take out half of the weight of sourdough from the container, and top it back up by adding in at least double the amount of fresh flour and warm water you take out – this is why the sourdough is also ‘refreshed’ and the sourness and acidity reduced. Adding in double the fresh flour to a smaller portion of ferment dillutes both the yeast colonies and the bacteria colonies (which is a good thing – see the important note below).
It also takes longer for the bacteria to multiply and start making acidic compounds than it does for the yeast to multiply – as a guide, after 3 days in a warm room the bacteria (and therefore the acidic sourness) returns in full. This is why by controlling the timings of ‘feeding’ and ‘refreshing’ the ferment (before using it to make bread) you can control the sourness of your bread.
In our recipe (for the first feeding) remove about half the ferment dough, 200g, and replace it with 400g of your chosen fresh bread flour and about 250ml of warm water, (and if used add in some extra honey 1 tbsp etc. used to feed/flavour the dough) and thoroughly mix it in to (re)make a moist dough. Leave it for an hour, give it a mix, add a little more water if it needs it, then place it back in the fridge.
The removed 200g of sourdough starter can be used to make bread with.
A Fridge Full Of Ferment
- The accepted ‘rule’ is: at each ‘feeding’ you need to remove half and then replace with double.
This means that over time your sourdough starter will grow in size, from 400g to 600g to 900g etc. making a fridge full of ferment over time …in the fourth feeding you will have created a sourdough starter which is 1.2Kg …
This is fine in a commercial artisan bakery, but not for the home, keeping the ferment in the fridge will slow this process down (less ‘feedings’) meaning you can slow down the rate at which the sourdough starter grows in size.
You can of course also keep going back to ‘square one’ each time, always start with just 100g of sourdough ferment remaining from the original batch, with 200g of fresh flour and 150ml of warm water added in – this will always keep your sourdough starter at around 300g in weight – and removing 200g at each feeding also means it is the perfect amount removed to make one large loaf of sourdough bread once a week.
Important Note: You must always double with fresh ingredients (and many artisan bakers triple) what is left in older sourdough ferment, never replace like for like or the ‘sourness’ from the acids will be too strong and the gluten in the ferment will become broken down – essentially the starter will become ‘weak’ and ‘vinegary’ and will no longer make ‘clean tasting’ bread. The surplus sourdough taken out of the ferment can be used to make bread, be disposed of on a compost heap for the garden, given to friends to start their own sourdough ferment, or be used to make a ‘dry’ sourdough starter by baking it in a low oven and drying it out whilst keeping the yeast alive and dormant.
Using The Sourdough Starter
Traditionally, a certain amount of yeast rich sourdough starter (somewhere around 30% on average, depending on the yeast and water content of the starter dough) is mixed into the main bread dough.
Take 200g of the sourdough ferment and add it to a ready made bread dough mix of 600g of bread flour and 450ml of warm water. Note: The 800g of bread dough, (made from the 200g of sourdough ferment and the 600g of fresh dough) should, after kneading, become a traditional silky, elastic and smooth bread dough – so as in traditional bread making add more or less water/flour to achive this.
To get the bread dough smooth and elastic it should be gently kneaded on a floured work surface for about 10 minutes – left for an hour covered, then gently kneaded for another 5 minutes. It is then formed into a ball and left in a floured bowl (or proving basket) in a warm room (20C) covered with a clean cloth and allowed to rise as normal as the yeast cultures multiply and produce carbon dioxide gas.
The process is largely similar to using a pure strain of active Baker’s yeast, although some care must be taken since the rise time of most sourdough starters is usually somewhat longer than the average for typical Baker’s yeasts – approx 12 to 16 hours.
The sourdough, having fully risen after 12 to 16 hours, is then ready to bake into bread in your usual fashion.
General Keeping Advice:
Yeast likes Food, Air, Warmth, Water. Take care of these 4 things and wild yeast is very robust – once you have a culture of wild yeast growing in your dough you can easily keep the colony alive – chill in the fridge to slow the processes down.
Wet dough initially ferments better than a dry dough, so at the start keep the sourdough moist at all times in a small bowl or open wide-necked glass or plastic jar (avoid metals).
When you want to rapidly grow your wild yeast colony keep the dough in a warm room, and it is initially important to keep the dough open to the air until wild yeast cultures grow.
Once established feed the sourdough when it stops ‘bubling’, (if a wet batter) or rising, (if it is more of a stiff dough) about once every 24 to 36 hours, or keep it in the fridge to slow down the fermentation process, it will need feeding less often, every 5 to 7 days.
Disposing of the extra sourdough not used: If you are feeding the starter, without using it to make bread, then every time you feed it you will be removing about half of the dough to replace with double fresh flour and water. This surplus dough can be used to make a ‘dry’ sourdough starter.
Once a month, completely remove the sourdough from its container. Wash the container (or make a new cheap plastic one cut down from a water bottle) in hot soapy water, then rinse the container thoroughly with clean water and leave to dry. Remove half the ‘starter’ then put the other half back in the container and ‘feed’ it fresh flour and warm water. Some bakers have kept a sourdough starter like this for decades.
Frequently Asked Questions:
1. Should the intial dough of flour and water be quite wet to start off the yeast cultures? Yes, even a thick batter is fine. The liquid on the surface will start to bubble up and froth with the growth of yeast in the batter after two days (when kept somewhere warm and open to the air). You can then firm this dough up by adding in double the amount of fresh flour with less warm water. Note: Some bakers like to work with a firm starter dough, others like to keep the starter dough very wet and runny, (called a ‘wet sponge’) – its your choice. Drier starter doughs can be more acidic and ‘sour’ than wet ones.
2. Should the sourdough be any particular colour? No. Depending on all the changeable variables of flour type, water and air quality etc. each sourdough starter will have its own shade, from cream to brown. If the dough is ‘wet’ a light brown ‘beery’ appearence in the liquid on the surface is quite usual because of fermentation – when a stiffer dough is used it will usually take on a ‘buttery’ colour. Cream to light brown is normally fine.
3. Are there any signs to look out for to tell if the sourdough has gone off? The fermentation process carried out by the yeast usually makes the growth of ‘bad’ bacteria very limited, as does the acidic compounds made by the ‘good’ bacteria. However if the yeast runs out of food, (the dough is not refreshed) and the yeast cannot continue the fermentation process, bad bacteria can multiply. The dough can shrink, toughen up, and darken in colour from green to black; it will also smell like gone off milk; all bad signs. This happens more rapidly in warm conditions.
4. What are the ‘good’ and ‘bad’ smells to look out for? If the yeast rich sourdough starter (ferment or barm) smells of beer this is a good sign of yeast production, if it smells of beer and a little bit like vinegar you probably have the perfect sourdough for making bread with, if it smells just of vinegar the acids are dominating and the bread will be very sour and the ferment needs to be fed and refreshed with double (or tripple) fresh ingredients.
5. What is a good structure to look out for? It depends if you are taking about a drier sourdough starter or a wetter one. Wetter doughs will tend to have a frothy bubbly top, with a structure like a wet sponge underneath, drier doughs tend to have a firmer ‘cheese-like’ surface with a honeycomb structure beneath.
6. When is it best to use a starter dough? I find it is best to use a starter dough (made from scratch) on the thrid or fourth day after leaving the dough out in a warm, well ventilated room – however, when using an already established starter sourdough from the fridge I like to use it 24 hours after I have fed and refreshed it.