Starter Preparation for baking

The way you prepare your starter for baking can have a significant impact on your loaves.  The most common approaches are:

Unfed Starter (Countertop) – Using an unfed starter that has been at room temperature is the least desirable method of preparing your starter for baking.  If your starter has risen and fallen since the last feeding and is at room temperature, you can use it to make bread, but it usually has a high acid load and suboptimal yeast population.  This will typically result in a slow, unpredictable rise and the high acid load can increase the risk of premature overproofing of the dough.

Unfed Starter (Refrigerator) – Using an unfed starter from the refrigerator can produce a wide range of results.  It depends how long the starter has been in the refrigerator since the previous feeding.  For example, assume you do a 1:2:2 feeding of your starter and refrigerate it on Monday.  If you use that starter on Tuesday, it will actually be somewhat weak because it is still diluted from the previous feeding and has likely not recovered the full yeast population. Because you discard 80% of your previous starter with a 1:2:2 feeding ratio, your starter needs to increase its yeast population by 400%, or four times, just to return to parity with the starter population before discarding.  Using diluted starter such as this has the same effect as using a lower inoculation percentage (the percentage of starter relative to flour weight) in your recipe.  If a recipe calls for 20% starter and you used a 1:2:2 starter immediately after feeding, it is exactly the same as using 4% starter in the recipe (one fifth of recommended amount).  Refrigerated starters usually do not visibly rise and fall but you can tell how far along the starter is by smelling it, stirring it, and looking for hooch to develop on the top.

If a starter has been in the refrigerator for 1 week, it may actually be quite strong when using it directly in a recipe. After about 1 week in the refrigerator, the starter has likely consumed all of the food from the previous 1:2:2 feeding, but it not yet starving.  You can tell if a starter is starving because it will start to develop hooch (clear alcohol) on the top. If your starter has a thin layer of hooch on the top, in the fridge, it is just past peak starter population and is still pretty strong for use in baking.

If your starter has been in the refrigerator for two weeks or more, it is likely starving as evidenced by an increasing layer of hooch on the top.  This type of starter has a suboptimal yeast population and is starting to become quite acidic. You can still use this type of starter for baking, but it will have lower, unpredictable rising power and a higher acid load, which can lead to premature overproofing.

Some popular videos demonstrate using very old starter from the fridge (e.g., five months since previous feeding).  These will typically rise a loaf but can take a very long time to work.  Using a very old, unfed starter is similar to just using a smaller percentage of starter in your mix.

Recently Fed Starter – Low Feeding Ratio

You can give your starter a 1:1:1 feeding and use it in a recipe. After feeding, wait for the starter to peak and add it to your mix.  This works perfectly fine, but it can carry over a fairly high acid load because of the large percentage (33%) of retained starter. 

Recently Fed Starter – High Feeding Ratio

You can feed your starter 1:2:2 or even up to 1:5:5, wait for it to peak and then use it in your recipe.  This method is recommended.  It catches the yeast population at peak and it de-acidifies the starter by using a very small carry-over portion (20% in 1:2:2 and 9% in 1:5:5).  A starter with a large yeast population and small lactic acid bacteria population is desirable.

Leaven

A leaven is an “offshoot” of your starter created specifically for a batch of dough.  There are three reasons to create a leaven.

• Quantity – Many people do not keep a large quantity of starter so they need to bulk up their starter quantity for baking. A typical example is keeping 90g of starter for daily maintenance, but a recipe calls for 200g of starter for a recipe.  Here are different ways to build a leaven (an offshoot of your starter) to reach that quantity.

1:1:1 leaven build with 67g starter, 67g flour, 67g water

1:2:2 leaven build with 40g starter, 80g flour, 80g water

1:5:5 leaven build with 20g starter, 90g flour, 90g water

1:10:10 leaven build with 10g starter, 95g flour and 95g water

• Rise Time and Acidity

Using the feeding ratio examples above, the higher feeding percentages will take longer to rise and peak, and will generally have a lower acid load because of the lower percentage of carryover starter.  You would use a high feeding ratio, for example, if you want your leaven to rise overnight where a lower feeding ratio would peak too quickly.  You would also use a higher feeding ratio if you want to de-acidify your starter.  This is also sometimes referred to as a “young, ripe” starter (a la Tartine method).

• Different Flour Mix

In general, you can use any starter to make any type of bread.  You do not need to match the type of flour in your starter/leaven to the starter in your recipe.  There are a few exceptions to this general rule. The most common example is when bakers keep a rye starter, but plan to make a non-rye loaf.  In this case, you would not simply bulk up your rye starter with rye flour because you would be adding a significant amount of rye to a white loaf, for example.  In this case you would create a leaven (an offshoot of the primary rye starter) but you would feed it with the type of flour you are planning to use in your loaf (e.g., bread flour and whole wheat).  This is really a matter of preference because it primarily impacts the flavor of the loaf, not the mechanics of the recipe.

A leaven is an “offshoot” of your starter created specifically for a batch of dough.  There are three reasons to create a leaven.

• Quantity – Many people do not keep a large quantity of starter so they need to bulk up their starter quantity for baking. A typical example is keeping 90g of starter for daily maintenance, but a recipe calls for 200g of starter for a recipe.  Here are a different ways to build a leaven (an offshoot of your starter) to reach that quantity.

1:1:1 leaven build with 67g starter, 67g flour, 67g water

1:2:2 leaven build with 40g starter, 80g flour, 80g water

1:5:5 leaven build with 20g starter, 90g flour, 90g water

1:10:10 leaven build with 10g starter, 95g flour and 95g water

• Rise Time and Acidity

Using the feeding ratio examples above, the higher feeding percentages will take longer to rise and peak, and will generally have a lower acid load because of the lower percentage of carryover starter.  You would use a high feeding ratio, for example, if you want your leaven to rise overnight where a lower feeding ratio would peak to quickly.  You would also use a higher feeding ratio if you want to de-acidify your starter.  This is also sometimes referred to as a “young, ripe” starter (a la Tartine method).

• Different Flour Mix

In general, you can use any starter to make any type of bread.  You do not need to match the type of flour in your starter/leaven to the starter in your recipe.  There are a few exceptions to this general rule. The most common example is when bakers keep a rye starter, but plan to make a non-rye loaf.  In this case, you would not simply bulk up your rye starter with rye flour because you would be adding a significant amount of rye to a white loaf, for example.  In this case you would create a leaven (an offshoot of the primary rye starter) but you would feed it with the type of flour you are planning to use in your loaf (e.g., bread flour and whole wheat).  This is really a matter of preference because it primarily impacts the flavor of the loaf, not the mechanics of the recipe.

Yes.  However, a leaven (or offshoot batch of starter), will almost always have a lower acidity level than your starter — and lower acidity is preferable. 

A leaven typically has lower acidity than your starter because it is usually made with a large feeding ratio (1:5:5 to 1:10:10) and the leaven is typically used in the recipe before it peaks.  These two factors reduce the acidity level. 

I prefer a low-acid starter/leaven, especially when baking in warm weather, because it reduces the chances of overproofing, and it allows the yeast to be more productive.  

See examples under the FAQ “Starter Preparation – Basics” of why you may want to create a leaven.

You have a fairly broad window of time to use your starter in your recipe.  Here are some considerations: 

1. Pre-peak: If you mix up your starter/leaven and it has not yet peaked, you can use it in your recipe, but it will not be as strong as a starter/leaven that has already peaked.  So, if your recipe calls for 20% leaven and you use a pre-peak leaven, it may be the equivalent of using 15% because it has not yet reached full strength.  It will work, but it may take longer than expected to ferment and proof because you are effectively using less starter in this example. 
2. At Peak: Many recipes call for using your fed starter/leaven as soon as it peaks.  This is a good practice and works well.  You can tell when you starter is peaking because it will be domed on top.  As soon as the dome begins to fall, the starter is just passing “peak.”  It is not necessary to catch it at the moment it peaks.  There is about a one-hour window around “the peak.” 
3. Slightly past peak – If your starter has domed and is beginning to fall, it is still super strong.  In my opinion, I still consider a starter just past peak height to still be at peak strength.  Some studies show that the yeast population is actually at its apex slightly after the starter reaches peak height.  There is probably a one-hour window post-peak, where the starter may be at its strongest. 
4. Past-Peak and Falling: If your starter/leaven is past-peak and is beginning to fall in height, it is beyond the optimal point to use it for baking, but it will still work.  The only thing to consider is that once a starter peaks, it starts to become more acidic as it falls.  High acidity levels can accelerate over-proofing due to gluten deterioration, and this issue is exacerbated by warm temperatures.  If I am baking on a very warm day, I always try to use my starter pre-peak (low acidity), versus post-peak and falling (high acidity), to reduce the likelihood of overproofing. 

When preparing your starter for baking, it is usually recommended to catch the starter at or near-peak when adding it to the mix.  Using a starter pre-peak is often referred to as a “young/ripe” starter (a la Tartine).  This will generally be a very low acidity, mild starter/leaven.  Using a slightly post peak works fine. This is actually the point where the yeast population is at its highest.  

Using a starter well past peak will have suboptimal performance and it will start to be more acidic, but can still raise a loaf – perhaps just more slowly or unpredictably.

You do not need to catch your starter exactly at peak to use it for baking.  At room temperature of 72F/22C, your starter can safely go an hour or two past peak and still be perfectly strong to use for baking.  If your starter is very acidic or your starter temperature is very warm (90F/32C), then every minute past peak substantially increases the acidity level of your starter which can slow down your yeast production and lead to premature overproofing.

Your starter is still strong and perfectly usable for baking for a few hours after it peaks.  The starter/leaven will start to flatten on top, but if it is not visibly falling, it is still strong and ready for baking. 

If you need to delay your mixing by more than a few hours, put your starter in the refrigerator (preferably right before it peaks).  You can keep a “peaked” starter in the refrigerator for about 12 hours (sometimes more), and still use it directly in your mix.  You do not need to let it come up to room temperature.   

If your starter is well past peak (a few hours) and visibly falling, you can give it a “refresh” feeding to reactivate it.  In this case, I usually give it a top-off feeding of 30-50g of flour and 30-50g of water and let it rise again.  This is known as a “refresh” and is a perfectly acceptable way to manage your starter peak to synchronize with your baking schedule.  

If you do multiple “refreshes” your starter can start to become more acidic.  But one refresh buys you a few hours and is usually sufficient for most schedule modifications. 

The “Float Test” is a test of starter readiness popularized in Chad Robertson’s “Tartine Bread.” There is a great controversy about the test because many people have “proven” that the test is unreliable.

Here is the bottom line.  If you follow the starter/leaven preparation steps recommended in the Tartine book/recipe, then the float test is a reliable indicator of starter readiness.  If you do not follow that recipe and process, the test is less reliable. 

It can be an unreliable test because there are many ways that a perfectly strong starter can fail the float test, including:

• Higher hydration starters are less likely to float
• Starters made with different flours (e.g., rye) may be perfectly strong but will not float
• Starter may be past peak but still perfectly capable of rising a loaf (albeit more slowly)
• If you stir a perfectly strong starter, you can cause it to sink in the float test

For these reasons, a “strong” starter may fail the float test, and a weak starter will always fail the float test.  This is the reason for great debate on this topic. It is a weak test with somewhat ambiguous results if your starter “fails” the test. 

Experienced bakers are aware of the reasons a starter may fail the float test (see above). Use your judgement.  If your starter has not yet peaked and it fails the float test it is probably not ready. 

The float test is a valuable data point if you are following the Tartine recipe and process. If you follow that process and your starter floats, it is hard to argue that the starter is not ready.  But there are plenty of reasons why a starter may fail the test and still be ready to rise a loaf. 

It’s complicated.  It depends how long it was in the refrigerator, how much it was fed prior to going into the fridge, and how the starter looks when it comes out of the fridge.  Here are a few examples: 

1. Recently fed – If you fed you starter 1:2:2, for example, and put it in the refrigerator for about 1 week, it may still rise when you take it out of the fridge and bring it back up to room temp.  If it rises, this means there was still unconsumed food left in the starter and it is just like feeding a starter after taking it out of the fridge.  If it rises after coming to room temperature, I’d use that for baking. 
2. Very recently fed – If you fed your starter 1:5:5, for example, and put it in the refrigerator, then came back the next morning and tried to use that starter in a recipe, it would still be very diluted from the prior feeding.  It would work, but if your recipe called for 20% leaven, using a diluted starter would be the equivalent of only using 4-5% leaven in the recipe. 
3. Fed a long time ago – some people keep their starter in the fridge, unfed for as long as one month (or longer).  If you take this starter out of the fridge, look at the top of the starter. If it is still cream-colored and has no liquid on top, it may still be strong but this is highly unlikely after one month.  If it is covered with a thin layer of clear liquid (hooch), it may still be strong but should be refreshed with a few feedings before using it for baking.  If it is covered with dark gray hooch, it may take a few more feedings to refresh it.  But these starters usually still have a strong yeast population and are fairly easy to recover. 

The Bottom Line: It is impossible to give a “yes” or “no” answer to this question.  When people simply say, “I use my starter straight from the fridge,” this could mean so many different things as illustrated above.  Learn to “read” your starter and do a few experiments with your refrigerated starter.  In general, it is impossible to kill your starter in the refrigerator (unless it gets moldy), but it can behave quite differently coming out of the fridge depending on how much food remains uneaten.  

Consult the video below from Full Proof Baking for a great example of how to refresh and strengthen your starter after it comes out of the refrigerator.  

Warmer temperatures create a more acidic starter.  There are two types of acid-forming bacteria in your starter.  Your starter will produce more acetic acid (i.e., vinegary) at lower temperatures (typically below 80F/28C).  At higher temperatures (above 80F/28C) your starter will favor more production of lactic acid which produces are more yogurt-flavored, mellow, tangy flavor.  

Never let your starter temperature get above 90F/32C when preparing your starter for baking. At that temperature, the protease enzyme is stimulated, and it will begin producing gluten-destroying enzymes. 

Some beginners (myself included) attempt to speed up their starter or leaven creation by warming it up.  This can lead to disastrous outcomes with rapidly overproofing dough.   

Many people keep their starter in the refrigerator, and at that temperature (37F/3C) the microbial activity is significantly slowed.  Some studies recommend maintaining your starter at 55F/13C at all times.  If you have a wine refrigerator, this is a common temperature setting.  Your starter may benefit from being kept at a temperature warmer than refrigerator temperature, but cooler than room temperature.  

The best way to control the timing of your starter’s peak is to control the temperature.  Try to find a cooler location in your home to slow down the rise.  

If you do not have another option you can put your starter “on ice.” 

Put Your Starter On Ice

1. In the morning, feed your starter/leaven
2. Put your starter/leaven jar in a bowl of ice
3. The ice take about four hours to melt and will delay the start of the fermentation

This method is the equivalent of feeding your starter about four hours later.   Depending on the temperature of your home, you may need to use more or less ice to keep it cool for the desired amount of time.  With a little practice, this method really works. 

For refrigerator maintenance, you have a few options:

The “Feed and Deplete” option

In this method, you would feed your starter (for example, 50g carryover starter, 50g flour and 50g water), a 1:1:1 feeding ratio, let it begin to rise and put that in the fridge. 

When you are planning to bake, take a spoonful of that starter out (10 to 20g) and use that to create a leaven to bulk up the quantity you need for baking. 

When your “mother” starter in the refrigerator nears depletion, take it out and refeed it back up to the 150g quantity. 

With this method, because you are using such a small amount of your starter, you can leave your starter in the refrigerator for a few weeks before needing to refresh it.

“Fridge-ready” option

With this method, you prepare your starter with enough quantity for what you may need for baking (and some leftover).  For example, if you normally need 200g of starter for your recipe, you would feed your starter 80g carryover, 80g flour and 80g water to create 240g of starter.  Put that in the refrigerator.  When you are ready to bake, pull the amount you need from your starter (e.g., 200g) and refeed the remaining amount with 100g flour and 100g water to replenish the amount you need.

With this method, you generally want to use your starter within 7 days of feeding it, and your starter is not in optimal condition.  It can be weaker than expected in the early days, and more acidic than optimal in the latter days.  But it generally works if you are not too concerned about perfection.

“Fridge hold” option

In this method, you basically prepare the starter you want to use in your dough, at room temperature, and as it is approaching peak, you put it in the refrigerator to put it “on hold.”  You can usually keep it in the refrigerator for about 12 hours and it will still be in pretty good shape to use in your dough.