Baked Grains - A study in baking with grains

Breads and Sourdough Breads

Category: Sourdough Starters

Things to consider when feeding your starter

Feeding your starter
There are five main factors that you control in how you maintain your starter.

1. Ratio of starter:flour:water (by weight)
The amount of starter (as a percentage of the new starter weight can vary from 5-50%.
Some examples of feeding regimens for a starter size of ~120g. All assume 100% hydration:
5% feed:
6g starter : 57g flour : 57g water
20% feed:
24g starter : 48g flour : 48g water
33.3% feed
40g starter : 40g flour : 40g water
50% feed:
60g starter : 30g flour: 30g water
The lower the % of starter, the less acidic (sour) the starter will be. Using low %s of starter is also known as “sweetening the starter”.
Since flour is the starter’s food source – it is easy to see that the ratio of flour to starter increases significantly as the starter % decreases.
At 5% the ratio is 9.5 to 1. At 50% the ratio is only 0.5 to 1. The starter will have 10x the food supply with a 5% feeding vs a 50% feeding. It will go much longer between feedings. It will also ferment more slowly as the yeast and bacteria populations are significantly reduced with respect to the overall starter.

2. Hydration level
A starter can vary in hydration between 50-200%. The hydration level will directly affect what you should expect to see after feeding. 100% is likely the most common hydration (equal weights of flour and water). If the starter is at 100% it lower hydration and is being fed with a wheat flour, the starter will have a gluten structure (just like any other bread dough). The starter will go through a lull period and then begin to rise. It will increase in volume until it reaches a peak. The increase in volume is partially based on the starter’s health – but mostly indicates the gluten strength of the flour being used during feeding. It will hold a peak for some time (longer for higher gluten flours) and if left – will eventually collapse. For higher hydrations, the gluten will not be strong enough to trap the gas produced – the starter will not increase in volume – but will have a period of active bubbles rising to the top and popping. This activity will eventually slow.
Higher hydrations will:
Ferment faster
Run out of food sooner
Produce lactic acids rather than acetic acids

3. Temperature
Temperature can be varied from 40f to 85f. It is not advisable to go over 85f. Under 40f – fermentation will almost cease.the most balanced fermentation (yeast and bacteria) will occur in a narrow band of about 74f – 78f. Over 80f, the starter will favor bacterial activity and lactic acid production. Under 70f, it will again favor the bacteria and acetic acid production. Enzyme activity, yeast and bacterial fermentation directly correlate to temp. Warmer = faster / Cooler = slower.
The fridge really just puts everything in Slow motion.

4. Type of flour
Flours will hydrate and ferment differently
Flours in order of starter activity (greatest to least)
While grain Rye
Whole grain Wheat
Unbleached flour
Bleached flour

Just to note – treated municipal water supplies may negatively impact the starter.
Personally, I would avoid bleached flours

5. Frequency of feedings
At room temperature, a starter can be fed from 1-3x a day. The higher the hydration, temperature and flour activity, the more quickly the starter will exhaust it’s food. A 100% or lower hydration fed with 33% starter or less and kept at 70f should easily go 24 hours between feedings.

In the fridge – it should only need to be fed once per week. To maximize time between feedings – change the hydration to 50%, feed with only 10% starter and unbleached flour. Refrigerate after feeding and it will last 2-3 weeks between feedings in the fridge.

A starter can change hydrations at any feeding. It can also change size at each feeding (up or down).

The best size starter you can keep is one that most closely matches how you use it.
Each feeding will require some % of starter to be removed. This is referred to as the discard. Ideally you use it to bake or
make other SD items.

The best time to use a starter:
For less sour breads – as it is peaking or early in the peak
For more sour breads – end of the peak or as starter is collapsing

A really generic feeding is 1:1:1 or equal weights of starter : flour : water.

The most common mistake made is to believe that feeding equal measures of flour and water is a 100% hydration starter.
Since hydration is weight based, you need to consider the different weights of flour and water.
1C of water weighs 236g
1C of flour weighs ~132g
Feeding equal measures results in a hydration of 178.7% (236/132) – not 100%.
It will bubble – not double in size.

Happy feeding.

A SD Starter is REALLY just another bread dough!

One of my wishes would be that every sourdough baker recognize that their starter is really just another form of bread dough.
The only differences are:

We don’t add salt (speeds fermentation)
We often keep it at a higher hydration
We don’t make a strong effort to develop the gluten
We don’t bake it – but feed it to perpetuate it.

The starter is comprised of flour water and yeasts (and bacteria).
When making dough, we add a portion of our starter to the flour and water.
When feeding our starter, we add a portion of our starter to the flour and water.

We have no concern to vary the amount of starter we add to a dough or to try different hydrations or different flours We should recognize that we can do the same things with our starter. Change the hydration – change the ratio of starter to flour to water, change the flour.

As we watch our starter – we can gain great insights into how our dough should perform – does it rise quickly or slowly – does it double
or triple or only increase by 75%? How long does it hold a peak? These help us know the health of our starter – but are also highly correlated to the flour we are using.

Watch how changes in temperature affect your starter… it will be the same with your bread doughs.

Want to better understand what overproofing is – watch your starter – it overproofs and collapses regularly…. the same thing that happens when it’s part of a bread dough.

It’s the ultimate ongoing science experiment- happening right in our kitchens

Learning All About Sourdough Starters

Maybe it’s time to talk about starters. Specifically – traditional flour and water based starters.

Taking the leap and beginning a starter seems a but intimidating – what method to follow – what to expect – to cover or not to cover – how to feed and list goes on. While it may seem complicated – it really is pretty simple.

For anyone who has made bread – you already know more than you realize.

The first thing you should know is that a starter is really just another form of bread dough. It is only missing salt. It actually behaves just like a bread dough.

Some useful things to know.

Despite a lot of folklore, starters do not really trap wild yeasts from the air (ok, maybe some) – but the majority of needed yeasts and bacteria are already contained in the flour. They collected on the wheat while it was growing and are still there after it has been milled into flour. They are just waiting for the right conditions to come to life. I know this is less mysterious than the concept of yeasts arriving via the morning breeze – but it actually means you can easily create a starter with just flour and water… no magic needed.

The second thing to know is it will be happy if you stir in some air, but it really does pretty much everything in the absence of air. Feel free to cover it.

A starter will consist of a variety of yeasts and lactic acid bacteria (LAB) – and while every starter will have a slightly different combination – there are a group of pretty common ones that are found in all starters – all over the world.

Starters, once established are acidic in nature. This is the first hurdle of a new starter. The desired yeasts and LAB will not colonize until the starter is suitably acidic.

The yeasts and LAB will live happily together each feeding on different sugars. But where do the sugars come from? Once again, the flour happily provides. All flours are predominantly starch (carbs). There are very few actual sugars (flour is not sweet). The flour has this part covered too. It contains natural enzymes that will convert the starches into sugars. They actually only convert starches that were damaged during the milling process – but that’s another topic. The flour needs only one thing to put all of this into motion – water!

So first things first. how to begin a starter. There are more methods of how to do this than one can possibly imagine. In my view, simpler is better. What you do not need, and in my view, do not want.

No added sugars

No added commercial yeast

No added fruits – except maybe one.

No added flowers

No added anything

Just two (maybe 3 ingredients)…

The 2 you can’t avoid are flour and water

Let’s talk about these a bit. Different flours work better than others when it comes to starters. A simple list – in order based on how well they work:

Whole grain Rye flour

Whole wheat flours

Unbleached white flour

Bleached white flour (I would suggest avoiding this one)

Water also makes a difference – some

municipal water supplies add things to kill microorganisms – the very things we are seeking to cultivate. You can try it – but I would suggest filtered or bottled water – at least while getting the starter established.

So the goal – mix the water and flour together and wait and wait and wait. Ok we have a little more to do.

I would suggest beginning a starter at 100% hydration. This means equal weights of flour and water. One of the most common misunderstandings is thinking that equal measures of flour and water will create a 100% hydration starter.

A quick side note – hydration is nothing more than the weight ratio of the water to the flour. If we have 100g of water and 100g of flour, we simply divide them. 100/100 = 1.0 Multiply by 100 to get a %. In this example, we see that we have a 100% hydration. If we had 125g of water and 100g of flour – it would be 125/100 = 1.25 or 125% hydration.

So why does measuring not create the same result (1c of flour and 1c of water, for example)? Well, it turns out that 1c of water weighs 236g while 1c of flour weighs ~132g. Our 1c + 1c is actually 236/132 = 1.79 or 179% hydration. This is quite a different result.

A starter can be pretty much any hydration- even when beginning one. Keeping the hydration lower makes many things much easier to observe – which will be important. 100% works well for a lot of reasons. I suggest you stick with it.

So the optional 3rd ingredient is pineapple juice. But – why would we want to add it?

Let’s talk about why we might consider this as a possible third wheel.

When we first mix flour and water together, our “starter” will actually be relatively non acidic.

Acidity is measured in pH. Flour typically has a pH of around 5.5 – 6.5 while water typically ranges from 6.5 to 7.5. A pH of 7.0 is considered neutral and the lower the number – the more acidic the item is. Our starter will start out with a pH around 5.5 – 6. When we are done, our starter pH will be around 3.8 – 4.3.

Changing the pH is actually the first phase of a new starter – it must go through a natural acidification process. When conditions are right, this will take around 2 days. Ideally, there should be little to no activity during this period. If your starter bubbles and rises on the first day – you should not be giddy – although it is tempting to want to believe it is that easy. If this happens, some yeasts other than the yeasts we want took hold. They will actually need to die off – add 1 day to the process.

Back to the pineapple juice – it is useful as a starter addition for the first day or two solely because it is acidic in nature with a  pH of 3.2 -4.0. Adding it instead of water simply causes the initial pH of the “starter” to begin already somewhat acidic. Somewhat of a kickstart – subtract 1 day.

For the first 2 days, you don’t really need to do much – an occasional stir is fine and may even be helpful. Mostly – relax and let it transform. What you hope to see during days 1 and 2 – nothing. Absolutely nothing.

The yeasts and LAB that will live in our starter and do all of the bread magic will not colonize until the starter becomes acidic.

Perhaps this is a good time to talk about what happens when we feed a starter – at least from a pH perspective and maybe a

little from a yeast and LAB perspective. Remember, our flour and water have much higher pH levels. Every time we add them to our starter it raises the pH or deacidifies  our starter. For a new starter, this is contrary to what we want. It also introduces a whole new set of yeasts and LAB (also in the new flour) some will be friendly and some not. Adding commercial yeast also just introduces a non desirable

strain that the starter will have to eliminate.

Important to note: The regimen for caring for a new starter is much more specific than all of the options for an established starter. While many will offer sage advice of how they care for their starters, much of it is actually detrimental to a new starter.

Day 3 – we should begin to see activity from the yeasts that are now colonizing in our newly acidic starter. Bubbles or some increase in the volume of the starter would

be common. By now the starter has been consuming the available sugars gladly made by the natural enzymes. It’s time to add food. We want to add food (flour) and more water to maintain the hydration- but we don’t want to raise the pH too much. A good balance is to feed with a ratio of 2:1:1. This means that for every 10g of starter we add 5g of flour and 5g of water. The old starter is one half of the newly fed starter by weight. This ratio should be maintained until the starter is established.

This brings us to that horrible topic – the DISCARD !!! Why oh why must you discard? It’s a basic principle of exponential growth. Since we have established that the starter will double in weight each time we feed it (it’s just how the 2:1:1 ratio works) we can quickly see that if we don’t do anything – it will be 2x as large, then 4x,8x,16x,32x,64x – well – you get the idea. Unless you are a bakery, this is not a good thing. It is FAR FAR less wasteful to just maintain the starter at a constant size. It can be whatever size you like, as long you keep the same ratios.

The second most common mistake is not discarding and not changing how much flour and water are being added. The starter is growing – but the food supply is not! It is not a happy ending!

Let’s say we want to keep a 120g starter.

Each feeding is simply 60g of starter and 30g each of flour and water. The 60g of leftover starter is the discard.

So – Let’s talk about the discard for a minute. It’s not like all the yeasts and LAB recognize that it’s feeding time and all run to the portion of the starter you are keeping. Nope – they are evenly distributed throughout. This means two things – each time you feed 2:1:1 and discard,  you reduce the existing populations of yeast and LAB by half. You raise the pH and toss in some other competing yeasts and LAB. (Be kind and stick with the same flour during the entire

process of establishing the starter). The other thing to note – the discard half is exactly the same as the half you keep – only you haven’t fed it. It still has the same

yeasts and LAB – they are just hungry. They will begin to die off – but there are a lot of them. It will take a while.

More on this later.

So days 4-7 – we just keep discarding and feeding – once per day should be fine.

It should get more and more healthy. It will begin to follow an identifiable pattern.

Let’s talk a little about temperature – all of the key things here – the enzymes, the yeast and the LAB are all incredibly temperature sensitive. When it’s warm they are really active. As it gets cooler, they all slow down. The cooler it gets, the slower they go. Since our goal is to develop active cultures, temperature is critical. Do not even think about the fridge at this point. So what’s best? 70-80f. They will be so happy. Below 70f – add 1-4 days.

Below 60f – add 10 days. Ok – I actually don’t know how many days – but you can extend a 5 day process to 14 or more simply by having a lower temperature. You should also avoid temps over 85f for all things starter and bread related. Off flavors tend to occur. A day or 2 at 85f may help colonize the LAB.

So – it’s day 5-7 – what should we observe. The starter will go through a cycle. The first part is just like every other bread dough.

OK,  almost – it is a little wetter (100% hydration) and doesn’t have any salt and we don’t go out of our way to develop the gluten.

Let’s start from when we feed it. After we feed it, we have raised the pH and reduced the yeast and LAB populations (discarding). The starter will go through a lull period – the same as a bread dough. As things normalize, the yeast will begin to produce carbon dioxide, which trapped by the gluten will cause the starter to rise – exactly the same as any other bread dough. The starter will eventually reach a peak – this is a combination of how much gluten is in the flour, how well you mixed it and it’s access to the remaining food.

Lower gluten flours may increase by 70-80% while high gluten flours may triple.

The fact that the starter increased in volume and how quickly is an indication of the health of the yeast. How much it rises is really more an indication of your flour strength.

It is likely worthy to mention – for those who did the equal measure feedings (1c +1c) – your starter is quite liquid in nature. As such, it will not have enough gluten strength to increase in volume, you will simply see all of the CO2 gas bubbles

float to the surface and pop. You would assess the health of the yeast by the number and rate of bubbles.

So back to our 100% hydration starter. It will reach a peak in volume and stall.

In a regular bread dough, this peak is our cue to divide and shape into loaves. Not so with our starter. We get to observe what happens to a bread dough when you simply let it continue to ferment. It will hold the peak for some time – how long is again a function of the gluten strength of

your flour. Eventually, the gluten will weaken (courtesy of some other enzymes naturally present in the flour) the available

food supply will diminish and the starter will collapse. All of these indications help us understand the overall health of the yeast and the general characteristics of our flour. Watching this process also shows what happens when a bread dough overproofs.

A brief sideline – starters and bread doughs are all about fermentation.

Yeast fermentation produces several things but the main two are carbon dioxide and ethanol. The CO2, when trapped by the gluten is what causes the starter (and bread doughs) to rise.

Bacterial (LAB) fermentation also produces several things but the main two are lactic and/or acetic acids. Acids are sour. It’s because of the LAB that it’s called sourdough. They bring a lot of benefits with them besides making acids.

Just to note – lactic acids are yogurty sour and acetic acid is vinegar – thus vinegary sour.

Back to our starter – Everything we have observed so far is all about the yeast. So what about the LAB? Well – the LAB have also been busy – producing lactic and/or acetic acids – helping our starter reacidify.  We could measure the pH or taste the starter – the only real ways to determine how healthy the LAB are. A little more about this later.

Back to days 4-7. We should begin to see the starter repeat this cycle after each feeding. If it is warm and healthy – we should begin to see the starter peak around 4-6 hours after feeding. Cooler temps will take longer.

Feed it once a day… It’s OK really. More often keeps reducing the population sizes and deacidifying the starter – neither desirable when trying to get the starter established.

Another thing to note about our yeast and LAB friends. The yeasts will tend to get established more quickly than the LAB. They also recover faster from the rise in pH that occurs when we feed it. A starter is usable for baking when it consistently repeats the rise and fall cycle a few times. This could be as short as 5 days – but typically may be more like 7-10 days. Breads baked with new starters are not likely to be very sour.

Once a starter has shown it is stable for several days – the rules can begin to change. The yeasts and LAB are fairly well established – the pH is being managed and the starter is able to tolerate some variation. I would be as consistent as possible – keep it warm, use the same flour, have regular daily feedings with a 2:1:1 ratio for at least 10-14 days.

If you miss a feeding – just feed as soon as you realize it – it will not be perilous. The yeasts and LAB have two primary goals – survive and reproduce – and they do both quite well. They hung out on the wheat relatively inactive for quite a well waiting for you to provide a happy home.

There are several things that we can change with regard to the ongoing care of our starter. Let’s talk about a few.

Hydration – so far we have kept our starter at 100% – but there is variety in life. A starter can be any hydration – but practically the range is about 45% to 200%. It is hard to physically get below 45% and over 200% it will run out of food very quickly. So what effect does changing the hydration have? Increasing the hydration will speed up fermentation and reduce the available food supply.

Let’s look why the food supply is reduced. Warning: math ahead!

Let’s start with our healthy 120g 100% hydration starter and change it to 200%. We know that at 200% – the water weight will be twice that of the flour.

For our 120g starter, that means it will need to be – 80g of water and 40g of flour. If we start with 60g of our existing starter – it will provide the first 30g of flour and 30g of water. We would add 10g of flour (40g – 30g) and 50g of water (80g – 30g). Since flour is the food supply – we should note that we only fed 10g of new flour.

It will get a little better with the next feeding as now our 60g of starter is already at 200% hydration. It is now 20g of flour and 40g of water. We now feed it with an additional 20g of flour and 40g of water. We doubled the amount of flour – but it is still only 20g.

Remember, the flour component from the existing starter has little food value as it has been previously consumed.

If we compare this to our previous feedings at 100% hydration, we were feeding 60g of starter and 30g each flour and water. At 100% hydration, the starter receives 1.5 times the amount of food it receives when it is maintained at 200% hydration.

So – let’s change it to 50% hydration. At 50% hydration the water weight will be half of the flour weight or the opposite of our 200% starter.

For our 120g starter, that means it will need to be – 40g of water and 80g of flour. If we go back and start with 60g of our existing 200% hydration starter – it will provide the first 30g of flour and 30g of water. We would add 10g of water (40g – 30g) and 50g of flour (80g – 30g). Since flour is the food supply – we should note that we now fed 50g of new flour.

It will be a little less with the next feeding as now our 60g of starter is already at 50% hydration. It is now 40g of flour and 20g of water. We now feed it with an additional 40g of flour and 20g of water.

To summarize – keeping our ratio of 2:1:1

At 200% hydration we are adding 20g of new flour at each feeding.

At 100% hydration we are adding 30g of new flour at each feeding.

At 50% hydration we are adding 40g of new flour at each feeding.

What does this mean? Simply – the higher the hydration – the more quickly the starter will exhaust it’s food supply. It will want to be fed more frequently. A 200% starter will need to be fed twice as often as a 50% starter. We can use this to our advantage.

The next thing we will talk about is feeding ratios. I will reference the ratio as starter:flour:water. (I have seen it as both s:w:f and s:f:w).

If you remember, our initial starter was 2:1:1. In the same spirit of “variety is the spice of life” – we can completely change the ratios of how we feed our starter. In fact, we probably want to!

The truth is – we already talked about the flour and water ratios when we changed hydrations.

At 200% hydration, our feedings were 60g of starter, 40g of water and 20g of flour. The ratio is 3:1:2

At 100% hydration, our feedings were 60g of starter, 30g of water and 30g of flour. The ratio is 2:1:1

At 50% hydration, our feedings were 60g of starter, 20g of water and 40g of flour. The ratio is 3:2:1

The only other thing we can change is how much starter we retain when feeding. It turns out that we can vary the amount from 5-50% of the new starter weight. It becomes a bit impractical to go beyond these limits.

What happens as we vary this %? As the % of existing starter gets smaller and smaller – two major things occur. We already talked about both of them

First, we are introducing a smaller and smaller population of yeasts and LAB into the newly fed starter.

Second, since a larger % of the newly fed starter is fresh flour and water, we dramatically increase the pH and the populations of competing yeasts and bacteria. This is why 5% is somewhat the practical lower limit.

What happens as we lower the % of existing starter. If you remember, the yeasts tend to recover faster than the LAB. So – we significantly de-acidify the starter, we reduce the yeast and LAB populations and we expect the yeast to recover first. This is also known as sweetening the starter or in the Goldrush days – sweeting the pot. This is most commonly how the baker feeds the starter if they want less sour breads. We reduce the starter pH, suppress the LAB (slower recovery) and add the starter to the dough early in its cycle – typically just as it is peaking. All favor less acid. Keep in mind, that as just as adding less yeast/starter to a bread dough will slow the rate of fermentation. The same will happen with your starter – it will take longer to reach it’s peak.

We should note that another common practice is to keep something like the 2:1:1 feeding ratio but feed 3 times every 8 hours. The net effect is similar as each feeding reduces the yeast/LAB populations and raised the starter pH.

At 10% starter and 100% hydration, we are feeding our 120g starter 12g of starter and 54g of flour and 54g of water. The ratio is 1:4.5:4.5 or 2:9:9

For more sour breads, the opposite is true. You want to keep the amount of starter added high – at 50%. You want to feed less frequently and you want to use later in the cycle – when the LAB are fully active… At the back end of the peak or even after the starter has collapsed.

The last wildcard is temperature. It is in my view, the unspoken ingredient added in all bread doughs.

78f (25c) should be embedded in the mind of every bread baker. It is the point at which yeast and LAB are somewhat in balance. As you go above or below it, the LAB will gain an advantage.

Just to note – above 80f (27c) and at higher hydrations the LAB will favor lactic acid and below 60f (16c) or at lower hydrations, the LAB will favor acetic acid (tangy sour).

An all purpose somewhat neutral safe happy flexing ratio for an established starter is 1:1:1 – equal weights of everyone.

How often to feed?

The answer really depends on the hydration, the temperature and your goal of sour or non-sour.

As we discovered – a high hydration starter kept at a warm temp will likely want to be fed every 12 hours.

A 100% hydration starter kept around 70f (21c) should be fed once per day.

A 50% hydration even less often.

Remember – as the hydration decreases, the amount of available food increases.

So – what about the fridge?

Good or bad?

I’d say it leans towards the bad side – but it excels at convenience for the baker who wants sourdough breads, bakes once a week or less and doesn’t want to feed daily.

For the ultimate lazy person (me), you can do a couple tricks – change the hydration to 50% before storing (lots of food) and since you know your starter is good – put it in the fridge right after you feed it (lots of food). The longer it stays out – the more active it will be and the more food it wil consume. The goal is for your starter to happily hang out for a week or two while you blissfully neglect it.

A high hydration starter that is fed and allowed to become fully active before refrigerating has already consumed a good portion of its food.

So – what does the fridge do?

The chillingly cool temps will simply slow everything down… the enzymes, the yeasts, the LABs. It is the baker’s slow

motion button. It will take a while for the starter to cool.

Around 35f (2c) – it will almost stop. Fridge temps vary and a 40f (4c) fridge will allow more fermentation activity than a 35f (2c) fridge. Just watch it.

To return a refrigerated starter to use – there are a few options.

Just use it. The yeasts and LABs are still Ll there hanging out. The longer it has been in the fridge – the less viable this option becomes.

Take it out and feed it. If it’s healthy, after a single feeding you should see it repeat it’s familiar pattern of rising. Feed it a couple times if you like. It never minds a warm room and food.

If you just want to extend it’s life in the fridge, take it out, feed it and put it right back. I know this creates anxiety for a lot of people. The starter really doesn’t care. It does not need to warm up or anything. It’s happy just to get fresh food. If you feel better or just don’t trust it , warm it, feed it, watch it rise and peak – then feed it again and put it back.

What if you neglect it a little too long?

Remember – yeast fermentation produces ethanol (alcohol). Left long enough unfed,

the gluten will completely deteriorate, the starter pH will reach a point that halts activity and the starter will separate with the alcohol on the top (occasionally the bottom). It is referred to as hooch. It is typically brown or black. If it is a low hydration – it may turn grayish on top.

What to do?

One of the more controversial topics – you can pour it off or stir it back in. From a pure starter health perspective, it is simply better to pour it off. It is a byproduct and not the starters best friend. For those who want sour or like the flavor, stir it back in.

As a starter remains unfed, the yeast and LAB populations will slowly die off – they will mostly go dormant.

Personally, the regular appearance of hooch means you are not adequately feeding the starter. I do not encourage this.

The last topic for now – discarding! Perhaps a poor choice of terms – the discard can actually be the portion used for baking. To maintain the feeding ratios, you either need to remove some of the existing starter to keep the starter a constant size or recognize that the starter is going to keep getting larger and larger.

You need to keep adjusting the amount of food up as the starter grows.

In a perfect world, you would keep your starter at a size that matches your baking.

You would feed it and use the portion removed for baking. No discard in the sense of throwing part away.