A short essay about my starter, Enrico
Enrico and I have a love hate relationship.
I don’t particularly like him when I have to wake up at 6 am to feed him, or when its 11 pm and 👨🏼 and I are watching Friends on the couch and I suddenly remember I have to feed him - again. I like him even less when he makes a mess in the house when I’m taking his discard to flush it down the toilet and it oozes all over my floor. 👨🏼 doesn’t really love him when he goes to the bathroom and sees part of him stuck to the walls of the toilet like cement, and therefore, I don’t like him then either. I get furious at him when I’m about to make cookies and realise I do not have enough whole wheat flour for my recipe because, obviously, he likes to hog that flour, being fed twice a day with it. 😒
But, when he starts rising a couple of hours after being fed, I love him. When he starts forming bubbles that I can see through his jar, I love him– even if it's actually him "farting". When I see he has tripled in volume, per the rubber band surrounding his belly, I LOVE him. When I bulk ferment my dough and beautiful fermentation bubbles peak through, I love him. When I take the lid off of my Dutch oven and see a gorgeous spring on my loaf, I love him. When I cut into the loaf and I see an attractive open crumb, oh my, I adore him. When 👨🏼 sees me jumping around the house with a smile across my face excited about a successful loaf, he loves Enrico too. Or when 👨🏼 and I grab a slice of bread, spread room temperature butter, sprinkle some flaky salt, and give it a bite, mamma mia, we worship him.
What is a sourdough starter?
A sourdough starter is essentially an active colony of wild yeast. So first, let's understand yeast and how it works.
Yeasts are microorganisms that, when fed, emit gasses (CO2). These gasses get trapped inside the dough and, therefore, make it rise. Imagine inflating a balloon with your mouth. The balloon inflates as you blow air inside it. The same thing is true for yeast in dough, except there are thousands, if not millions of yeast emitting gasses and creating small air pockets inside our dough.
Commercial yeast (meaning the ones you buy at the super market) act in the same way that sourdough starter does. However, commercial yeast undergoes a process where a specific type of yeast is isolated from the rest, and certain desired characteristics are maintained, essentially domesticating the yeast. This process makes commercial yeast hundreds of times stronger than wild yeast, which is why using store-bought yeast can yield a proper loaf of bread in a matter of few hours. However, this is not necessarily a good thing.
Wild yeast cultivated through a sourdough starter makes the bread making process longer because it is not domesticated, and, therefore, takes more time to leaven your bread. This means that, during this long process, the wheat in our dough is fermenting and becomes more digestible for our digestive system, eliminating a great part of the discomfort produced by eating gluten. This effect is not mimicked when using commercial yeast because everything happens so quickly there is no time for fermentation, or in other words, the predigestion of wheat.
All in all, a sourdough starter is a colony of different types of wild yeast, that release gasses (I like to call them farts) inside your dough and make it leaven.
So, how do we cultivate these mystical farting creatures?
There is a very common misconception that yeast is in the air, and that sourdough starter feeds from that. The truth is, those microorganisms are actually present in our flour, and that’s where it all starts– not in the air.
A sourdough starter is created by mixing together flour and water. That’s it. That’s how you grow a colony of wild yeast. The humidity prompted by the presence of water in flour activates, per se, the yeast and other microbes naturally found in flour. Then, the recently activated yeasts will start to feed on the starch found the flour, they will then fart (or emit CO2 gasses, however you want to refer to the process), and your starter will rise.
There are three main variables that can make your starter more active: flour, water, and temperature.
Flour
Whole Wheat Flour
Whole wheat flour is less processed than regular all-purpose flour, this means that there are more microbes still present. If you use whole wheat flour, your starter will ferment quicker and rise quicker, and the bubbles present will be bigger. Further, whole wheat flour absorbs more flour than all-purpose which means your starter will look less liquid if you use this type of flour.
Rye Flour
Rye flour is also known for boosting fermentation and activity in sourdough starters. Like whole wheat flour, it is able to absorb more water than all-purpose flour.
Bread Flour
Bread flour has a higher protein content than all-purpose flour. If you remember from my brioche dough recipe, this means that the dough is able to create a stronger gluten network. The dough will be more elastic, which allows it to hold more air inside, and, it expands without breaking or tearing. If you use bread flour, you will probably see bigger and more abundant bubbles in your starter, than all-purpose flour, and it also absorbs more water.
Stone-Ground Flour
Much of the flour we buy at grocery stores are grinded with steel rollers; they aren't stone ground. If you can find an organic stone ground flour (which will most likely be whole wheat or rye) your starter will benefit from it because the stones add more minerals and microbes that will strengthen the activity of your starter.
All-purpose Flour
All this being said, it is perfectly fine to use all-purpose flour for your starter. There should be no significant change to your loaf. The only difference will be in flavor.
Many people feed their starters a combination of flours. For example, 50% bread flour and 50% whole wheat flour is a combination I have sometimes used. It adds different characteristics to your final dough, whether it be in flavor, texture, dough strength, or more, and I urge you to try it out. See what works for you and discover what you like.
You can build a starter pretty much with anything – from many more types of flour than I mentioned above to literally anything. I’ve seen people use sweet potato starters and make stunning loafs. If you wish to be out of the box and try crazy things, you’ll have to experiment, take notes, and recreate what works best.
Water
Even the most seemingly mundane of all ingredients can have a significant impact on your starter. I would say water has a greater influence on the health of your starter, even more than the flour you use –unless you use bleached flour, which will give your starter little chance of being healthy and active.
Type of Water
I did not know what to call this section, so I just opted for "type of water". What I mean by this is where you are taking your water from and how that affects your starter. If you live in a city where water is highly calcareous (my case), or has many chemicals to make it drinkable, your starter will suffer. These foreign chemicals inhibit the growth and reproduction of the wild yeasts you are trying to cultivate.
I used to use water straight from the faucet to feed my starter and my loafs were a bit flat and sad. I then bought a water filtering jug and started filtering the water I used on my starter. Although I cannot say with 100% confidence that this change was what made my starter actually leaven my bread, I did see tangible improvements. My loaves started having amazing oven springs, the crumb started to open more, and the taste was more characteristic of sourdough bread, all while keeping the same bread-making base technique.
Some say this is a myth, while others swear by filtering their water. So, as a rule of thumb, I do filter my water– I mean, it doesn’t hurt. If you do not have a filter already built into your faucet and do not want to buy a filtering jug, then you can just fill a regular jug with water and let it sit for about 20 minutes, at which point, calcareous and other sediments that could potentially inhibit the activity in your starter, would have sunk to the bottom of your jug.
Water Temperature
Like humans, yeasts feel more comfortable in a warm and cozy environment. Therefore, you do not want to add cold water to your starter. This will just impede its activity and you will find yourself with a blob of wet flour. Instead, use room temperature water. You can also even warm it up a bit on the stove (no more than 27°C) and add it to your starter for an extra oomph or if its extremely cold in your kitchen.
This is also a way for you to control the rise and schedule of your starter, as warm water will speed up activity. If you are short on time and need your starter to mature faster than usual to use on a loaf, this is a viable option. Although, don't expect your starter to go from taking six hours to being ready in just one or two. It does cut some time, but the effect is not dramatic.
All this talk about flavor, but what does it even mean?
To understand how your starter can affect the flavor of your bread, we must go deeper into the science behind it all.
Sourdough starter has two (known) microorganisms that cause it to ferment: yeasts and lactic acid bacteria (LAB). The latter are present in other fermented foods and are the predominant reason for the flavor and texture of your final sourdough loaf. Furthermore, there are many types of LAB that ultimately produce the variance in flavor that I talk about when explaining the different types of flour you can use for your starter (Kimbell, 2017).
Here are the flavor profiles that will emerge depending on the different types of flour you may use, which depend on the kind of LAB present in them (as mentioned above).
Whole wheat flour: sweet and sour flavor.
White flours (bread, all purpose): these have a characteristically sweet, yogurt-like flavor.
Rye flour: more prominent sour flavor
(Kimbell, 2017)
Depending on the character and profile you want your bread to have, you can choose what type of flour to feed your starter.
Temperature
Temperature is the last variable you can use to manipulate your starter. Like I mentioned before, yeasts and other micro-bacteria present in your starter prefer warm places, and it is in warm temperatures that they will flourish and show their true, beautiful, farty colors. However, this does not mean that you should heat up your starter. Please don't do that. You will have to find a nice warm spot in your kitchen for your new family member to inhabit.
If the air around your starter is too cold, it won't show much activity, and it will probably take a very long time to establish a healthy and active colony of wild yeast. For example, I found a cupboard on top of my fridge that benefits from a warm environment thanks to the heat that the fridge exudes. In there, my starter flourishes beautifully and remains warm and cozy.
I recently traveled with my starter and I noticed the kitchen where we were staying was quite cold. I left my starter there overnight to see what changes it would have on its development. The next morning, I could clearly tell its activity had significantly slowed down as it was still maturing at 3-4 hours past its usual peak point. After this, I took my starter to sleep with me in my room (which was evidently warmer) and it thanked me going back to its usual cycle (ish).
Other ways you can control your starter's temperature is by controlling the temperature of the water you use to feed it, as I previously mentioned.
Tools
As you have probably understood by now, sourdough business is very much a precise science (like anything else baking). You will need specific tools to successfully give birth and raise an active and thriving colony of wild yeast.
Glass Jar
This is ultimately your starter's home. Due to the acidity that is in the nature of any sourdough starter, I suggest a glass jar, although plastic can be used too. I use these Weck jars that are straight-sided and offer a large space for my starter to grow. You can use whatever jar you have at hand, but the straight sides will make your life much easier when feeding your starter and maintaining the container in proper condition. Curved sides will limit your ability to scrape down the sides and you will end up with starter buildup.
Rubber Spatula or Wooden Spoon
You will need a trusty tool to stir you starter whenever you feed it. This tool must be sturdy enough to thoroughly mix your flour, water, and starter during each feed. I opted for a rubber spatula, specifically this one from IKEA because I like that it is completely smooth. This makes the feeding process much more straightforward and does not give me any trouble when scraping into my jar any excess starter.
You can also use a wooden spoon, but I find it to be a little bit uncomfortable and unhelpful in maintaining a clean jar, as it does not do a good job in scraping down the sides.
I have noticed people abstain from using any metallic utensils when refreshing their starters. After looking into this matter, I found that some people state that metal might mess with your fermentation, others are more concerned about the well-being of their utensil as the starter is acidic and can deteriorate metal. All in all, I don't really think using a metal spoon harms your starter, as in many occasions I have been guilty of using one. However, I am extremely superstitious and prefer to be safe and not use any metallic utensils when handling my starter.
Kitchen Scale
If you so much as pretend to build a healthy starter using measuring cups, I have nothing to say to you other than read this, and shame on you. This is probably the most crucial tool of all and the only one that cannot be replaced. Your measurements have to be EXACT, and the only thing that will assure this will be the use of a kitchen scale.
Thermometer (optional)
I did not have a thermometer when I created my sourdough starter, so it goes without saying that this tool is not completely essential. However, a thermometer is an incredibly helpful tool to have in your kitchen, and once you have it, it will become your right hand and an extension of yourself. In this case, the thermometer will help you asses the temperature of your water. Like I said, you can always just go with room temperature water, but if you want to speed up the process and add warmer water, you might want to have a thermometer in hand to make sure you won't incinerate your poor yeast colony. Moreover, when your starter is up and running and you want to make bread, a thermometer will be indispensable for proper, controlled bread making.
How to Build a Sourdough Starter from Scratch
Before you even start
Gather your tools together and make sure you have everything you need.
Weigh the jar you will be using, without anything inside it and without its lid. This will help you determine the amount of starter to leave inside the jar when refreshing/feeding your starter. Make sure you weigh the actual jar you will be using, and not one that looks similar or even the same exact jar from the same brand but not the actual one you will be using. Like I mentioned before I use Weck jars for my starters. The first one I ever used weighed 400 g without the lid. I broke that one and had to buy another one to replace it, and the same exact jar weighed 390 g. Moral of the story: weigh the actual jar you will be using.
Another very important thing is that you need to know that building a sourdough starter takes time. Not only does your starter need to show signs of life (which for some people will happen in the first day), but it also needs to get to the point where the colony of yeasts is very much established. The latter takes around 7 days and for some people it can take up to 14 days. So, do not be tempted to use your starter before the first seven days are up, and if your starter doesn't look very lively, it might take you more time.
DAY ONE
To your empty, clean jar, add
50 g of all-purpose flour
50 g of whole wheat flour
115 g of room temperature water
With your spatula or wooden spoon, mix thoroughly, until no dry spots of flour remain. rest the lid on the jar and place in a warm spot in your kitchen for 24 hours.
IMPORTANT: if you chose a jar with a screw-on lid, DO NOT screw it on. Just place the lid loosely on top. You want air to be able to go in and out of the container, specially out, because your starter will, at some point, start emitting gases. If your jar is tightly sealed, there will be no place for the CO2 to go and you jar will end up exploding from the pressure inside.
DAY TWO
Discard all but 75 g of starter. To do this, the weight of the empty jar without the lid will come in handy. If your jar weighs 390 g like mine, all you have to do is (390 + 75 = 465g) scoop out the flour and water mixture until the weight of the jar is 465 g.
Then add,
50 g of all purpose flour
50 g of whole wheat flour
115 g of room temperature water
First, add water into the jar containing the leftover starter. With your spatula or wooden spoon, stir the mixture so as to dissolve the remaining starter in the water. Next, add the flour and stir thoroughly until no dry spots remain. Rest the lid on the jar and place in a warm spot in your kitchen for 24 hours.
You have just performed a feeding.
Note: By adding the water first and dissolving the starter instead of adding all the ingredients at the same time, you are ensuring that the starter will be mixed thoroughly and equally throughout the new flour added. This will minimize your mixing time and effort.
Agin, you should completely discard the flour and water mixture you previously took out from the jar. This mixture is nothing but flour and water. It most likely has no microbial life in it and therefore cannot be used to make bread or any other sourdough discard recipes. Even if it did have the slightest hint of activity and fermentation, the colony is not yet established. In short, discard everything without looking back. It will be fine.
Important terms
Feed / Feeding: When you discard part of your starter and add more flour and water (aka food). This is often also referred as refreshing your starter.
Discard: the starter left after a feeding, which typically gets thrown away.
DAY THREE
Discard all but 75 g of starter.
Then add,
50 g of all purpose flour
50 g of whole wheat flour
120 g of room temperature water
First, add water into the jar containing the remaining starter. With your spatula or wooden spoon, stir the mixture as to dissolve the remaining starter in the water. Next, add the flour and stir thoroughly until no dry spots remain. Rest the lid on the jar and place in a warm spot in your kitchen for 24 hours.
If your starter had been showing sings of life, they will most likely stall after this feed. Do not worry, your starter did not die. This behavior is normal and part of the cycle.
Important terms
Signs of life: signs of life in a sourdough starter are typically when your starter is bubbly, both inside and in the surface, and when, due to the bubbles and air trapped inside, your starter rises in the container where it lives. Typically, a good sign of life is when your starter rises after several hours, and falls back down before being fed again.
DAY FOUR
Discard all but 75 g of starter.
Then add,
50 g of all purpose flour
50 g of whole wheat flour
100 g of room temperature water
First, add water into the jar containing the remaining starter. With your spatula or wooden spoon, stir the mixture as to dissolve the remaining starter in the water. Next, add the flour and stir thoroughly until no dry spots remain. Rest the lid on the jar and place in a warm spot in your kitchen for 24 hours.
DAY FIVE
Discard all but 75 g of starter.
Then add,
50 g of all purpose flour
50 g of whole wheat flour
100 g of room temperature water
First, add water into the jar containing the remaining starter. With your spatula or wooden spoon, stir the mixture as to dissolve the remaining starter in the water. Next, add the flour and stir thoroughly until no dry spots remain. Rest the lid on the jar and place in a warm spot in your kitchen for 24 hours.
DAY SIX
Discard all but 50 g of starter.
Then add,
50 g of all purpose flour
50 g of whole wheat flour
100 g of room temperature water
First, add water into the jar containing the remaining starter. With your spatula or wooden spoon, stir the mixture as to dissolve the remaining starter in the water. Next, add the flour and stir thoroughly until no dry spots remain. Rest the lid on the jar and place in a warm spot in your kitchen for 24 hours.
At this point, the ratio has changed to 1:2:2 (1 part starter, 2 parts flour, 2 parts water). As the starter starts coming alive and the wild yeast colony starts to grow roots in your jar, it is important to start lowering the ratio of starter to the rest of ingredients. This is because at this point your starter is becoming stronger, more acidic, and fermenting more efficiently. If you keep adding 100 g of flour and water respectively to 75 g of starter (which was about a 1, 1.3, 1.3 ratio) the starter will eat up the starches too fast and as it becomes hungry it will become more acidic. I know its called a sourdough starter, but that does not mean you should let acidity run wild. Starters that are too acidic are not healthy starters and will not produce a pleasant loaf. BELIEVE ME.
DAY SEVEN (and onwards)
Discard all but 20 g of starter
Then add,
50 g of all purpose flour
50 g of whole wheat flour
100 g of room temperature water
With your spatula or wooden spoon, mix thoroughly, until no dry spots of flour remain. rest the lid on the jar and place in a warm spot in your kitchen for 12 hours.
Now, the ratio of starter to flour and water is 1:5:5 (1 part starter, 5 parts flour, 5 parts water). At this point, your starter will more likely be active, healthy, and finally established. This means that from this day forward you should be able to bake a loaf of sourdough bread, or use the discard to make other baked goods, like my sourdough pancakes.
Some Things to Keep in Mind
Feeding Ratio
This is the ratio I use to feed my starter every day (1:5:5). You can scale up or scale down this ratio depending on your needs. For example, when I know I will not be baking anything, I keep my feeding to a minimal amount to reduce waste and minimize the consumption of flour. So, when I'm not baking, to 10 g of starter I feed 50 g of water and 50 g of flour. However, if I know I will be baking the next day, I will increase the starter left in my jar to 20 g, making the amounts for flour and water 100 g each. All of these feeding amounts are still within the 1:5:5 ratio.
You can also manipulate this ratio depending on your schedule. For example, if you want your starter to peak faster, you can always go back to that 1:2:2 ratio. On the other hand, if you have more time to spare you can keep that 1:5:5 ratio and give your starter more time to consume the starches and buy yourself some extra time before it peaks and it's time to inoculate your dough.
Important terms:
Peak: This term refers to when your starter has consumed all the starches in the flour since the last feeding and stops growing. When your starter has just been fed and starts to grow, it will do so in a slight domed shape, and when its at its peak it will start to flatten out.
Inoculate: This term is used to describe the addition of starter to any bread recipe.
Resting Period
You might have noticed that from the 7th day onwards you will only be allowing your starter 12 hours before you feed it again. This means you will be refreshing it twice daily as opposed to only once. This is a very important change that will have a big impact on your starter's health. As I briefly mentioned above, when your starter has consumed all the starches in the flour since its last feed, it will become hungry. This will trigger the starter to becoming acidic. If you do not feed your starter at that point, it will fall into a vicious cycle of acidity that will eat your loaf's gluten structure making it unable to have a dramatic and beautiful oven spring.
But what changed? Why is it that now it's essential to feed it twice daily? Well, at this point your stater will most likely be active and healthy, like I mentioned before. This means that it will develop faster than its "dormant" half dead half alive self. Therefore, it will become hungry quicker.
To ensure consistent results, you will have to feed your starter every 12 hours, for example, at 8 am and 8 pm, or 10 am and 10 pm. I am a night owl, so I usually go for 12 pm and 12 am. Make sure to keep in mind and follow all recommendations on water type and temperature to further raise your starter into becoming strong and resilient.
Storing Your Starter in the Fridge
By now, having a sourdough starter might seem like a huge commitment – at the end of the day it is a living and breathing (and farting) organism that needs to be fed twice daily. Some say it is like having a pet, which is why you will see the majority of people decide to name their starters. I heard once somewhere that if you name it, you are less likely to kill it. Yes, your starter can die if you do not take proper care of it.
However, if you are someone that bakes occasionally, and not every week, you can store your starter in the fridge and reduce feedings along with time and effort spent caring for it. When you have successfully established your colony of wild yeast (aka, after the first seven days) you can transfer your starter into the fridge and feed it only once a week.
When you do this, follow the exact same feeding recipe of day seven and let the starter rest in your counter at room temperature for three or four hours before transferring back into the fridge for another week before its next feed.
What is that Grey Liquid on Top of My Starter?
Its called hooch, and it is telling you that your starter is hungry and you should feed it ASAP. This liquid is basically acidity that has been produced by your starter because it's hungry. If you keep your starter at room temperature and feed it twice a day, you will most likely not experience this. However, if you opt for storing your starter in the fridge, it is very likely that it will develop a layer of hooch. This does not mean your starter is dead, or that it has gone bad. Just pour off the hooch, feed your starter, and all will be right in the world.
How Should My Starter Smell?
The obvious answer here is that your starter is supposed to smell sour. However, in this case the obvious answer is the wrong answer. To some extent, yes, your starter will have hints of acidic/sour smells, but it should not be, by any means, overpowering and unpleasant. Healthy starters have hints of sweet fruity smells, and ferment-y fruit. If your starter smells so bad you can barely sniff it, somethings up. Check your ratios, check your feeding schedule, check your water temperature – you must be doing something wrong.
For example, my poor starter currently smells like vinegary feet. Disgusting, I know. That's because I was not very punctual during his feedings, and some nights I even forgot. In my defense, I was not home during that period so its was bit hard to be on track. To remedy it, I'm being extremely punctual and meticulous in his feedings and I'm even feeding it before it peaks, so I can keep the fermentation and acidity to a minimum while it gets back to normal. Also, I won't even attempt to bake a loaf because I know his current acidity is so high, the gluten network in my bread would be weakened and I will end up with a pebble of a loaf.
Using Whole Wheat Flour to Build Your Starter and then Changing to Other Types of Flour
My recipe to build sourdough starter from scratch involves the use of whole wheat flour. This is because, as explained above, whole wheat flour encourages activity in your starter due to the lack of processing and therefore higher presence of yeasts and other microbes. The use of whole wheat flour almost ensures you are able to build a healthy and active colony in seven days.
This being said, you can definitely use entirely all-purpose flour to create your starter. This, however, will most likely take more time. Moreover, if you want a white flour starter and not necessarily a whole wheat one, all you have to do is build the starter exactly how I outlined and from day eight onwards you can feed it only white flour. This applies to all types of flour.
I hope all this information has not deterred you from jumping on the sourdough starter wagon. I know it seems overwhelming and you might fear killing your starter– we all do. However, sourdough starters are very resilient, once the colony has been established, and if you forget to feed it once or twice, it will definitely come back to healthy life. However, if you do fall under the cycle of not feeding it regularly on schedule, your starter will suffer– it will become acidic and if you're new to this process you won't recognize it straight away. Longterm, and actually also short term too, this means that you will not be able to bake nice looking and/or tasting loaves.
Enrico and Bianca
Enrico and Bianca are my two sourdough starters.
Enrico
Enrico is a 100% whole wheat starter. He is fed at 1:5:5 ratio every 12 hours. He is the light in my eyes, the joy of my days, and the sour to my dough. We have gone through many things together, good and bad, which has made me an expert on all things Enrico. I know when he's feeling well, when he's not feeling that well, when he has peaked, when he has gone past his prime point... I know everything about him. That is because I carefully observe him and how he develops in specific conditions and what kinds of loaves he produces in those circumstances. The only way you will get to know your starter is by experimenting with it, observing it, baking with it, smelling it, tasting it (yup), and by being so obsessed with it, your boyfriend gets jealous about him.
Enrico is the motor of all my sourdough loaves creations. He has powered 100% white flour loaves, 50% whole wheat, he has also been introduced to spelt flour, buckwheat flour, rye flour, and is waiting to work with Kamut® flour and whole wheat spelt flour. He has also leavened doughs with a high amount of seeds and olives, and has always yielded an outstanding flavor.
Bianca
And How to Reproduce Your Existing Sourdough Starter
Bianca is a 100% bread flour starter. Like Enrico, she is fed at a 1:5:5 ratio every 12 hours. Bianca was created off of a piece of Enrico, following my desire to bake all of my breads with sourdough – including focaccia, brioche, donuts... you name it. I specially want to stray away from commercial yeast because, believe it or not, gluten causes me some discomfort. Therefore, Bianca will fulfill my cravings for brioche, and any other predominantly white bread. So far, I have worked with Bianca very little. This is mostly because I am obsessed with mastering my "regular" sourdough loaves using Enrico, but Bianca has yielded a couple of very fluffy and delicious brioches.
Going back to the part where I said Bianca was created off of a piece of Enrico, you can very much give birth to a new starer with the help of an already existing one. This way, you do not have to wait until the colony of yeast is established completely because you are using one that is already strong and active. When you feed your starer, instead of flushing away the discard, pour 10 g of it in another clean jar, feed it your desired flour, and you have a new starter! Likewise, you can share your starter with your friends and neighbors, or if you do not want to go through all the process of creating your starter, you can always phone a friend and ask for a bit of theirs. If you don't have any friends that have a sourdough starter, I'm sure your local bakery will sell you, or even gift you, a bit of theirs. So, there is really no excuse to not have a starter.
I know it is a lot of information to take in at once. You do not have to understand or take it all in right now. As you start your sourdough journey, you will start having questions, and while I am always available to answer them (always!), refer to this document first and your question will most likely be answered.
I strongly encourage you to watch your starter closely, take notes on what goes right and what goes wrong, refer to this information when needed, and soon enough you will be a sourdough starter master.
Sources
Kimbell, Vanessa, and Nassima Rothacker. The Sourdough School: the Groundbreaking Guide to Making Gut-Friendly Bread. Kyle Books, 2017.