People ask for the “best water” for sourdough because they see conflicting advice: tap water will kill your starter vs I use tap water every day and it’s fine. Both can be true, depending on what’s in your water and what stage of sourdough you mean.
The useful goal is not find the best water you use. It’s: learn when water actually limits fermentation or dough behavior, and when it’s just background noise.
While water matters, it’s not the main driver in sourdough. Most minerals, enzymes, and wild microbes actually come from flour, not water. That means water quality usually plays a secondary role—unless you’re dealing with heavily treated tap water, extreme mineral content, or very pure water like distilled or RO without remineralization.
What people usually think this means
Most people are trying to prevent two feared failures: (1) a starter that won’t rise, and (2) dough that won’t ferment on schedule. So “best water” becomes shorthand for “water that won’t mess up yeast and bacteria.”
The catch is that sourdough is not one organism and not one process. It’s a shifting community (wild yeast + lactic acid bacteria) interacting with flour chemistry, temperature, time, and your feeding pattern. Water is one input, but it’s rarely the only one.
Understanding Snapshot — what most people get right (and wrong)
What people think:
-
Chlorine in tap water kills sourdough microbes, so you must use filtered, spring, or bottled water.
-
More minerals automatically improve fermentation and crust.
-
Distilled or RO water is “cleanest,” so it must be safest.
What is actually true:
-
Most tap water works fine for both starter and dough because disinfectant levels are usually low enough that flour microbes still thrive.
-
Problems show up when disinfectant is high (or chloramine is used), or when mineral/buffering balance is extreme (very soft, very hard, or sodium-heavy softened water).
-
“Pure” water (distilled/RO) can work, but can also remove helpful minerals and buffering patterns you didn’t realize you were relying on.
When the intuition works:
-
If your water smells strongly of chlorine, or your city uses chloramine, changing water treatment can remove a real constraint.
When it breaks:
-
When a starter is slow due to temperature, feeding ratio, or immature early-day biology, and water gets blamed because it’s the easiest variable to swap.
Takeaway: Water matters most when it’s unusually treated or unusually mineral-balanced—not because tap water is automatically “bad.” Using RO or distilled water can sometimes slow fermentation or affect structure, but this effect is usually subtle. For most home bakers, the difference is small unless the water is extremely low in minerals or the recipe relies heavily on water chemistry for fermentation balance.
Is tap water always worse than filtered for yeast and bacteria?
Not necessarily. Municipal tap water typically contains low levels of disinfectants designed to keep water safe during distribution—not to sterilize it completely. In most cases, this level isn’t strong enough to kill yeast and bacteria inside a flour-based sourdough starter, where microbes are protected within a dense, nutrient-rich matrix.
The real question is: what is your tap water treated with, and at what level? Many municipal systems use chlorine or chloramine at concentrations designed to protect pipes, not to sterilize flour in your jar. Flour brings a large microbial load and nutrients. In most kitchens, that ecosystem still establishes itself even with normal tap water.
Where tap water can be worse is when:
-
It has a strong chlorine odor (often after a system flush or seasonal change).
-
It’s treated with chloramine, which is more persistent (more on that below).
-
Your fermentation is already on the edge (cold kitchen, underfeeding, very young starter), so a small inhibition becomes noticeable.
Real-life example: someone starts a new starter in winter at 18–19°C (65–67°F). Feeding is inconsistent. The starter barely bubbles by day 3. They switch from tap to filtered and see improvement—but the hidden change is also that they warmed the jar and fed more regularly because they were “trying harder.” Water wasn’t the only lever.
Takeaway: Tap water isn’t “worse” by default; it’s worse when disinfection or conditions make microbes’ job harder.
“More minerals = better crust” (and why that’s only sometimes true)
Minerals can help, but “more” is not a rule.
A helpful mental model is: minerals influence dough strength and fermentation speed indirectly. Calcium and magnesium contribute to “hardness.” In moderate ranges, they can support consistent fermentation and dough handling. But too much hardness can make dough feel tighter and less extensible. And some “minerals” people add (or get from softened water) are not the helpful ones.
Also, crust quality is not a single output. Crust depends on:
-
fermentation (gas and acids),
-
sugars available for browning,
-
baking temperature and steam,
-
and dough strength and shaping.
Mineral content might nudge one part of that system, but it doesn’t override the rest.
Real-life example: a baker switches from moderate tap water to very hard well water. Dough suddenly feels “strong” but tears during shaping and doesn’t expand well in the oven. They think they need even more minerals “for crust,” but the issue is now too much tightness, not too little nutrition.
Takeaway: Moderate minerals can help; extremes can quietly create new problems.
Where that understanding breaks down
This is where people get trapped in one-variable explanations. They see a sluggish starter or slow bulk fermentation and conclude: “It must be chlorine.” Sometimes it is. Often it isn’t.
The better approach is: understand what each water factor can and cannot do—especially disinfectants and “purity.”
Why does “chlorine in tap water” get blamed for everything?
Because chlorine is a clear story: chemical kills microbes. It feels satisfying and controllable.
But chlorine’s real impact depends on:
-
concentration (which varies by system and events),
-
contact time (how long microbes are exposed),
-
and whether you’re talking about a young starter or a mature one.
In a mature starter, microbes are numerous and resilient. They also live in a thick, flour-based matrix, not in plain water. A typical refresh dilutes inhibitors. So low-to-moderate chlorine often doesn’t stop fermentation.
Chlorine gets blamed when:
-
a starter is young (days 1–4), where the ecosystem is unstable and small differences matter;
-
the kitchen is cold, so growth is slow already;
-
feeding is too small or too infrequent, so the culture never “wins”;
-
or people use the float test as a hard gate and panic.
Real-life example: a starter doubles reliably all week. Then one day it stalls after feeding. The baker assumes chlorine changed. But the real change was a colder countertop overnight and a smaller feed. Chlorine might not have moved at all.
Takeaway: Chlorine is a possible constraint, not the default culprit.
Why doesn’t letting water sit remove chloramine (and when boiling helps)?
People often hear: “Let tap water sit overnight to evaporate chlorine.” That advice is incomplete because chlorine and chloramine behave differently.
-
Free chlorine (the “pool smell”) can dissipate over time, especially with air exposure and agitation. Letting water sit can reduce it.
-
Chloramine (chlorine + ammonia chemistry) is designed to be more stable in the distribution system. It does not “gas off” the same way, so letting water sit often does very little.
Free chlorine refers to dissolved chlorine gas or hypochlorous acid used for fast disinfection, while chloramine is a more stable compound formed by combining chlorine with ammonia. Chloramine lasts longer in pipelines, which is why it doesn’t dissipate easily like free chlorine, according to CDC guidance on drinking water disinfection.
Boiling can reduce disinfectants, but the effect depends on:
-
how long you boil,
-
whether the disinfectant is primarily chlorine or chloramine,
-
and your starting concentration.
Boiling also changes nothing about other water chemistry (like sodium from a softener), and it can concentrate minerals slightly by evaporation.
Real-life example: a city switches seasonally to chloramine. A baker keeps letting water sit overnight, expecting the same effect as before. Their new starter stays flat for days. Nothing about their flour changed—the treatment did.
Takeaway: “Let it sit” mainly targets chlorine; chloramine often needs different handling. Letting water sit works well for free chlorine, but not for chloramine. Boiling can reliably reduce free chlorine because it evaporates easily. However, chloramine is much more stable and does not break down effectively with boiling alone, especially at typical kitchen boiling times. In cities using chloramine, filtration (like activated carbon) is usually needed instead of waiting or boiling.
When “pure” water (distilled/RO) can backfire without you noticing
Even here, it’s important to keep perspective. Most of the nutrients and minerals that support sourdough fermentation come from flour, not water. So removing minerals from water usually only becomes noticeable in edge cases—like very weak starters, long fermentation cycles, or when using extremely low-mineral water without any dietary mineral input from flour. “Pure” water removes variables you can see on a label, but it can also remove variables you were benefiting from.
Two common backfires:
-
Very low mineral content Yeast and bacteria don’t “eat minerals” like food, but minerals support enzyme activity and overall fermentation stability. Extremely low mineral water can make fermentation feel less predictable, especially in a new starter where the microbial community is still assembling.
-
Different buffering behavior Water isn’t just pH; it’s also buffering capacity (often tied to bicarbonate). Very low-mineral water tends to have low buffering. That can change how quickly acidity shifts after feeding. Sometimes that helps (acidifies fast). Sometimes it hurts (sharp swings, different timing).
Also, “pure water fixed my starter” can be a coincidence: many people switch water at the same time they improve feeding consistency.
Real-life example: a baker uses RO water and notices their dough ferments a bit faster but also becomes more prone to over-proofing because timing windows feel narrower. Nothing “bad” happened—just a shift in fermentation dynamics and expectations.
Takeaway: Distilled/RO can work, but it can change fermentation rhythm and stability in subtle ways.
Key distinctions or conditions people miss
Most confusion disappears when you separate: (1) starter vs dough, (2) chlorine vs chloramine, and (3) “minerals” into specific types with specific effects.
Starter vs final dough: water affects them differently (and at different times)
A starter is a small ecosystem you’re trying to keep stable across feed cycles. Final dough is a one-time fermentation where strength, extensibility, and timing matter.
Water can affect a starter more when:
-
the starter is new or weak, so inhibition is proportionally larger;
-
feeds are small and frequent, increasing disinfectant exposure per gram of flour;
-
the jar is cold, slowing growth.
Water can affect final dough more when:
-
mineral extremes change gluten behavior (too tight vs too slack),
-
buffering alters acid build-up timing during bulk,
-
or sodium-heavy water (like from some softeners) interferes with expected dough feel.
Real-life example: a baker’s starter seems fine (doubles), but their dough is always tight and resists stretching. They blame starter strength. The hidden cause can be very hard water tightening the dough even though the starter itself looks healthy.
Takeaway: Starter performance and dough handling can point to different water issues.
Chlorine vs chloramine: same goal (disinfect), different behavior (and removal limits)
Both are meant to control microbes in public water systems. For sourdough, what matters is persistence.
-
Chlorine: more reactive, more likely to dissipate with time and air exposure.
-
Chloramine: more stable, lasts longer in pipes, often harder to remove by “waiting.”
This is why two bakers can report opposite experiences with “tap water” and both be right—because they are not actually using the same disinfectant system.
A practical mental model: if your tap water rarely smells like chlorine, it might still contain chloramine. Smell is not a reliable test for chloramine presence.
Real-life example: someone moves cities. Their old city’s tap worked fine for starters. In the new city, starters struggle repeatedly. The difference isn’t “tap water is bad.” It’s treatment type.
Takeaway: Tap water advice fails when it ignores which disinfectant is used.
Minerals aren’t one thing: calcium/magnesium vs sodium vs bicarbonate (buffering)
Not all minerals behave the same. Calcium and magnesium contribute to water hardness and can support enzyme activity, while bicarbonate affects pH buffering. Sodium-softened water is different—it replaces hardness minerals with sodium, which doesn’t provide the same functional benefits. That said, sodium isn’t inherently harmful; its impact depends on overall balance rather than being universally “bad.” When people say “minerals,” they often lump together things that act very differently.
-
Calcium and magnesium (hardness): can influence dough strength and fermentation consistency. Moderate levels are usually unremarkable or mildly helpful. Very high levels can make dough tighter and less extensible.
-
Sodium: often higher in softened water. Sodium doesn’t behave like calcium/magnesium hardness. It can change flavor and dough behavior and can be unhelpful when it’s replacing hardness minerals.
-
Bicarbonate (alkalinity / buffering): controls how strongly water resists pH change. High bicarbonate can slow early acidification in a new starter, which can change which bacteria dominate early on.
This is why “hard water” and “soft water” advice can miss the point. Two waters can have the same “total minerals” but behave differently if one is bicarbonate-heavy or sodium-heavy.
Real-life example: a home has a water softener. The water feels “soft,” so they assume it’s gentler for starter microbes. But softened water can be sodium-rich, and that can alter flavor and dough feel compared to the original hard water.
Takeaway: Which minerals you have matters more than “more minerals.”
What assumptions does “alkaline water (pH 8.5) is better” rely on?
It assumes that starting with higher pH helps yeast and bacteria “get going.” The hidden assumption is: the starter needs help being less acidic.
But early sourdough success often depends on the opposite: a timely drop in pH that discourages unwanted microbes and helps lactic acid bacteria establish. If water has high alkalinity (buffering), it can resist that drop, especially in the first few days of a new starter.
Also, pH printed on a water report (or label) is not the whole story. Flour chemistry and buffering often dominate after mixing. Two waters with the same pH can behave differently if their bicarbonate levels differ.
Real-life example: a baker uses alkaline water for a brand-new starter. Day 2 smells off and activity is sluggish. They think the culture is “weak,” but the early environment may be staying less acidic longer, changing which microbes win early.
Takeaway: High pH sounds helpful, but buffering can delay the acid shift starters need.
“If X → then Y” flowchart for water type, treatment, and likely effects
-
Does your tap water smell strongly of chlorine today?
-
Yes → Your starter or dough may ferment more slowly today → consider reducing chlorine exposure if needed
-
No → Move to the next check
-
-
Is your water system treated with chloramine?
-
Yes / Not sure → Letting water sit may not remove it → consider proper dechloramination methods
-
No → Letting water sit may help reduce chlorine
-
-
Is your water very hard or very soft?
-
Very hard → Dough may feel tight or tear easily; fermentation timing may shift
-
Very soft / RO / distilled → Fermentation may feel less stable; timing windows can change
-
-
Is your water softened (sodium-based)?
-
Yes → Higher sodium may affect flavor and dough texture; it’s not the same as beneficial minerals
-
No → Move to the next check
-
-
Are you troubleshooting a NEW starter (days 1–4) or a MATURE starter/dough?
-
New starter → Disinfectants and buffering effects are more noticeable
-
Mature starter / dough → Temperature, feeding, and schedule usually have a bigger impact
-
Takeaway: Match the water concern to the specific “if-then” that fits your situation.
Real-world situations that change outcomes
Even “perfect” water won’t fix an underfed starter in a cold kitchen. And “imperfect” water often works fine when everything else is solid. This section is about why people get different results with the same advice.
Why does best water for sourdough bread behave differently in real life?
Because sourdough is a system with multiple sensitive points:
-
Temperature controls growth rate more strongly than most water differences.
-
Feeding ratio and timing determine whether microbes outcompete each other.
-
Flour choice changes minerals, enzymes, and microbial load.
-
Water treatment can change suddenly without you doing anything.
So a water change can “work” for one person and do nothing for another. They are not in the same system state.
Real-life example: two friends use the same municipal water. One has a warm kitchen and feeds at consistent intervals. The other keeps the jar near a cold window and feeds “when they remember.” The second person blames water; the first never thinks about it.
Takeaway: Water effects are real, but they are often smaller than temperature and feeding effects.
New starter days 1–4 vs mature starter maintenance: early pH shifts and LAB assembly
Days 1–4 are special because the culture is not “a sourdough starter” yet. It’s a changing mix of microbes from flour and the environment. Early on, you often see:
-
brief activity from organisms you won’t keep long-term,
-
then a quiet phase,
-
then a more stable rise pattern as acid-tolerant lactic acid bacteria establish.
Water matters more here because:
-
Disinfectants can slow early growth when populations are small.
-
High buffering (bicarbonate) can delay the acid shift that helps stabilize the community.
Once mature, your starter is less fragile. Feeding refreshes the environment, and the established community tends to reassert itself.
Real-life example: a new starter “dies” on day 3 (no bubbles). The baker assumes chlorine killed it. But day 3 is often a normal quiet stage. If they keep feeding on schedule at a warm-enough temperature, it often returns without any water change.
Takeaway: Early starter behavior is not a clean test of water quality.
Local water supply swings: seasonal disinfectant changes, construction flushes, “treated with chloramine”
Municipal water is not chemically constant. Things that can change:
-
switching between chlorine and chloramine seasonally,
-
temporary increases in disinfectant after contamination risk,
-
hydrant flushing or construction work that stirs sediment and changes smell/taste,
-
source-water changes (surface vs groundwater) that shift minerals and alkalinity.
For baking, the key is that your “normal” water might not be normal this week. If you notice a sudden change in smell, taste, or starter/dough timing, think “water event,” not “I forgot how to bake.”
Real-life example: a baker’s dough is consistently 1–2 hours slower for a week, then returns to normal. That pattern often matches a temporary treatment or supply shift more than a permanent “bad water” problem.
Takeaway: Sudden fermentation changes can reflect temporary water treatment swings.
Well water and water softeners: minerals, iron/sulfur odors, and sodium-heavy softened water
Well water can be great for sourdough, but it’s more variable and can come with extras:
-
Very high hardness (calcium/magnesium) can tighten dough.
-
Iron can affect taste and can signal broader mineral load.
-
Sulfur odors don’t automatically mean “unsafe,” but they can affect flavor and indicate different chemistry.
-
Softened water often swaps hardness minerals for sodium, which changes dough behavior and flavor differently than calcium/magnesium.
If a household has both softened and unsoftened taps, the two waters can behave very differently in dough even though both are “from the same well.”
Real-life example: a baker uses softened water for convenience. Their bread tastes slightly saltier than expected and the dough feels different day to day. The recipe didn’t change—the sodium contribution and mineral swap did.
Takeaway: Well and softened water can be fine, but they can shift dough feel more than city tap.
What this understanding implies for later decisions
Once you stop treating water as a moral choice (“tap bad, pure good”), you can troubleshoot faster. The goal is to identify when water is actually the limiting factor.
Before changing your water, focus on what matters more: temperature control, feeding schedule, and flour consistency. These factors usually have a much bigger impact on sourdough performance. When troubleshooting, change only one variable at a time—otherwise it becomes hard to tell whether water quality is actually affecting your fermentation.
How to tell whether water is the constraint (vs feeding, flour, temperature range, or timing)
Use a “big levers first” mindset:
Water is less likely the constraint if:
-
your starter rises and falls predictably,
-
dough ferments normally when temperature is controlled,
-
and problems disappear when you warm the environment or adjust feeding ratios.
Water is more likely the constraint if:
-
you repeatedly fail to establish a new starter (days 1–7) despite warm temps and consistent feeds,
-
your tap water has a strong disinfectant smell,
-
your city uses chloramine,
-
or your water is extremely hard, extremely soft, or sodium-softened and dough feel is consistently off.
A simple real-life test is consistency: if a problem appears only on certain days, suspect temperature swings or schedule first. If it correlates with water smell/taste shifts, then suspect water events.
Takeaway: Treat water as a “check” after temperature and feeding, not before.
What numbers matter when you check water quality: ppm hardness bands (e.g., ~50–150 ppm “moderate”), extremes, and warning signs
If you look at a water report, don’t get lost in every line item. For sourdough, the useful numbers are:
-
Hardness (as CaCO₃, ppm):
~0–50 ppm: soft
~50–150 ppm: moderate (often uneventful for baking)
~150–300 ppm: hard (can start changing dough feel)
300 ppm: very hard (more likely to tighten dough noticeably)
-
Alkalinity / bicarbonate (often ppm as CaCO₃):
-
Higher alkalinity means stronger buffering and slower pH movement, which can matter in new starters.
-
-
Disinfectant type: chlorine vs chloramine (often stated in municipal reports).
Warning signs that matter more than a specific ppm:
-
sudden strong chlorine odor,
-
repeated starter trouble in early days despite warm, consistent feeding,
-
persistent tight/tearing dough that doesn’t match flour and hydration.
Takeaway: Moderate ranges are usually fine; it’s the extremes and treatment type that matter.
When “remineralized RO water” is functionally different from RO/distilled (and why that distinction matters)
RO and distilled water are low in dissolved minerals. “Remineralized” water is not just a marketing word; it describes a different chemistry: minerals are added back, changing hardness and buffering.
Functionally, that means:
-
fermentation may behave more like it does with moderate mineral tap water,
-
dough strength and extensibility may feel more familiar,
-
and pH changes may be less “swingy” than with ultra-low mineral water.
The key distinction is not “RO vs not RO.” It’s mineral and buffering profile after treatment.
Real-life example: two bakers both say “I use RO.” One struggles with timing and starter consistency, the other doesn’t. The difference can be that one is using very low-mineral RO water, while the other is using water where minerals were added back, making it behave closer to moderate tap water.
Takeaway: “RO” doesn’t tell you enough; mineral/buffering level is what changes behavior.
Where water choice matters a lot vs where it’s usually noise (and why float tests/age myths often mislead)
Think in zones:
High impact zone (water can be the bottleneck)
-
Brand-new starter (days 1–4), especially in cool kitchens
-
Tap water with strong disinfectant smell
-
Known chloramine treatment with no dechloramination
-
Very hard water (>300 ppm) causing tight dough
-
Sodium-softened water changing flavor/dough feel
Medium impact zone (water can nudge outcomes)
-
Mature starter that is occasionally sluggish
-
Dough that is borderline over/under-proofed where timing is tight
-
Water with high alkalinity buffering early acid changes
Low impact zone (water is usually “noise”)
-
Mature starter with consistent rise/fall
-
Dough fermentation issues clearly tied to temperature/schedule
-
Situations where flour choice, feeding ratio, or dough temperature changed
Common misleads:
-
Float test: a sinking starter can still bake fine; it’s not a water diagnostic.
-
Starter age myths: age doesn’t override current feeding and conditions; water issues won’t be fixed by “older starter.”
Takeaway: Water matters most at the edges—new starters, extreme chemistry, and treatment swings.
Common misconceptions about best water for sourdough bread
-
Tap water ruins sourdough → Most tap water works; problems are situational (treatment type, extremes, or early starter stage).
-
Letting water sit removes all disinfectants → It can reduce chlorine, but often does little for chloramine.
-
Distilled/RO is always safest → Very low-mineral water can shift fermentation stability and timing.
-
More minerals always mean better crust → Moderate minerals can help; extremes can tighten dough or change timing.
-
Alkaline water is better for starter growth → Higher buffering can delay the early acid shift that helps starters stabilize.
FAQs
1. Does chlorine kill sourdough starter?
Chlorine doesn’t always instantly kill a sourdough starter, but the chlorine effects on sourdough are very real—it can weaken yeast and beneficial bacteria over time. Since chlorine is designed to disinfect water, it also slows fermentation, leading to fewer bubbles and poor rise. This directly impacts overall bread baking water quality and starter performance. If you’re aiming for the best water for sourdough bread, it’s better to use filtered water or let tap water sit overnight so chlorine can dissipate naturally.
2. Should I use RO water for sourdough?
Using RO water for sourdough is a mixed bag. It removes chlorine and contaminants, which is great, but it also strips away minerals that yeast needs. For optimal fermentation, many bakers prefer remineralized RO water, which adds back essential minerals like calcium and magnesium. Compared to tap water vs filtered for yeast, RO water is cleaner but may need adjustment. If you want the best water for sourdough bread, slightly mineralized or filtered water tends to give more consistent results.
3. Why is my sourdough starter not rising with tap water?
If your starter isn’t rising, the issue could be tap water vs filtered for yeast performance. Tap water often contains chlorine or chloramine, both of which negatively impact fermentation and overall bread baking water quality. These chemicals can suppress yeast activity, making your starter sluggish or flat. Switching to filtered water or properly treated water can significantly improve rise and help you achieve the best water for sourdough bread conditions.
4. Can I use boiled water for bread making?
Yes, boiled water can be used for baking—but only after it cools completely. Boiling helps reduce chlorine, improving bread baking water quality, though it won’t fully remove chloramine for baking. If your goal is optimizing fermentation, boiled water is better than untreated tap water, but filtered water is still the more reliable option. In the tap water vs filtered for yeast comparison, filtered water typically delivers more consistent baking results.
5. Best water pH for yeast fermentation?
The ideal pH for yeast fermentation is slightly acidic to neutral (around pH 6–7), which supports both yeast and bacteria activity. This balance is key when choosing the best water for sourdough bread, as extreme pH levels can slow fermentation or affect flavor. Good bread baking water quality usually falls within this range naturally, especially when using filtered or balanced mineral water.
6. Do I need minerals in water for bread crust?
Yes, minerals are essential for structure and crust development. Using mineral water for crust can improve gluten strength, leading to better oven spring and a crispier finish. Water that lacks minerals—like pure RO water—may produce weaker dough unless it’s adjusted. That’s why many bakers prefer remineralized RO water or naturally mineral-rich water when aiming for the best water for sourdough bread and superior crust quality.
7. How to remove chloramine from baking water?
Unlike chlorine, chloramine doesn’t evaporate easily, so letting water sit won’t help. The most effective way to remove chloramine for baking is by using a high-quality carbon filtration system. This significantly improves bread baking water quality and supports better fermentation. If you’re comparing tap water vs filtered for yeast, filtered water is the clear winner when chloramine is present.
8. Does hard water affect bread texture?
Yes, hard water can affect dough handling and final texture. Its high mineral content can tighten gluten, sometimes leading to denser bread. While some minerals are beneficial (as seen in mineral water for crust), too much can reduce rise. Balancing hardness is key to achieving the best water for sourdough bread. In many cases, filtered or remineralized RO water provides a more controlled mineral level for consistent baking results.
References