Breadmaking 101: All About Proofing and Fermentation

A close up of two slices of artisanal bread, with the rest of the loaf in the background.
Photographs: Vicky Wasik

Hello bakers! And welcome back to Breadmaking 101. If this is your first time coming across the column, check out our introductory post where you'll get the big picture on what we're working on and meet the four stages of bread-making: mixing, proofing and shaping, baking, and, of course, eating and storing bread.

In our previous post, we talked all about mixing the workhorse loaf, and gave ourselves a primer on the chemistry at work when we take flour, water, salt, and yeast, and combine them to make dough.

Today, we're going to delve into what happens when dough is rising, and get to know our soon-to-be good friends—the billions of yeast cells that make our wet blobs of dough into pillowy, airy wonders—a little better. Along the way, we're going to unpack what it means to divide and shape dough, and figure out how we can confidently and purposefully coax our dough into loaves, hopefully without making too much of a mess of ourselves.


When we last left off, we'd just finished mixing our dough and transferred it into an oiled container. This is where our dough will perform its first rise, or bulk fermentation. (This can also be called its bulk proof). But what is fermentation? And what is proofing? And what is a baker to do while all of this is happening? While our dough is rising, and before we perform our folds, let's take a minute to talk about the basics of rising, and the vocabulary to discuss them.

All About Yeast

Fermentation, at it's core, is all about yeast. Yeast are a kind of fungus, single-celled and ubiquitous. Although there are over 1,500 distinct species of yeast and many more strains (which range from helpful to hurtful), when we bake bread, we are almost always using Saccharomyces cerevisiae, whose name we won't worry about trying to pronounce. Commercial baking yeast, whether we we're talking about fresh cake yeast, active dry, or instant, are all purified cultures of the same species. Different strains of Saccharomyces cerevisiae are also commonly used to brew beer, and specifically ales. When we choose what kind of commercial yeast to use for bread, it's important to remember that they're all the same species and strain. They will all go dormant at 40°F, and they will all die at 130°F during baking. Even so, let's quickly discuss the pros and cons of each commonly available type:*

  • Fresh Yeast (a.k.a. Cake or Block Yeast): Fresh yeast has the highest moisture content of the three varieties. This extra water means it's bigger, which makes it easier to measure. Also, since the yeast hasn't been rendered dormant through processing, it has more leavening power than active dry or instant yeast. Some people swear that it tastes better than other commercial yeasts as well, but I've noticed no differences in taste between fresh yeast and the others. Its chief draw-back is that since the yeast is in an active state already, it will spoil and die faster than active dry or instant, giving it a short shelf-life, generally not more than two weeks.
  • Active-Dry Yeast: Of the three types of commercial yeast available, active dry has the longest shelf-life—in a sealed container in the fridge it will keep for years. For a home baker, this makes active-dry yeast a good choice. However, the manner in which it's processed means that many of the yeast cells are already dead at the time they are added to the dough, i.e. you need to use more than the other two varieties to get the same rise. For doughs that are very heavily yeasted, some people find that the yeast debris in active-dry creates undesirable flavors. It also needs to be reactivated in water—i.e. bloomed—prior to being added to the dough. If you're impatient, like me, this annoys you even though it isn't a big deal and probably shouldn't.
  • Instant Yeast: Instant yeast requires no blooming and activates more quickly than active dry. This means that it can be added directly to our dough and we can be on our way. Also, it has a relatively long shelf life, and that shelf life can be extended by keeping it refrigerated. For a home baker, I believe instant yeast is the ideal choice.

*Note: Despite the differences in yeast potency described in the list above, the recipe posted for the workhorse loaf takes these into account. Whichever variety of yeast you buy, make sure to measure accurately and all will be fine. Sourdoughs and starters are another can of worms, and we'll cover them in later posts.

What Makes Bread Rise

Yeasted breads get bigger. That's why we call them leavened. For a baker, this is what we call rising. Rising is the most dramatic physical change a dough undergoes on account of yeast activity. Technically speaking, rising is a product of a process called respiration, which occurs in conjunction with fermentation, that we'll discuss next. You see, S. cerevisiae has a serious sweet tooth—think of it as a microscopic Cookie Monster. And flour just so happens to be packed with starches—long chains of simpler, smaller sugars, such as glucose, sucrose, and maltose.

When our flour met our water during the autolyse, enzymes called amylases began breaking down the flour's starches into these simpler sugars, which the yeast readily devour. As the yeast eat sugars released by the starch, they belch out carbon dioxide, and that gas congregates in tiny air bubbles. It's those same air bubbles that we incorporated into our dough during mixing. These bubbles are in turn held inside our dough by the gluten structure we developed during mixing, and which we'll further develop during bulk fermentation. More carbon dioxide + gluten = bigger, more open bread. As the yeast respirates, our bread rises.

Fermentation and Proofing Basics

In the simplest of terms, fermentation is what happens when yeast cells eat and poop. Specifically, it's what happens when yeast cells consume sugars and produce ethanol and other derivative chemicals. The alcohol produced by the yeast during fermentation—along with a multitude of other reactions—are what give great bread its characteristic flavors and aroma. Generally speaking, more fermentation means tastier bread. In the most technical, terms fermentation is an anaerobic reaction (meaning it happens in the absence of oxygen) that the yeast performs after respiration, which is aerobic and requires oxygen.

In bread baking, the word proofing most commonly refers to the final rise dough undergoes, which takes place after being shaped into a loaf, and before it is baked. In practice, however, the words proof and fermentation are sometimes used interchangeably. What's important to realize here is that shaping dough affects its physical form, but doesn't impact its internal chemistry—the processes and chemical reactions at work during our bulk and final rises are the same.

With that vocabulary in mind, let's take a look at the dough we all just birthed, and, armed with patience, get back to work.


The bulk fermentation for any dough is a crucial step in the bread baking process, even if it isn't the most exciting one. We call it a bulk fermentation because we are letting our dough—the entire batch—ferment as one mass, before dividing and shaping it into loaves. It's during our bulk fermentation that the yeast does the majority of its work, helping our dough gain flavor as ethanol and other byproducts are produced, and gain structure as CO2 inflates our gluten network.

At a comfortable room temperature, our bulk fermentation for the workhorse loaf will take about one-and-a-half to two-and-a-half hours. As a rule, warmer dough will rise faster than colder dough, so make sure you take stock of the environment in which you're baking.

I can hear you asking, "Why not make my dough really warm so it'll proof faster and I can have bread sooner?" There are several reasons we don't want to rush the bulk fermentation. Chief among them is that the fermentation that produces good flavor really only takes place in earnest after the yeast have exhausted most of their oxygen supply. If we allow our dough to rise too quickly, we'll get lots of CO2 but less alcohol than we want, meaning our bread won't taste as good. Furthermore, gluten is less temperature sensitive than yeast. Meaning that if we get our dough too warm, our yeast will inflate the dough faster than its gluten structure can organize itself—the bubbles that make up our dough's internal structure will over-inflate and pop like balloons. This will hurt our shaping efforts later and give us flatter, less sexy looking bread.

I know, two hours feels like a long time. Trust me, it's worth it. Don't rush the bulk rise.

So, can the bulk rise be slowed down? Yes. A slower bulk rise will encourage more flavor and structural development up to a point. But remember, the yeast has a limited food supply, and we want to make sure to leave it enough food for a successful final proof, and make sure enough sugars are present to allow our crusts to properly caramelize when we bake them. If you want to let you dough proof for longer, try bulk-fermenting it in a cooler place, but don't allow it to go longer than three hours or structure and flavor may be compromised.

For the workhorse loaf, a bulk proof of approximately two hours gives us the optimal balance of flavor and texture.

Practically speaking, all this means you shouldn't let the workhorse bulk-ferment anywhere you wouldn't want to hang out. If you're working in a really hot kitchen, allow your dough to bulk ferment in cool a cabinet close to the floor. If you're working in a very cold kitchen, put your stove on low and set your dough near it. If you live in a home where you can control the temperature of rooms without needing to beg your superintendant for a favor, set your thermostat to 75 degrees and stop thinking about it.

But a watched dough never rises, so don't stare at it the whole time. Eat a sandwich, make your bed, or get to work cooking the rest of your meal. Let the dough do the work and try not to mess with it too much. Distractions are a home-baker's best friend.

Folding and Dividing the Dough

That said, us bakers do have some important work to do during the bulk fermentation. About a half hour into the bulk rise, it's time to fold, or turn, our dough. Folding dough effectively takes a bit of practice, but is one of my favorite parts of making bread. A good fold lets us stare into a dough's soul.

So, why do we fold dough? Lots of reasons. To start with, folding dough develops gluten structure. By first stretching and layering our gluten, we help our dough more effectively hold water and air. As we trap more air in our dough during these motions, folding also helps to establish a more open crumb structure in our baked loaves. Secondly, folding dough redistributes our yeast and its food, making sure each little Cookie Monster gets its fill. Also, folding dough helps to regulate its temperature, keeping it consistent through its mass. Together, these two consequences of folding regulate yeast activity, and help our dough stay on schedule.


To perform a fold, start by wetting your dough spatula and hands with water. Then, gently scrape around the edges of the bowl to prevent sticking, and make a clean fold possible. Without tugging, pull the side farthest from you up and towards you, and fold your dough in half. Give the bowl a quarter turn, then perform the same motion again. Give the bowl a half turn, and repeat the same motion. Lastly, pull the unfolded side of your dough carefully up from the bottom, and pull it up and over to form a neat package, like so. All the while, allow the dough to stretch itself—your hands are just assistants. Performing these motions too aggressively may tear the gluten, making the process counter-productive.

The dough should now feel taught but pillowy, and have a spring to the touch. Also, you'll notice that the dough is far less sticky than before, mostly because gluten is AMAZING, and does all sorts of useful things with water and air. Re-cover the bowl and have a cocktail.

Our second fold will be performed about half an hour later, when the creases from our first fold have melded together, showing us that our gluten network has relaxed and is ready to be re-stretched. With this second fold we want to be very careful not to push too hard on our dough, or we might de-gas it and undo a lot of the work done by the yeast and ourselves thus far. Don't shake the baby—every bit of gas counts. In the event you do squash your dough a bit, don't worry about it too much. Just be extra careful during shaping to treat your dough gently. These things take practice. You will still have delicious bread. Re-re-cover the bowl and have another beer, or two, cause it will be most of an hour before we disturb our dough again.

Check your dough after another 45 minutes or so. Wet your hand and gently push on the dough surface. Feels dense? Go watch the Daily Show, and come back in a half hour. More rising time is just fine so long as we don't just up and forget about it. Feels really dense? Move it to a warmer part of your kitchen. The dough should feel like a waterbed, pillowy and with some spring, but your finger should leave a slight imprint. Is it there yet? Good. You're ready to divide the dough, which is the first step towards shaping your very own loaves.

To divide the dough, lightly flour the top with AP flour, scrape around the sides with your dough spatula to free it from the bowl and quickly flip the bowl upside down. The dough should flop out in one large blob, and what was at the bottom of the bowl should now be on top. It'll also be really sticky. This is good, like so:


Lightly flour your hands, bench knife, and the counter top on which you will be shaping. With your bench scraper, decisively cut the dough in half, pushing the halves away from each other with the bench knife, making sure to keep the bench knife's blade firmly flush with your counter's surface.


Pre-Shaping and Bench Resting

Pre-shaping is all about giving your dough a heads-up about what shape it's going to be later, and giving the gluten a little time to get situated. Think of it as a dress-rehearsal for the big show. For us, our final shape is going to be round—a boule—and so our pre-shape is going to be round as well.

To pre-shape, we're going to perform a series of folds similar to what we did during the bulk rise. We want to do this in as few motions as possible, making those motions decisive and clean, without being aggressive. It'll look something like this:


Once you've folded your dough into a neat little package, gently flip it over with your bench knife to let the smooth side face you. For the moment this is the top of our loaf-to-be. The place where the different sides of the dough meet and meld is our seam, which should end up on the bottom. Like this:


Most important here, is to not over-think this. Just try to get some tension on the surface of the loaf. If we mess with it too much now we're just going to push our hard-earned gas out of it. Pre-shapes—like rehearsals—aren't meant to be perfect. Lightly flour the tops of the rounds and cover with a towel.


Allow the pre-shaped loaves to hang out on the bench for a while—anywhere between fifteen and forty minutes will do the trick. By letting the tension we built during our pre-shape relax, we'll be able to create even more tension during our final shape, all without tearing the surface of the loaf. This helps make big, beautiful bread. This is our bench rest.

Prepping the Proofing Basket

While this is happening, we should ready our proofing baskets or bowls, which will help support the structure of our loaves during their final proof. Start by choosing something the right size. These are going to be big loaves of bread, but we don't want to get crazy. The proofing baskets—called bannetons—that I use at home and at The Cleveland are made specifically for 1.5-2 lb. loaves of bread. If you don't have bannetons use a medium serving bowl or colander, the size vessel you might use to serve potatoes for four during dinner. Once shaped, our loaves should fill the basket a little more than halfway, which will leave adequate room for the final rise.


To ready your baskets, choose two large kitchen towels made of smooth cloth. Don't use anything fuzzy unless you plan to eat that fuzz—it will stick to the bread. Using rice flour (although plain old AP flour will work fine, just go a little heavier), brush the towels with a light-to-medium coating of flour. We don't want to go too light or the loaves will stick; too heavy and we'll be eating clumps of burnt flour off our crusts. Place the towels in the proofing baskets or bowls and go about your business.

Final Shaping and Proofing

We're making what's called a boule: a big, round loaf. That means that our final shape will be the same as our pre-shape. We know our loaves are ready for final shaping when giving a gentle tug on the rounds shows some stretch and does not immediately pull back. Take a look:


Once our dough has shown us that it's ready to be shaped, flip the rounds so the seam side is now facing up again, and once again perform the folds listed above, gently developing tension along the rounds' surface. Use flour to keep the dough from sticking to you and the bench, but not so much that the dough won't stick to itself. Too much flour will keep our seams from holding, or will show up as clumps of unincorporated flour after baking. It's best to just flour your hands and scrape underneath the loaves with your bench knife to prevent sticking. Once you've folded your dough appropriately, cup your hands together and pull the dough towards you to generate tension along the boule's exterior, rotating the boule a quarter turn between pulls. Like with the pre-shape, we want to use as few motions as possible.


If the dough surface begins to rip, you're pulling a little too hard. It's not a disaster. Just stop. Remember: We're proofing our boules in round containers. All the little imperfections will smooth out there. Even more to the point, shaping bread isn't fine art. We're going to eat it. Shaping is about tension and structure, not aesthetic perfectionism.


Let the rounds rest seam-side-down for just a minute or so to make sure the seam holds together. Then, using your bench scraper with a quick, firm motion, flip the boules carefully into the baskets, making sure the seam side is facing up. What's facing up in the basket will become the bottom of our loaves once they're baked.

Cover the boules in the baskets with towels and place them in the fridge, where they will undergo their final fermentation, or final proof. During this time, the loaves should nearly double in size. Proofing our loaves in the fridge (also called retarding) will slow down their final rise, giving our loaves more flavor. Also, retarding loaves during their final proof makes them easier to handle and score before baking, which will improve the crumb, crust, and appearance of our baked loaves.


And with that, it's time to begin preheating our ovens and talk about how to bake all of this hard work into something beautiful. But that conversation will have to wait until our next installment, which will be all about baking and scoring.

Happy proofing everyone! And keep the questions coming.

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