Baking Steels Vs. Baking Stones

Ok, so you make your dough, it's moist, it has living yeast that raised the dough during proofing, and the moment you put it in the oven, a whole bunch of stuff happens.

On the outside, the crust warms up, expands, transfers some heat into the crumb, but ultimately dries out, then hardens. Meanwhile on the inside, the increased heat initially encourages faster carbon dioxide (CO2) gas production from the still living yeast, (at least until it gets hot enough to kill the yeast) it also turns that dough's moisture into steam, and the increasing temperatures expand both the gas and steam even further. Creating bubbles in the dough, and expanding the loaf before it hardens.

So there's a race going on, specifically between the expansion of the crumb, and the drying/hardening of the crust.

If you place a dough ball on a cold surface during the bake, that initial rise of the crumb in the oven will be delayed allowing the crust to harden first, which restricts that expansion. This renders a denser bread with less height. This is generally considered "not ideal"... especially if you like light airy bread with tall slices. (Not all recipes have this goal).

Alternatively, if you put it on a preheated hot surface, whether it's stone or steel, the entire base is immediately heated up without hot air being blown around it, and the moisture in the base isn't able to easily escape, which facilitates faster heat transfer into the crumb (inner part of your dough) from the stone/steel.

Warming the core of the dough sooner, increases the height of your loaf breads by getting heat and height into the crumb earlier in the baking process... notably before the crust/outer crumb is set that would slow it down. Meanwhile the sides and top of your loaf is still hardening, but is also expanded more before doing so, creating newly exposed areas of the dough, which allow further expansion... at least.. in tiger breads and it's ilk.

Curiously, pizzas and other topped flatbreads, also benefit from baking stones and steels because the heat applied to the base from the hot surface, cooks the dough faster (given it's so thin), and this shortens the overall bake time, and stops your toppings from getting overcooked. Win win!

Materials matter!

Now, preheated stones/steels have two key characteristics that alter the bake:

1. Thermal conductivity: How quickly the material absorbs heat, how quickly it distributes heat within it's mass, (for even heating) and ultimately transfers that heat to the food.
2. Thermal retention: How much heat the material can absorb, which impacts how long it takes to heat up, and cool down.

Let's discuss thermal retention first!

Imagine heat is like water. If you pump the heat from a bucket with a domestic sized pump... it'd last mere seconds then run out. Now imagine you have a whole Olympic sized swimming pool... that'd take days to fill up (heat up) and drain (cool down). A material with lots of heat retention is like the swimming pool, and a material with very little, the bucket.

However, the rate of pumping also plays a part. That brings me to thermal conductivity.

Ok, so if you had a standard garden hose, that maxes out at 20L (4.4 gallons) per minute, your 2500 cubic metre Olympic Pool drains in 86.8 days. What if we use a fire truck, capable of pumping 7500L per minute? It drains in just 5 hours, and 33 minutes.

Baking stones have relatively high retention (capacity), but relatively low conductivity (transfer speeds). This is the swimming pool, but garden hose analogy. Whereas baking steels are the opposite, with relatively high conductivity (fire truck transfer speeds), but relatively low capacity (bucket), and no steel can provide more heat than it has. (Although it charges up much more quickly from the oven... but not quite as fast from oven air, as the steel transfers to the dough). Dough's a lot more dense than air.. so that accelerates the conductivity aspect.

How to get the best of both worlds?

Increased surface area, and thinner materials will increase thermal conductivity speeds. This will cut down on preheating time, and promote faster cooking, but limit overall heat retention. That said, it also accelerates the recharge, so it's not "all bad".

Whereas more mass/materials will increase retention, but slow the transfer of heat in/out, because the surface area (through which all heat is transferred in/out) is reduced, relative to the amount of material. This increases the time it'll take to burn the bottom, but also take longer to recharge. So this is why we preheat it for longer, to make sure it has plenty to give without relying on the recharge from the oven's hot air.

So you need to choose the appropriate thickness of the material to suit it's conductivity and capacity characteristics. However, baking steels being so heavy, may need to be made smaller/thinner in order to be easier to move around... so there are other considerations at play here.

Meanwhile, because baking stones are much less dense, you can make them thicker without impacting mobility, allowing them to have huge capacities, if you're willing to preheat longer.

Personally, I think stones are suited to thicker/taller breads with thicker/firmer doughs, using longer bakes with modest bread baking temperatures, because the stone is less likely to burn the bottom of your loaves, and evenly cook the bread.

My "ideal for stone bakes" cut-off list comprises of:

• You have the time (usually an hour) to preheat the stone
• Bakes longer than 30mins,
• Taller/thicker/softer loaves or the thicker and/or softer crust pizza styles.
• Temperatures between 180C-270C (356-518F) for bread, or anything above 300C/570F for pizza. However, higher temperatures need even longer pre-heat times.
• Multi-batch baking. (no recharge time needed since it only slowly loses heat)

The humble pizza stone has been around for a long time. Literally the stone age, in fact. While baking stones come in a variety of materials, most of them these days are synthetic. This makes the heat absorbtion and distribution more predictable and even, over more natural varieties.

Synthetic stones usually comprise of a ceramic base or even a ceramic infused with crushed up rock. This often leaves a sandstone texture on the coarser models, a concrete texture in the middle, and ceramic, even glazed ceramic coatings on the smoother end. You don't want a really rough texture as that can lead to excessive sticking, this makes it harder to clean.

That said, you don't want to make it too smooth because then your pizza can slide off the edge very easily leading to messes in the oven or worse yet... the entire pizza falling to the floor. So even the glazed models have a less-than-glasslike texture to prevent such problems, while keeping things relatively easy to clean.

Pizza stones aren't perfect though. They have superior heat absorption, but comparatively less heat conduction.. meaning it takes longer to heat up and cool down... also it's possible that even synthetic stones can have hot and cold spots (well, hot, and hotter spots) because that conductivity isn't evening things out.

Obviously, pizza stones won't rust, and many are dishwasher safe... but they will break if dropped, and often crack if heated/cooled too quickly and/or unevenly.

Honestly, I think stones are better in oven-like situations, the heating is slower and more even so there's less chance of cracking, and they work especially well in heat deflectors in lidded charcoal/wood fired barbecues, they won't warp or rust which makes them a good low maintenance option.

The baking steel, is both incredibly accurate, yet misleading at the same time. When you think of steel cookware, you probably think stainless steel, like your pots, or your frypan, or your utensils... this is completely understandable. However, baking steels are rarely stainless. In fact, it's arguable, that stainless isn't as good as a trusty carbon steel for baking purposes.... although this does depend on the variety of stainless steel, the variety of non-stainless it's compared to, and of course, baking preferences/styles/recipes being implemented.

I found about fifty varying styles and companies selling baking steels, and only two claimed to use stainless. The rest use a "seasoned" carbon steel. Now when I say seasoned, I'm not talking about adding salt to a meal, I mean baking thin layers of oil over the steel (as you would with non-enamelled cast iron cookware) in order to prevent rust, and create a non-stick-like surface.

So this needs style of steel needs routine maintenance, is not dishwasher safe, but it won't crack, or chip, or really care much if you accidentally heat or cool it too much or too quickly.... Though, it might dent if you drop it.. but it will sever your toes off if you drop it edge-on.. and your floor (regardless of tile, or concrete base... will have damage. Furthermore, the increased density of steel makes these much heavier than the stone. So if you are of an elderly, or injured state... this can pose significant issues....Unless you leave the steel in the oven on a near-permanent basis. Which I have heard done from my fellow bread baking enthusiasts.

What makes a steel quite so attactive to some bakers, is that heat conductivity works really well with getting the crispiest pizza crusts, especially when paired with a thicker steel which helps to offset the lower heat retention of the metal. Of course, heating more metal... that increases the preheating times. Obviously.

My "ideal for steel bakes" cut-off list comprises of:

• You have little time (usually only an 30mins) to preheat the steel.
• Bakes shorter than 20mins,
• Thinner, crispier pizza bases/breads are your "usual bakes"
• Temperatures above 270C/428F)
• single-batch baking. (The steel might need 10 mins to reheat between batches if left in the oven, another 30mins if pulled out with the pizza)
• Alternatively, a low baking temp like 180C/356F and mid-range bake duration (20-30mins) should offset the high conductivity issue for some breadlike-pastries.

Now, you can use either stone or steel and get great results. You can even adjust the way you bake and "break the rules" by using the less-ideal one... but I don't think there's any hard and/or fast rules here. Try things for yourself (even borrow) whatever gear you don't have, or improvise a steel or stone if you have the option. Compare the results and process and make a decision that suits your needs. Just make sure that you keep any improvised cookware food safe, ok?

Of course, there are going to be "team stone" and "team steel" fans/zealots. I don't want to devalue what anyone uses... especially if they're happy with it. I baked with a stone for years before I got my steels and got great results. That said, there's a few things like thin crust pizzas (not that I'm an exclusive fan) that work well on the steel... just that little bit more reliably if not easier as well.

I think it's harder to break a steel, but... I do think the stones are much lower maintenance, and easier/cheaper to get... generally because they're so ubiquitous. I also think stones are suited for people with limited strength, so regardless of baking pros/cons... these are real considerations.

That said, I can put the steel over an open flame, and even temporarily replace/expand my barbecue's cast iron hot plate if I wanted to.... even sit it on my stove's gas hob, and cook with it like a griddle, fry eggs and bacon on it... (if I keep an eye on the running fat/oils.. because I don't have a groove to capture all that before it runs off the edge). There's no way I could do that with a pizza stone without cracking it due to the uneven heating.

While my three stones and two steels all work well... there's definitely a difference in finished product when you bake with both. There are cases where either has "an edge" or "a slight disadvantage".. but there's an awful lot of fun stuff you can do with either.

However, can I leave one final thought with you?

You might even have, or are considering getting, a stone or steel. Many stones (and this steel) aren't expensive, and can do something.... a little special when combined in creative ways with gear you probably already have.. but first, look at this Challenger Pan....

What if you have a pre-heated dutch oven... flip the main body of the dutch oven (no lid) upside-down, and cover a dough that you placed on either a hot stone/steel... that would make a dirt-cheap "domed" loaf pan alternative... (much cheaper than the "Challenger Loaf Pan")

It works for me, and I think some readers out there might want to try it. Particularly if you don't already have something similar... because... why limit yourself to just a steel or stone, when you can have a steel/cast iron or stone/cast iron combination?
  

Did I just disrupt the two way debate with a third and even fourth option? Mwahahaha. (BTW, I'm not sorry for thinking "out of the box"). Honestly, it's so nice when I can add something to topics many other sites have discussed.

Thank you for dear reader, for making it this far. I hope it helps.

All the best with your baking! Stay safe, and have fun with delicious baked goodness!

Ham.