Tangzhong in sourdough bread: does it make a difference?

Tangzhong, an Asian technique designed to enhance the softness of yeast bread and extend its shelf life, is being embraced by a small but growing number of bakers. Over the past year we’ve covered the various uses of tangzhong in this blog. Yes, tangzhong is the key to softer sandwich loaves and dinner rolls with better freshness. Yes, it works with whole grains; and you can apply it to most of your favorite yeast recipes, once you understand how it works.

Tangzhong in sourdough via @kingarthurflour

But what about tangzhong in sourdough bread? Does it give the typical sourdough loaf a softer crumb, and allow you to enjoy fresh-tasting bread for days longer?

First of all, let’s take a step back and think about this. Many sourdough breads are crusty and chewy; that’s a large part of their allure. Do you really want to use tangzhong to soften them up?

Also sourdough breads, particularly those naturally leavened (without commercial yeast), already have an incredibly long shelf life. How much use would it be for tangzhong to potentially extend that shelf life from, say, 10 days to 12? To me, it sounds like using tangzhong in sourdough bread might be a case of carrying coals to Newcastle.

Still, enough of you have asked about tangzhong and sourdough that it was worth trying. And based on my week of experimenting with three different sourdough bread recipes, I can safely say that tangzhong made no difference in the texture of those breads: the soft rolls weren’t any softer, and the crusty bread remained crusty. In addition, tangzhong didn’t extend the shelf life of any of the breads I tested.

Are you a passionate bread baker who wants to try the tangzhong technique with sourdough? Let's chat about that. Click To Tweet

You may want to stop reading right here; the question’s been answered. But if you’re interested in the details of my experiments — and why I believe tangzhong doesn’t seem to produce any effect in sourdough bread — read on.

Tangzhong in sourdough via @kingarthurflour

The recipes I choose to test are Buttery Sourdough Buns, enriched with butter, sugar, and egg; Basic Sourdough Bread, a “lean” (no fat) yet fairly soft sandwich loaf; and Naturally Leavened Sourdough Bread, a crusty artisan-style loaf baked without commercial yeast.

If you aren’t familiar with tangzhong, I highly recommend reading our Introduction to tangzhong. In the meantime, here’s the short version: Tangzhong involves cooking a small percentage of the flour and liquid (water or milk) in a yeast recipe very briefly before combining the resulting thick slurry with the remaining ingredients.

This cooking encourages the starch in flour to absorb more liquid, which it subsequently holds onto throughout baking and cooling. The result? Bread with more moisture, which translates to a softer crumb and longer shelf life.

Tangzhong in sourdough via @kingarthurflour

First test: Buttery Sourdough Buns

To start, I need to get my refrigerated starter up to snuff. A couple of feeds and it’s bubbling nicely.

Tangzhong in sourdough via @kingarthurflour

Next, I make dough the standard way, not using tangzhong. The dough is soft but not sticky — see how it clings to the side of the bowl?

Tangzhong in sourdough via @kingarthurflour

Then I start my tangzhong loaf by cooking up a flour/water slurry, using part of the flour and water in the recipe.

Tangzhong in sourdough via @kingarthurflour

Once the slurry cools slightly, I combine it with the remaining dough ingredients to make a soft dough almost identical to the original non-tangzhong dough.

This takes a bit of tweaking with the amount of water. Since the slurry absorbs some of the liquid in the recipe, it’s usually necessary to increase the liquid overall to maintain a soft dough — which is what I did, adding a couple of tablespoons additional water (more on that later).

I let the two doughs rise, shape them into buns (with a buttery swirl), let them rise in the pan, then bake.

Tangzhong in sourdough via @kingarthurflour

The finished buns aren’t very brown; I want them to remain soft, so I underbake them just a tiny bit. Despite their rather wan appearance, they’re richly flavored, with a noticeable hint of sour overlaid with butter’s distinct richness.

Once they’re cool, I taste a bun from each batch. Both are equally tender and moist.

Tangzhong in sourdough via @kingarthurflour

I wait a few days, taste-test again. Same result.

At the one-week mark, both batches of buns are remarkably fresh-tasting. It’s not until day 10 that I start to notice some dryness. But throughout, I can detect no difference between the texture of the standard vs. tangzhong buns.

Next up: Basic Sourdough Bread

This sandwich bread recipe calls for 2 cups of sourdough starter, double the amount I’d typically use for the single loaf this produces. Let’s see what happens.

Tangzhong in sourdough via @kingarthurflour

In order to create the 4 cups of starter I’ll need (2 cups for the standard loaf, 2 cups for the tangzhong version), I  build the starter’s volume over the course of a couple of days. That means transferring it to my Big Green Bowl. (I know each one of you has a favorite big bowl; this fluorescent melamine monster is mine.)

Tangzhong in sourdough via @kingarthurflour

I let the doughs rise, shape them into loaves, and place them in pans.

Tangzhong in sourdough via @kingarthurflour

Looks like I didn’t position this loaf’s seam on the bottom of the pan, or perhaps didn’t give it enough of a second rise — which are a couple of reasons bread can split while baking. Oh well, beauty is only crust deep, right?

A couple of hours later — bread! That’s the tangzhong loaf in front, the standard loaf behind.

Admittedly not the most beautiful loaves I’ve ever crafted, they’re nonetheless quite tasty: crusty on the outside, moist within, with an interesting “springy,” sponge-like texture. This is due to the lack of fat; I wanted to see if sourdough bread made from a lean dough (no added fat) would benefit from the tangzhong treatment.

Again, I taste the bread the day it’s baked, then at subsequent intervals up to 10 days.

Tangzhong in sourdough via @kingarthurflour

And again, much as I want to (I love my tangzhong!), I can never detect any difference in texture.

The final test: Naturally Leavened Sourdough Bread

For my last test, I choose a recipe without any added yeast. Including just sourdough starter, all-purpose and whole wheat flours, water, and salt, this bread at its best is crusty, chewy, and riddled with irregular holes.

Tangzhong in sourdough via @kingarthurflour

I make the dough; that’s standard dough on the left, tangzhong-enhanced on the right. Again, notice how similar their texture.

Tangzhong in sourdough via @kingarthurflour

The recipe makes two large loaves, but I decide instead to make one loaf and five sub rolls from each batch of dough.

I wonder if this simplest of doughs — just flour, water, and salt — will be the one that finally responds to tangzhong? Will the tangzhong loaf lose its crust, becoming totally soft? Will the tangzhong technique produce a loaf that remains crusty, but stays fresh-tasing longer?

Tangzhong in sourdough via @kingarthurflour

The answer is “Hate to disappoint you, tangzhong fans, but no.” The rolls are indistinguishable from one another during the 10 days it takes them to become stale.

Tangzhong in sourdough via @kingarthurflour

Ditto the loaves. Which isn’t to say they aren’t yummy. My houseful of holiday company is happy to enjoy sourdough bread sandwiches to their hearts’ delight!

So there you have it: sourdough bread doesn’t appear to derive any benefit from using tangzhong. Which speaks to its inherent “good nature” — sourdough bread’s softness (where appropriate) and shelf life are fine as is.

The rest of the story

Remember I said I’d get back to how and why you should adjust the liquid content of tangzhong dough? Here we go.

When using tangzhong, it’s important to keep dough consistency as close as possible to the original. Since the slurry absorbs some of the liquid in the recipe, it’s usually necessary to increase the liquid overall to maintain a soft dough. From past experience with converting standard and whole grain bread recipes to tangzhong, I shoot for dough with overall hydration (including the tangzhong) of about 75%.

Let’s use the Buttery Sourdough Buns as an example. Since their original hydration is 60%, during my first test I increase the amount of water in the dough to bring it up to the desired 75% — and end up with a sticky mess.

I try another batch, increasing the hydration to 67% (midway between the recipe’s original 60% and my usual 75%) — and wind up with a lovely, soft-but-not-sticky dough.

What happened? Why isn’t my usual 75% hydration working with sourdough bread?

Tangzhong in sourdough via @kingarthurflour

The answer, I suspect, is that as fed starter bubbles and grows it produces alcohol — which means the starter’s no longer exactly half liquid and half flour, but starting to edge towards more liquid. This little bit of extra unaccounted for liquid throws off my hydration calculations.

It stands to reason this will always be an issue as far as figuring hydration in sourdough bread goes. The flour/liquid balance of any starter is variable, and also subject to change; some starters are thin to begin with, others thick, and all will evolve once they’re fed.

OK, even though my tests haven’t yielded any improvement using tangzhong in sourdough, you’re probably going to want to try it yourself. So what’s the best way to figure out how much liquid to use in your tangzhong sourdough bread?

It’s simple: Ignore any hydration calculations. Make tangzhong dough starting with the amount of liquid in the original recipe. Then adjust its consistency by eye: As you mix the dough, note how dry it seems. If it’s nice and soft, there’s no need to add more water. If it seems dry, dribble in enough water to make a soft (but not sticky) dough. That’s it; no math!

One final word

So why isn’t tangzhong a good fit with sourdough?

Jeffrey Hamelman, long-time King Arthur Flour baker and author of the seminal Bread: A Baker’s Book of Techniques and Recipes, has the answer, which I’ve reworded as follows:

The acidity of sourdough bread is a natural shelf-life enhancer. “Starch retrogradation” is the tendency of the starch in baked bread to gradually release any liquid originally absorbed during the mixing and kneading process. This loss of liquid is perceived as the bread becoming stale. In sourdough bread, acidity slows this chemical process; and thus sourdough bread remains fresh (read: with a soft interior crumb) longer than standard bread.

They say you can’t make a good thing better. And in the case of tangzhong in sourdough, I guess that’s the truth.

Read more about tangzhong:
Introduction to tangzhong
How to convert a bread recipe to tangzhong
Tangzhong beyond white bread: Will it work in whole wheat and gluten-free breads?

Want to learn more about sourdough baking? Check out The Complete Guide: Baking with Sourdough. 

PJ Hamel
About

PJ Hamel grew up in New England, graduated from Brown University, and was a Maine journalist before joining King Arthur Flour in 1990. PJ bakes and writes from her home on Cape Cod, where she enjoys beach-walking, her husband, two dogs, and really good food!

comments

  1. Martin Belderson

    Fascinating piece of debunking. However, I have an oblique question about wholemeal sourdough i.e loaves with 70% or higher wholemeal flour. Over here in the UK I’ve come across some home sourdough bakers ‘boil’ ten per cent of the wholemeal flour in these loaves; make a Tangzhong in other words. I’ve tried it and the results were marginal; maybe softer, maybe not. Have you attempted this? I agree that Tangzhong is irrelevant to longevity but I can see how it might soften a dense wholemeal loaf.

    Btw, ‘sift and scald’ is a technique promoted by the Norwegian bakers Casper André Lugg & Martin Ivar Hveem Fjeld in their book ‘Sourdough’. And this technique definitely changes wholemeal loaf taste and texture. Worth a try, at least.

    Anyhow, thanks again for a great article.

    Reply
    1. PJ Hamel, post author

      Martin, we’ve found that simply using a short autolyse helps whole grains soften a bit; and since they absorb liquid during this autolyse, the dough is easier to knead. I admit I haven’t tried a whole grain sourdough recipe using tangzhong; but I’ve used it in standard whole grain recipes, and while it doesn’t seem to promote softness, it does extend shelf life. So, the takeaway? Since sourdough has such a long shelf life anyway, I suspect using tangzhong in a whole-grain sourdough loaf won’t really produce much of an effect. On the other hand, I’ll have to look into “sift and scald.” Again, since I haven’t tested it, the proof may be in the pudding (or bread, in this case). 🙂 PJH@KAF

  2. Ellen G.

    I love how well sourdough bread lasts. To get the best amount of time out of my bread i “sour” the dough in the fridge for up to three days before I bake the loaf. Then I store sourdough bread in a clean,re-used commercial bread plastic bag on the counter for a few days. Note that I NEVER touch the loaf with my hands. I use the bag as a glove for the loaf. When I forget and do touch the loaf, even with freshly washed hands, that is where the mold spots begin. I have kept my bread for a good 10 days this way.

    Reply
  3. Kitty Philips

    I don’t want soft sourdough bread. I like my bread with some chew. So, no I won’t be trying this. Thanks but no thanks.

    Reply
  4. Henya

    You are missing the point… the sourdough starter is itself a form of tangzhong… as the flour is already hydrated in the starter…

    Reply
    1. Rosalee

      Yes. You are right. I love baking breads with the tangzhong method. I haven’t made sourdoughs in a while. My family loves them more than I do. I just love baking any breads.

  5. Linda F

    I’m just getting into sourdough baking and that’s challenging enough 😉 I’m glad to know that I don’t have to try yet another variation on the theme, thanks so much for your thoroughly scientific experiment, PJ.
    Question: how do you recommend storing sourdough?
    I’m not talking about slicing and freezing, which I sometimes do. But just keeping it on the counter. I tried wrapping in a kitchen towel, and got a brick. Tried a ziplock plastic bag left open, got mould.
    I’m still beginner enough that my loaves are a little too chewy, but each time I learn something new and I’m loving the learning process. Thanks for your dedication and experimentation!

    Reply
    1. The Baker's Hotline

      You can’t go wrong with a bread box, Linda! It does a great job of letting air circulate without exposing it to too much moisture. It’s worth giving a go! Annabelle@KAF

    2. PJ Hamel, post author

      Linda, if it’s a large enough loaf you can also put it cut side down onto a clean work surface: countertop, baking sheet, etc. — then cover it with a large bowl or other similar object. You want to prevent moisture from leaving via the open interior, but you don’t want to “smother” the bread, as a plastic bag might do. Good luck — PJH@KAF

    3. Linda F

      Thanks for the suggestions, will check out the bread box too although I suspect it’s probably the size of my very small kitchen counter! 🙂

Post a comment

Your email address will not be published. Required fields are marked *