Why and How to Boil Bagels – Science of Bagels

You boil pasta, noodles, and gnocchi. You bake cake, cookies, and bread. Bagels, on the other hand? You bake AND boil them. As a matter of fact, doing both is crucial for getting that chewy, characteristic bagel texture.

And there’s more. How you boil your bagel can also drastically impact its color and gloss. And, it influences the final flavor of your bagel. About time we have a closer look at the importance and use of bagel boiling.

The basics of bagels

Before we dive head-on first into the boiling water, let’s zoom out and have a quick refresher on bagels in general.

Bagels are circular breads, with a hole in the middle. They might have the same shape as donuts, but taste very different. They tend to be savory and are a lot chewier and sturdier than a donut tends to be.

Bagels start out as quite a regular bread dough. You mix water, wheat flour, yeast, salt and maybe some sugar, into a firm sturdy dough. The dough doesn’t tend to be as flexible as you’d use for a ‘regular’ loaf of bread.

At some point during the process, the dough is left to proof. You might do this before the dough is shaped into rings. Others proof the dough in bulk, before shaping. During this time the yeast converts sugars in the dough into gas bubbles – carbon dioxide. This is what helps create a light and fluffy dough.

The bagels are boiled after both shaping and proofing. After this quick dip in hot water, they are finished by baking them in the oven.

The end product is chewy, relatively dense bread. Bagels don’t have a true crust, but a good bit.

A note on NYC vs Montreal bagels

If you decide to dig into bagels, you might find yourself caught in a heavily debated argument. Which bagel is better? The Montreal or New York City-style bagel? Both cities have a strong bagel history and a crowd of committed fans. Which is better mostly depends on who you ask.

Generally speaking, a Montreal-style bagel is smaller, but has a bigger hole, than its NYC counterpart. The Canadian bagel makers tend to sweeten their boiling water with a little honey. This is not regularly done in New York. Lastly, a classic Montreal bagel is baked in a wood-fired oven. Again, not something the New Yorkers do.

Why do you boil bagels?

Boiling a bagel is what gives it its characteristic texture. Skipping the boiling step makes a ‘regular’ bread, that just happens to be shaped like a bagel. Boiling gives it the chew. And it ensures there’s no crispy crust.

What happens during boiling?

As soon as the bagel hits the boiling water, it starts to change. Several major changes happen that are crucial for becoming a bagel:

1. Gelatinizating starch
2. Inactivating (some of) the yeast
3. Alkalization of the outer layer (optional)

Starches gelatinize – defining the structure

First of all, the starches in the flour of the dough gelatinize. Starch granules in the flour absorb water. As a result, they swell, until they break. At that point, starch molecules are set free and absorb even more water and ‘cook’ the bagel.

Gelatinization of starch is a very common process in carbohydrate-rich foods. Boiling potatoes, making a roux for a pie filling, they all rely on the gelatinization of starch to get their distinct texture.

Once the starch has gelatinized, the dough loses some of its flexibility, but also vulnerability. The outside has become sturdier and can de handled more easily. It does mean that the bagel can’t expand that much anymore from now on.

Another effect of the starch gelatinization is that a lot of the water on the outside of the bagel has now been bound. It is no longer free. As a result, it won’t evaporate as easily anymore in the oven. This again ensures that the bagel doesn’t get a crunchy crust, like some other breads do.

Lastly, this process is crucial for creating a bagel with a nice shine and gloss!

Yeast deactivates – but not all

Baker’s yeast thrives at body temperature. However, once it gets too hot, yeast is inactivated. Remember that yeast is a living microorganism. At high temperatures the internal systems stop working. Boiling water is definitely hot enough to instantly kill off the yeast.

That said, it does take some time for that heat to fully penetrate the whole bagel. As such, some of the yeast in the center may survive.

Alkalization of the outside (optional)

Lastly, if you boil the bagels in alkaline water – such as water with dissolved baking soda – you can alkalize the outside of the bagel. That is, you increase the pH-value on the outside.

This does not lead to a visible difference at first. However, once the bagel has been baked, those boiled in alkaline water are significantly darker in color! The change in pH-value has sped up the Maillard reaction, causing the bagel to brown faster.

Does steaming vs. boiling make a difference?

Boiling bagels gives them a characteristic texture, nevertheless a lot of larger manufacturers have moved away from boiling. Instead, they use steam to pre-seal the bagels. It is simply easier to steam large quantities of bagels than it is to boil them.

However, it does result in slightly different bagels – and opens up some new opportunities:

• More delicate doughs: to boil a bagel, the dough needs to be sturdy enough to survive a drop and dip in water. In steam ovens on the other hand, the bagels undergo less handling. As such, more delicate, lighter doughs can be used!
• The bottom doesn’t shine because the bottom of the bagels in a steam oven often don’t pre-cook as well!

What do you boil bagels in?

Aside from of course water, the boiling liquid for bagels can contain a few other ingredients. These ingredients can change the flavor and appearance of the bagel. Use it to your liking!

Sugars – add flavor?

The boiling liquid for bagels often contains honey, malt syrup or (brown) sugar. They can make the bagel a little sweeter, or add a little flavor.

However, we found that both brown sugar and honey didn’t add much to our bagel in terms of flavor. A slight sweetness, maybe, but not much.

Boiling bagels is useful for another reason than just texture: taste. As the Montreal bagel bakers showed, you can add honey to the boiling liquid. This gives the bagel a slight hint of sweetness and improves browning in the oven. Another option is to add other sugars such as malt syrup.

Baking soda – makes a brown bagel

What did make a big difference? Using baking soda in the boiling water! As we discussed above, increasing the pH-value of the liquid impacts the outer layer of the bagel. As a result, the final bagel turns a nice dark brown color in the oven!

If you use too much baking soda, your bagel may even start to taste like a pretzel! Pretzel also get an alkaline treatment to develop their color and taste. We caught this flavor when using 1 tbsp baking soda / liter of water.

How long to boil that bagel for?

So, you’re all set to boil some bagels? But, how long should you boil them for?

Unfortunately, there is no one ideal boiling time. It depends.

• On the size of your bagel – thicker bagels can handle more boiling.
• On the texture you’re after
• On the extra puff from the yeast you’re after in the oven

Texture – firmness and strength

The shorter you boil your bagel, the thinner the layer of cooked dough on the outside. You could technically cook the whole bagel for several minutes. By that time, all the starch will have gelatinized. As a result, the shape will be set. It can no longer expand in the oven. Also, it will become quite tough, maybe a bit too tough for most bagel lovers.

It’s why most bagel recipes instruct you to boil them for a limited amount of time, often just 30 seconds per side. This ensures the outside is cooked and firm. However, the inside will still be pretty much raw. As such, the inside is still flexible. In the oven, these doughs can still expand a little, making for a nicer, rounder bagel!

Want to keep yeast alive?

In the oven, bagels can still puff up a little. This is due to water in the bagel that evaporates, but can also be due to some residual yeast. Upon entering the nice warm oven, the yeast gets a last push to grow and produce gas.

This is highly desirable. Bagels that have only been boiled often look less than perfect. However, in the oven, the last expansion of the bagel makes them round and puffy!

Bagel Troubleshooting

Ready to make some bagels, but still have some questions? Hopefully, we’ve got them covered for you!

References

The Engineering Toolbox, Properties of Saturated Steam – Pressure in Bar, link ; data used for explaining difference in boiling water vs steam heating

Fairmount Bagel, 2019, How to make the perfect Montreal bagel: 100 years of wisdom from Fairmount Bagel, Youtube, link

The Fresh Loaf, Montreal Style Bagels, 2009, link ; this makes a firmer, less proofed bagel

Maria Godoy, Chew On This: The Science Of Great NYC Bagels (It’s Not The Water), May-21, 2015, NPR, link

Parks, S., Homemade Bagels Recipe, Jan-30, 2017, Serious Eats, link

Reinhart, P. New York Style Bagels, Fine Cooking issue 43, link

Reinhart, P., The Bread Baker’s Apprentice: Mastering the Art of Extraordinary Bread [A Baking Book], 2011, p. 115, link

Seattle Bagel, About us, link

Spot Bagel, Boiled Bagels vs. Steamed – How to SPOT the Difference, 2011, link

Togut, L., New York’s Best Bagel Comes From a Department Store, Sep-5, 2014, Serious Eats, link