The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Food Based Lye vs. Baking Soda for making authentic German Pretzels?

guerrillafood's picture

Food Based Lye vs. Baking Soda for making authentic German Pretzels?

I am an American that lived in Germany for many years, and misses the breads of Munich so much. I have a European culinary apprenticeship under my belt and countless years of restaurant experience, but I am not able to recreate “simple” German pretzels. I find that there is a phenomenon in the American bread world. I find everyday breads in supermarkets and even artisan bakeries that look identical to European breads, but when you pick them up and take a bite, they are much softer, and well… weaker breads.

The same things happens with my pretzels. I have tried literally a dozen recipes from American baking books and even from German books written in German. And they come out looking exactly like German pretzels, but the crust is always softer than in Munich. In Munich the inside crumb is soft and supple, but the brown crust is deeply brown with a crisp crackle.

My big question is about food grade lye. Will this save my pretzels? I’ve been using a baking soda/water boiling solution before I bake the pretzels. If I switched to lye, would that make the crust better? Baking soda is an 8 on the pH scale, which is only slightly alkaline, while Lye is a 13-14 which is about like the strongest alkaline you can find. I’d hate to spend a month and $50 tracking down some food grade lye, only to find out that it is a huge hassle that produces the same or worse results than baking soda.

Can anyone help?


alconnell's picture

If you do a search for this in this forum, you'll find supporters of both camps. I, for one, use the lye and feel it makes all the difference.  The baking soda just doesn't give it the authentic taste and browning.  It is not cheap to buy because of quantities, but it lasts forever.  I use like 3-4 tbsp per liter of water, which can be used over and over.  Everyone loves my pretzels!

Now, if you could help me with my kaiser rolls.....

guerrillafood's picture

Thanks for the tip on lye. I did do a search and read through what some are saying. I guess what I really should have asked is more about where to buy lye? I went to the hardware store looking for "Red Devil Lye" as it talks about in some of my books. But now I think I heard a rumor that this lye is discontinued. And now I am reading about "food-grade lye" on this website. I certainly don't want to boil my pretzels in a toilet bowl cleaner, so now I am really confused. Also, if this stuff is so poisonous, then it seems like even 3-4 Tbsp diluted into a liter of water would still be poisonous. 

 Anyway, if you could tell me where you get your food-grade lye from (if it's the web, which website?), and if you could calm my mind about poisoning my customers, students, family, and self... I'd be forever appreciative. 

Ha! Yeah, Kaiser Rolls are my next hurdle. I saw the photos of Floyd's in the gallery section and in the recipe section of this website, and they seem to be top notch. At least they LOOK top-notch. That is always my problem with breads though. They very often look great, but don't have that crispness or that special something that European bakeries have.

alconnell's picture

Here's one place:

As I said, it is not cheap but that is a lifetime supply.  I've also heard you can buy it at craft stores with soapmaking supplies.  Now as to safety, lye is sodium hydroxide.  It is used in soap making and for drain cleaning.  It is also used in making pretzels and tortillas, or so I'm told.  I use the powdered form, which would burn you quickly if you came in contact with it.  I always wear rubber gloves.  In it's diluted form, if you dip your hands in it, they might get irritated, but again, I wear the gloves.  You also want to use glass or plastic, no metal when handling or storing it. 

I make pretzels with my 8 year old daughter all the time.  She is not allowed near the lye, which is kept way up on a shelf in the laundry room.  I do all the dipping from the sink and use plastic utensils to remove them from the bowl.  You can put them on parchment or the silicone mats and then bake them.  It is safe when properly handled.

Aah, Kaiser Rolls....The NY German Delis have such good ones.  I've tried most recipes, but haven't reached nirvana yet (no offense to Floyd - his are great!)


tananaBrian's picture

I don't think the Red Devil and other 'cleaner' or 'drain unclogging' type of lyes are being discontinued but they've become less popular as other products have become safer and more effective.  Drano and others have similar compounds in them, but exist in a less reactive form that's safer... the aluminum bits in the lye products react with the sodium hydroxide, are caustic, and produce hydrogen gas.  Some evil-minded people have been making bombs out of the stuff by putting it in those 2-Liter plastic bottles, with water in one end, the lye powder in the other, and lay them on people's lawns.  When the home owner picks up the 'trash', the water and lye mix and produce a tremendous amount of gas and the bottle explodes ...splattering the strong caustic solution all over the home owner.  I've heard that some areas are trying to outlaw the stuff because of this issue.  I doubt the food-grade lye contains the aluminum bits that are necessary for the reaction...




copyu's picture

contain aluminium pellets, to make the reaction more violent.

Plain old NaOH (caustic soda) works OK, too. but there is a MUCH bigger and better reaction with Aluminium, hence..."Drano" et al...


Mike Adams's picture
Mike Adams

Lye unarguably makes your Pretzels look, smell and taste profoundly better. Baking Soda is only a distant 2nd substitution at best. Order some "food grade" Lye on Amazon or eBay. Here's the best secret about Pretzel making I've discovered from personal experience. Mix up the Lye Solution according to instructions that came with it and keep then store inside a Spray Bottle such as the type window cleaner comes in. Here's the best part. No need to mess with boiling the Pretzels in a Lye Bath which is entirely unnecessary since they get baked anyway. Simply set the raw Pretzels in your sink then wet the tops using the Lye Solution from the Spray Bottle. Top with Pretzel Salt immediately before they have any chance to dry. This will cause the salt to embed into the dough so it can't be removed or fall off. Email:

harrygermany's picture

Hi guerrillafood,

I am German, and I try to give you some information.
Sorry for my poor English.

First a recipe for "Laugenbrezel"
The hydration is very low (only 50%), but that is OK.
You will have a rather dry and stiff dough.

500 g wheat flour
250 g water
21 g fresh yeast or a pouch (7 g) dry yeast
10 g salt
5 g sugar
coarse crystalline salt

1/16 gallon (250 ml) soda lye

About the soda lye:
It should be sodium hydroxide solution (NaOH) 3%.
Caution! That lye is dangerous. It etches most metals and your fingertips, too.
Wear disposable latex gloves when you work with it and use it in a plastic container or a plastic bowl to dip the Brezels. You can use it many times and store it in a glass bottle.
DO NOT WARM OR BOIL !!! Only use it cold.
For baking you need a thick anti-adhesive foil or a very well greased baking sheet.

In my country (Germany) you can buy it in a pharmacy.
The quality must be something like "food purity". "Technical purity" is not enough.
100 g of sodium hydroxide cost about 8 USD.

Solve the yeast in the water, add all ingredients and knead for 9 minutes.
Let the dough rest for 10 minutes.
Then form 6-12 Brezels.
Dip the Brezels in soda lye. Wear disposable latex gloves!!!
Put the Brezels on a well greased baking sheet, cut the thick parts, salt with the coarse salt and let the Brezels prove for 20 minutes.
Bake with 390°F for 22-25 minutes.


Everyone is a stranger somewhere -
so don´t give narrowmindedness or
intolerance no chance nowhere.

guerrillafood's picture

Vielen Dank für deine Hilfe. Dein English ist schon sehr gut. Wahrscheinlich viel besser als mein Deutsch. Aber ich übe sehr gern. Also, jetzt schreibe ich auf Englisch, denn es gibt hier so Viele die kein Deutsch können. Ich will nicht unhöflich sein.

Thanks for your recipe. Now if you just had a good recipe for Schwarzbrot like I always had when I lived in Munich. 

I'm glad you told me about the food-grade lye, and that I shouldn't boil it. Now my only problem is where to buy it. On the internet I have found Lye online at the International Scientific Supply Services:

But it costs $40 and comes in 3 lb. batches. I need maybe 3-4 Tbsp at the most. Then I found Lye at the Green Bulldog:

They sell if for "home bio-diesel production". It is MUCH cheaper $18.99 (this includes shipping!!!) for 1 lb. But as you pointed out, I can't rest assured that it is food-safe.

So, although I'd love to try out the lye, I can't see myself paying $40 + shipping charges for a trial. So if anyone knows of a cheaper place to buy food-quality lye, please let me know.


Noch mal, vielen Dank.


alconnell's picture


I will mail you some if you like.  Send me an email (remove the dashes)

Another recipe for German Pretzels:



guerrillafood's picture

I sent you an email about the Lye. Let me know if you didn't get it. But the recipe for Laugebrezela II looks fantastic. The "green dough" aspect of it is something I never expected but makes perfect sense now that I see it. And making a large pizza shape and cutting the dough into triangles to be rolled up into ropes to be shaped into pretzels... absolute genius idea for not over developing the gluten by pulling, stretching, and rolling little balls into ropes. And slashing the "belly" of the pretzels is something I've never done, but now that I see it, every pretzel in Munich had that tell tale bursting slash mark. Now I can't wait to find some lye.

I went to the chemical website suggested earlier in this post and found the lye that he ordered in 1999 for $38. It is $75 now for the same 500g. Things seem to be getting worse. Well, I live in Athens, GA which is a really big college town with UGA two miles from my house. I think I'm going to email the Family and Consumer Science Dept, and see if they don't maybe have some Sodium Hydroxide in bulk. If not, I guess I'll just have to save up a month and make the plunge for the $75 bottle. Scheiße!!!

Thanks for your help!

alconnell's picture

Here's another site which wasn't around when I bought mine for $40!

 Not sure what micro beads are, but it is food grade and probably comes with MSDS sheets and warnings.


Antilope's picture

Here are working links for the above German Pretzel Recipe posted by alconnell, on The Wayback Machine (www. cs. uml. edu /~dm / brezla /):

Laugabrezla I

Laugabrezla II


JERSK's picture

   I was at the King Arthur Flour store in Vermont and they had food based lye on the shelves. I just remember it because I'd never seen it before and wondered what it would be used for. It seems like it wasn't a very big container. I don't know if it's safer than the stuff they use in Drano. I'm sure you can contact them and they can tell you what you need to know.

halfrice's picture

you can buy lye water from chinese supermarket.

highmtnpam's picture

We lived for some years in Memmingen, east of Munich.   Do you have a recipe for what was called 'Brown Bread'?  I have tried several and have not found one close enough to what I remember.  T

Thank you so much, Pam


copyu's picture

that we just can't seem to drop from our's not quite "meaningless", yet, but an extremely confusing term

Think of it as just an abbreviation of 'al-ka-LI'. Every liquid you test will be either alkaline, acidic or neutral. That means: if it has a pH lower than 7.0 (which is the pH of pure water), it's "acidic"; if it has a pH of over 7.0  then it's "alkaline". However, that alone does NOT mean it will make good pretzels. (eg: sea-water is 'alkaline' doesn't react well with pretzel dough, however...)

German pretzels are made with food-grade NaOH, sodium hydroxide, a very strong and dangerous alkali (caustic soda). A strong solution goes up around pH14 (the MAX!) Soap-makers use it, as well as KOH (which is potassium hydroxide) and the latter seems to be the more common for soap-makers, these days. I don't know why, exactly—perhaps it's the cost? I've never seen KOH recommended for pretzel-making, or any other baking, so personally, I'd forget about that one

Our ancestors made their own wood-ash 'lye', which is usually a tad stronger (higher pH) than baking soda, but nowhere near NaOH in strength. Similarly, Chinese 'lye water' is also 'wood-ash' (soda-ash) or commonly, a mixture of sodium carbonate and potassium carbonate. OK for noodle-making and a little bit stronger than baking soda. I doubt it would be as effective as NaOH for pretzels. If you use a weaker alkali, you may need to soak (or simmer) your pretzels in your alkaline solution for a longer time, which may not make the best pretzels. I've never tried it

On US websites, I've seen food-grade NaOH for $4.99 per 2lb. In Europe, it's much more expensive, but they only ship to a few locations—Germany, Austria and either Switzerland or Holland...I forget which. My relative in Germany ordered some and shipped it to me among some other baking-related supplies



KYHeirloomer's picture

Just worked through this thread, and I'm really confused.

Can't speak for Europe, but food-grade lye is readily available everywhere in the U.S. Just go down to the nearest hardware store. I get mine at the local ACE, for instance. Cost's less than four bucks for a pound---which lasts two days longer than forever.

I think we sometimes get carried away in our search for ingredients.

BTW, I've made Bavarian style pretzels using both lye and baking soda. I'll take the lye, any day, for that hard, shiny crust. Baking soda, on the other hand, is great for bagels.

Bread Buddy's picture
Bread Buddy

Please explain how to use the lye when making pretzels.  When I have used baking soda, the formula read to boil the pretzels in the baing soda/water solution for 30 seconds.  Here I have read not to heat the lye in water, or use a metal container.  What is the process?  If the pretzels are just dipped into the water solution are they to be boiled afterwards, then baked?  I understand the lye solution provides the shinny hard crust, but I think the boiling provides the chewy inside.

Does anyone have a formula for the soft pretzels using lye with the full details on the method and the proportions of lye to water?


copyu's picture

Add lye pellets or powder to water, slowly; NEVER add water to lye

Use 3% to 4% [MAX] solution

Make sure lye is FULLY dissolved before dipping pretzels. It can take time

ALWAYS use glass (or plastic) containers for dipping

Wear rubber gloves and splash goggles for safety

Keep well away from children and VERY far from anything ALUMINIUM. Best to avoid ALL metals

Dipping is fine, if you can manage it safely, or use a NEW pastry brush to paint the lye on the pretzels. Leave them for a while on parchment or a wooden board (follow your formula) before adding salt or seeds and slashing

Store lye solution in a plastic bottle with a tight-fitting lid and clearly labelled, preferably with a scary warning (or tip it down the drain in the bathroom's drain cleaner!)

Check txfarmer's blog for good dipping, shaping info

Hope this helps!


crazyknitter's picture

My first experience with pretzels were in Germany.  My father was in the Army and we were stationed in Germany.  I fell in love with them!

So, my first and only attempt at making pretzels was dissatisfying.  And I believe it had to do with the lack of lye.
Now I have got to try it again with the lye.



KYHeirloomer's picture

One comment on copyu's post: Lye will stain wood a lovely black. So, if you use wood as a work surface, don't use your good cutting boards or wooden peels.

Bread Buddy: After shaping the pretzels let them sit in the fridge overnight, so the surfaces become dry and crust-like. Then---following copyu's mixing and safety instructions---prepare the lye solution. If you're using lye crystals, dissolve 1 tablespoon in 1 cup of water to achieve the proper solution. I've not used anything else, so can't help with proportions when the lye is in other forms.

Wearing rubber gloves, dip each pretzel in the lye solution for about 15 seconds and transfer to a parchment-paper lined sheet pan. Top with seeds, salt, or whatever, and bake as usual.  

You can find the entire procedure (along with a pretty good formula) in the Culinary Institute of America's Artisan Baking At Home, published earlier this year.

One other word of caution: When working with lye, allow no distractions. Turn off the phone, kick the dog outside, send the kids to grandma's for the duration. Used with proper precautions lye is perfectly safe. But it can be incredibly dangerous if you let it be.

copyu's picture

I spent a good part of 10 years in my younger days, stripping paint and varnish, by hand, from the so-called "red pine" [some dark-colored Baltic softwood] in my first house in Australia, built about 100 years ago...13 paneled doors (=26 architraves!) skirting-boards 12 inches tall in seven rooms, coved architraves with little pyramids in each corner...beautiful woodwork, but a PITA to strip the paints and stains!

Caustic soda would make the beautiful, dark wood turn a nasty, dark-gray and also affected the (animal-glue) joints...a friend of mine, who was a chemist, sent his doors and skirting-boards out to be dipped in caustic soda and then spent many months bleaching, then re-staining them to the original color...

I'm probably the only person of my generation (in that city) to do the job completely by hand! (Hooray for me? Maybe I'm stupid!) Most of my other friends just gave up, removed everything and replaced the woodwork with modern reproductions...they had more money than I did, though...

Thank you for the reminiscence (and the great advice!),



Bread Buddy's picture
Bread Buddy

Thank you for explaining the dipping process and other helpful hints.  I have been wanting to try using lye for pretzels and bagels but have been very apprehensive.  With your suggestions and cautionary statements, I think I have the information I need now to give it a try.

asicign's picture

If a heavy metal is a contaminant in a product, it's not going to show up on the ingredient list.  However, the 'food grade' version of a product has been tested to ensure that contaminants are below the allowable limit.  The technical version of the same product is not tested for contaminants, so it's a safer alternative to go with food grade even if it's more expensive.

polo's picture

I started out boiling my bagels in a lye solution (one tbsp/quart) and was using drain cleaner (labeled 100% NaOH). It was just fine. I suffered no ill effects and I believe the stuff is just fine to use. That being said, I now use the food grade variety.

I found that people seem to be put off by the fact that you use lye in the process to begin with, I figured they would really croak if I asked them "please hand me the drain cleaner, yeah that's the stuff, the bottle with the big skull and crossbones on it".

The lye I got was the stuff they sell on Amazon. Two pounds for a little less than $5, shipping is almost $12 (not $25!). It is labeled as high quality, food grade NaOH and it is Kosher certified. I'm glad I got it, but if I were the only one eating the bagels, I would of stuck with the drain cleaner.

copyu's picture

...but we 'humans' have this innate, hard-wired fear of "CONTAMINATION", especially when it comes to food and drink

If our ancestors hadn't had that fear, we obviously wouldn't be here, talking about it now, on the internet! However, humans, as a group, despite our lengthy education, don't have much better understanding of Math than birds or dolphins do...

If you told me there was 0.000006 grams of a very toxic, cumulative pesticide in my salad, that kills 30 out of every thousand people who eat it, my 'gut' feeling would say, "Eat something else!"

It would probably take my brain a couple of weeks to work out that my 'second choice' (grilled fish, or a steak with veges, say...) was probably twenty times more 'toxic'...but that's Math and that's 'human nature'. Math and human nature are not really very compatible in my humble opinion...





Davefs's picture

Speaking of toxicity,On the TV program "My strange addiction"recently they had a woman who had been eating Comet Cleaser daily for YEARS.Her main problem was ruined teeth.

Amazing what the human body can take!

Kind of makes the horror some see in using lye seem a bit overblown.

Of course I'm careful and did spring for the food grade stuff.

tananaBrian's picture

It said $12 when I tried getting some from Amazon too, but then during the check-out process it said they couldn't ship it to Alaska.  Through a different seller that I found that WOULD ship to Alaska, they said they had to smack the hazmat fee on it.  Maybe its because even so-called "ground" shipping to Alaska tends to go by air, that we have to pay a fee that people in the Lower 48 don't ...assuming they use ground shipping only.  Dunno...  I ended up buying a couple of pounds from a local scientific chemical supply house in Anchorage and paid a dear price, but a price that was a couple bucks cheaper than having it shipped up here on my own.



polo's picture

that there must have to be some compensatory inconvenience involved to live in such a beautiful state. I didn't realize that you lived in AK.

MiserDD's picture

Lye sale until Friday July 1st.  About half of normal price.

Bohemian Mama's picture
Bohemian Mama

I found liquid food grade lye in a chinese grocery store in cairns Australia,, perhaps other Aisan food stores may stock the same product.


copyu's picture

Our ancestors made their own wood-ash 'lye', which is usually a tad stronger (higher pH) than baking soda, but nowhere near NaOH in strength. Similarly, Chinese 'lye water' is also 'wood-ash' (soda-ash) or commonly, a mixture of sodium carbonate and potassium carbonate. OK for noodle-making and a little bit stronger than baking soda. I doubt it would be as effective as NaOH for pretzels. If you use a weaker alkali, you may need to soak (or simmer) your pretzels in your alkaline solution for a longer time, which may not make the best pretzels. I've never tried it

tananaBrian's picture

Splattering hot caustic solution?  Even if not very strong, I don't think I'd want that in my eyes... :(




polo's picture
polo splattering plain boiling water into your eyes? I wouldn't want either to tell you the truth.


copyu's picture

The "online calculator" you used is quite incorrect, I'm sorry to say. The pH value it gave you is ridiculous for "Red (/Red Hot) Devil" Lye. This product has a value closer to pH14 than pH11-12, which represents an alkali from several hundreds to a thousand times stronger. You quite correctly stated that the pH of ammonia is around the figure of pH11 or so.  The "Lye Water" sold in Chinese grocery stores for making noodles is about the same value and so are 'baked baking soda', 'washing soda', 'sugar soap' and other cleaning compounds and home-made ("wood-ash") alkalis.

Drain cleaners, paint-strippers and the traditional 'soap-and-pretzel-making' alkalis are much more powerful, by several orders of magnitude. (That's probably why the counter-top was marked.) Please use "RD" or "RHD" carefully!

If you have any pH measurement equipment and find the solution of "RD" measures lower than pH13, it may be that you have been impatient—the stuff I use is a little bit more 'coarse' than supermarket white sugar, but it takes quite a bit of time to fully dissolve, even  in distilled or purified water. The "bead" type takes much longer and, if you use regular tap-water, it may take longer still...

Best wishes,


PS: check out txfarmer's pretzel blog on TFL for more info...


catlick's picture

I make Nancy Silverman's pretzel recipe from "Breads from the La Brea Bakery" and I think they come out perfect!  Crisp thin crust, and I always use the lye solution.   They are the ones on the right.  The ones on the left are Redheads recipe.  Little softer texture, but good.

gary.turner's picture

NaOH is very hygroscopic and very reactive. It is almost impossible to package it in pure form. Except for the elemental Fe, all those are normal results of reacting with water and its trace elements.



dosco's picture

So what did you end up trying? Did it work?


Just to recap, you can get good potassium or sodium hydroxide from Essential Depot, and yes, the shipping is expensive.


Washing soda can be purchased at your local grocery store ... it is made by Arm and Hammer and can be found in the aisle with the laundry soap. I use it extensively as an additive for washing clothes.


Finally, if you're looking to try drain cleaner, Roebic brand is sold at Lowe's and, is far as I can tell, relatively pure hydroxide (especially when compared to Red Devil).


If you haven't yet tried a "pure" hydroxide, I echo the safety comments made by others in this thread. Keep some water and vinegar handy when handling it, and wear rubber gloves and eye protection. I made a batch of soap and tried the "zap test" (put a drop on your tongue) ... I got a very very nice chemical burn on my tongue. It hurt, it looked horrific, and took about a week to heal. Not fun and I shudder to think what would happen if that stuff got in someone's eyes.




goer's picture

Never heard of it. I thought lye was lye. :)


Steel_Wind's picture

I loved this discussion. Read all of it. I am in the lye camp and have put out feelers through a professional baker client of mine to find a source of micropearled lye in the Toronto area in smaller, non-commercial quantities (Bringing 25 kg of sodium hydroxide into my home is basically HazMat in that quantity and a non-starter. FWIW, Sodium hydroxide is stored within desiccation vessels in a lab environment. My wife, scientist that she is, would go nuts if I have it around in quantities larger than a vitamin jar. And even then...)

One thing that was only obliquely referred to was the proffered observation that before the NYC Bagel became known for blanching the bagel in malted water before baking, the European version of the bagel may well have evolved from being dipped in lye as well. The products are very similar, after all.

We can fight about the desirability of whether a bagel should be dipped in cold or boiling 3% lye instead of malted water another day. But what has me interested is whether anybody has tried to bake their pretzels, pretzel salt, poppy seed or sesame seed side down for the first 3 minutes on well soaked burlap covered bagel boards, and then flipped the pretzels over on to their bottoms on stone to finish off. I think that might lead to a very pleasing texture and finish. 

And yes, that would be the exact approach used when baking NYC bagels. This makes sense to me and, better still, gives me yet another reason to put together some bagel boards (as I have planned to do anyways)

Anybody tried this approach when making pretzels or heard of it being done that way? 

MiserDD's picture

Lye - 2lbs 10.99 USD -

Pretzel salt - 10lbs 9.99USD - (Pretzel M salt)

Not sure what the use of a soaked burlap bag with the flip would be, but using a pizza screen does a nice job.

Steel_Wind's picture

Thanks for the reply and the links; however, when it comes to lye, shipping cross the border at a consumer level is not possible. Americans cannot order lye from Canada and vice-versa.

I did find 10kg (22 lbs!) of pretzel salt locally for $12.00. What I would do with 22 lbs of pretzel salt, however, is another matter.

Burlap covered bagel boards is an old trick which originated in NYC at the turn of the 20th century. A bagel board, typically a 1"x2" or a 2"x4" board is covered on the top side in burlap and this whole board is soaked in water for a good hour before backing. The burlap soaks up much more water than the wood and the bagel is placed "topping side down" on to the burlap side of the board. Burlap is cheaper than wood. The board is inserted into a 500-500 degree oven. Now, as soon as that wood gets to temperature, it's going to burn. Wood burns at about 450. The soaked burlap gives the wood a little longer in the over and protects it from the heat so that the wood does not have to be thrown out. The burlap also provides a "steam boost" directly to the surface of the top of the bagel and makes the texture more firm and chewier.

By placing the bottom of the bagel exposed to the hot air inside the oven for the first 3-5 minutes, the bottom dries out quickly so that it is less likely to stick to the stone when it is flipped, but the bottom is not on the stone for so long that it burns. If the bagel was put onto the stone on its bottom from the very start, the bagel would stick to the stone and the bottom would burn. Neither is what you want.

The bagel boards are carefully tipped/flipped about 3-5 minutes into the baking process so that the bagel falls off the board and now rests on the stone where it finishes baking for the next 12-15 minutes.

Why does all this have to do with a Pretzel? Simply that the basic approach to making bagels and pretzels are very similar to one another and the traditional bagel board used for baking a NYC bagel seems a natural fit with pretzels.