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Sourdough Bread


Sourdough Pretzels

I love soft pretzels. My mother is Pennsylvania "Dutch", and I remember her making pretzels as a child. I loved the unique taste of the crust, and thought it was so cool that you could cook something out of what is essentially drain cleaner, and it wouldn't hurt you.  Heck, I think still think it's cool.

So I figured I'd try to make some using sourdough. It took a few tries to get it right, but it isn't difficult. There are other sourdough pretzel recipes online. However, most do not use lye.  King Arthur's recipe calls for yeast in addition to sourdough starter.  This recipe seemed closest to what Mom made, so I adapted it. It also has a lot of interesting reading on lye.

Another thing unique about this recipe is that it uses the same old high-gluten bread starter that I use for my normal bread baking. High-gluten dough is not good for pizza crust or pretzels or anything that needs to be formed.  It is too stretchy.  My first try was using all-purpose flour with the high-gluten bread starter.  It was passable, but still hard to form and didn't have the taste and texture that other soft pretzels I have had. It was too much like bread.  All-purpose flour works great. I also tried cake flour.  It was easier to form, but I prefer the taste and texture of pretzels made with all-purpose flour.


A lye (sodium hydroxide) bath is what gives pretzels their unique flavor, hard crust, and rich brown coloring.  It breaks down the protein on the surface of the pretzel into a slimy goo.  This slimy goo hardens during baking, making the crust.

Red Devil lye used to be a common grocery store item.  Red Devil quit making it, and lye it is now more difficult to obtain.  Fortunately it is used by soapmaking hobbyists, and is  available, albeit in rather large quantities.  Lowes building supply carries Roebic Labratories 32-oz Drain Cleaner Crystals. Make sure it says "100% Lye" on the label. It costs about $15.00.  This recipe uses about an 2/3 oz. of lye. Amazon.com has it also.  Someone is selling 4 oz for $6 delivered.  The best bang for the buck on Amazon is 2 lbs for $12 delivered. Perhaps you can split it with a friend or two. Just keep it tightly sealed so it stays dry (lye attracts water from the air), and it will last forever.  I am using up some Red Devil I have had lying around for years. 

Food-grade lye is available.  From my reading, chemicals is chemicals.  Any product that is "100% Lye" will work.  However, there are posts on the internet (so it must be true, right?) that express some concern that non-food-grade lye may contain trace amounts of mercury or other heavy metals. Our birth control used contained mercury, so I figure a little more won't matter.  But seeing that food grade costs no more, you may as well play it safe.

Most pretzel recipes use baking soda instead of lye.  I have never tried it, but do not see how it could possibly work. From my reading, everyone who makes lye pretzels agree that there is no substitute for lye. 

 I have also seen recipes that for safety reasones, use sodium carbonate. (Not to be confused with sodium bicarbonate, which is just baking soda.) Sodium carbonate is what lye breaks down into when heated and is not toxic.  Again, the consensus is that sodium carbonate is not as good as lye. It may taste more like an authentic pretzel, but will not affect the crust like lye will.  Lye is easier to find than soduim carbonate, and can be used safely.  It used to be a common kitchen item. Heck, people use it in their hair as a relaxer.

Lye Safety

I am not going to cover using lye safely here. If you have not handled lye before and are not comfortable doing so, read the precautions on the container, and search the web for "lye safety". Wikipedia has a good article on lye.   If you are the overly cautious type, you probably wouldn't be reading this anway.  All that gluten....

The good news is that lye can be used safely if you use common sense.  Furthermore, the solution used for pretzels is quite diluted and a lot safer than using it to make soap or clean out your drain.  Play it safe. Wear glasses and rubber gloves. Lye is corrosive. Use only plastic or glass containers and implements, and rinse thoroughly with water when done.  I don't recommend doing this, but I have dipped my hand in it with no ill effects.  If you do get some on you, rince proptly.

To dispose of the bath when you are done, simply dump it down the drain and  turn on the faucet. You can also save it in an airtight, clearly-labeled container for future use.

I'll repeat:  The lye is broken down into  sodium carbonate during baking. Sodium carbonate is harmless.  The pretzels you will be eating contain no lye.

So, lets get started!

Equipment you will need:

  • a cookie sheet lined with a silicone baking mat or parchment paper.  I found sheets of silicon rubber that fit perfectly on my oven rack on Amazon. I remove my oven rack, cover with the sheet, and return the rack and sheet with my pretzels on it when time to bake. 

    You may also use silicon bread and cake pans.  I tried well-greased glass. The pretzels stuck like glue. The mess could not be removed without soaking.  The lye gelatinizes the outer layer of the flour, and apparently makes a great adhesive when heated.
  • A glass or plastic bowl for dipping the pretzels in the lye bath. Choose a bowl that is just big enough to hold a pretzel with the sides being vertical and deep enough so that the solution won't slosh out. See the photo below.  The goal here is to make the two cups of water deep enough to cover a pretzel.  If you don't have a suitable bowl, simply double the tap water and lye and use a larger bowl. Add the lye to the water.  Do not add water to dry lye.
  • A spray bottle of tap water. I got mine at WalMart in the home area, intended for ironong. It set me back 88 cents.

  These are the ingredients  you will need: this recipe will make four or five large pretzels:

High-gluten bread flour starter
All-purpose or cake flour
Water, preferably chlorine and flouride free. See the article on bread baking
Coarse salt for topping the pretzels (optional).

Use our bread calculator to determine the quantities needed.  Allow 125 grams total dough weight for each pretzel desired. If using bread flour starter, shoot for around 20% starter. It is hard to form the pretzels if your flour has too much protein, so keep the amount of bread flour used to a minimum.  Start with 55% hydration and add a little water if needed.  A wetter dough is easier to form, but you do need to be able to handle it.

Morton Coarse Medeterranean Sea Salt is perfect.  It is avaliable from WalMart for about $2 for a half-kg. I repackage in an airtight container. Morton also makes Coarse Kosher salt, which you will also see on the grocery shelves. I called Morton and asked which would be best for pretzels. They said that the Coarse Sea Salt is what I need.  Coarse Kosher Salt is flakes instead of granules. You could always use table salt.  Or pink Himilayan salt.

I tried the salt that comes with Super Pretzel soft pretzels that you buy in the frozen food section.  It does not work well.  The granules are apparently composed of powdered salt.  It pretty much dissolves when you put it on a wet pretzel.

Here is te recipe for the lye bath you will wash the pretzels in:  This amount can be used for almost any quantity of pretzels.  

1 tablespoon lye crystals.  Or weigh out about 20 grams. This is 5% by weight. If using pellets or flakes, you should weigh to get the proper amount.
2 cups of tap water.  It does not need to be chlorine free.

Mix the lye solution. Put the two cups of tap water in a glass or plastic bowl , then add the  the lye.   Do not dump water onto dry lye.

Mix and knead the starter, flour, water, and salt.  Keep kneading to a minimum.  We aren't making bread. Pretzels should be denser than bread.  I mix with my KitchenAid mixer on low speed for about two minutes until the ingredients are combined into a shaggy ball, let sit for 15 minutes, then mix on low speed for five minutes. Adjust the hydration as necessary to get dough that just barely sticks to your hands. You need to be able to hande it. The all-purpose or cake flour will knead faster than bread flour. It should form a window pane, but the window pane will not be as thin and stretchy as described in our bread recipe.

Cover your mixing bowl and allow to rise to double the volume or a little more. The poke test should work.

Form into pretzels. If you have a scale, 125 grams of dough is the proper amount. A hint for weighing:  Place the whole bowl of dough on your scale.  Hit the Tare button to zero the scale. Remove dough until the scale displays -125. Press Tare again to zero, and repeat.

Let the 125-gram ball of dough rest for a minute, then gently form into ropes about 24" long. I roll between my hands to get started and then roll and stretch on the countertop.   Mimimize handling as you do not want to squeeze out all of the gas formed during proving.

Form the pretzel. Here is a good video to assist you. A hint -- make the loop plenty big. 

Place the pretzel in your lye solution for one minute.  Remove and place on your pan or baking sheet. I find a slotted spatula works best for removing them.  Be sure to rinse the spatula when you are done using it. You may get your next ball of dough out of the mixing bowl while the pretzel is soaking.

Place a pan of water in the oven, on the bottom rack.  Preheat to 400 F (205 C). If your oven has a vent (usually under the back - righthand corner burner), cover it with a tin-can lid.

Salt the pretzels if desired.

Mist the heated oven with several sprays from your spray bottle, then put your pretzels in the oven on the top shelf. The moisture keeps the crust soft longer and allows for more oven spring (rising while baking).

Put the pretzels in the oven on the top shelf. Bake for 12 -15 minutes.

Determining the optimum bake time is tricky. I have been unsuccessful using a thermometer to check the internal temperature. The thermometer read 200 degrees F (93 C), but the pretzels were a little underbaked.  I think the thermometer doesn't work well because you can't insert it deeply into the bread like you can for a loaf.   They will turn a nice pretzel-brown color and smell like pretzels.  Err on the side of underbaking. 

 I like to underbake just a bit (par bake), then bake them a bit longer in a 400-degree F (205 C) toaster oven before eating. Get them good and hot.  Don't merely reheat.  If the pretzels have been sitting out for a couple days, this softens the inside and makes the crust crispier.  The crust seems to keep the moisture from evaporating. 

You can wrap them in plastic wrap while fresh, and freeze.

Pretzels after they have rizen and been immersed in the lye bath


Copyright 2018-2019 by Dennis Hevener.

Updated Feb/21/18.

Updated Dec/25/19.

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