# Can I use lye as a cooking leavener instead of baking soda?

I'm interested to try to make waffles using a concentrated food-grade lye water mixture instead of baking soda as a leavening agent. I have three questions related to this subject:

1. Would this potentially make my waffles fluffier (due to increased CO2 producing reactions or otherwise)?
2. Would it impact the flavor of the waffles?
3. Is it safe to ingest waffles that have had a lye water reaction occur in them? (Obviously I should let the lye reaction complete before ingesting).
1. How long should I let a lye reaction occur before cooking?

Notably, I often use sourdough starter in my waffles, which has an acid component - I've noticed that I get a strong reaction from the baking soda as a result, and it got me thinking that I would get an even stronger result from lye, but I'm worried about taste and ingestion safety.

• Typical “food-grade lye” is just an aqueous solution of sodium hydroxide $(\ce{NaOH})$. How do you expect to generate the carbon dioxide $(\ce{CO2})$ that acts as a leavening agent? – Loong Jan 18 '16 at 18:27

I'm not an expert here, but, as a chemist with a strong gastronomic interest (and a penchant for waffles), can suggest some things which may be helpful. Lye is a caustic alkaline solution, traditionally KOH, and more commonly these days NaOH.

First, my understanding of lye as an agent in cooking is limited to its use in pretzels and "laugen" bread and ramen soups. The pretzel making process involves a final dipping of the dough in a lye solution in order to promote the Maillard reaction during cooking; this is not the same as the leavening process. Ramen noodles are a type of "alkaline noodle" and I believe use the lye to break down the gluten to make the flour more pliable and less elastic. Again, not the same as the leavening process.

The use of lye as a leavening agent comes from taking lye (produced by washing fireplace ash) and boiling with lard to produce potash. The purified version, pearl ash, was one of the first chemical leaveners used in the kitchen. Pearl ash acts as a leavening agent by reacting with an acidic ingredient; fruit juice, sour milk or molasses, to produce CO2.

1. I can't see how it would make your waffles fluffier than conventional modern rising agents, even if you did get your chemistry right. You still need to get your CO2 from somewhere and substituting your bicarb for lye actually removes this element. You would need to rework your entire recipe, I think.

2. Yes. Without doubt. More than likely it will degrade the taste of what should otherwise be a delicious dish. Alkaline foods are well known to have a bitter after taste (think kale and broccoli). Even scones made with a little too much baking soda can leave your mouth tasting and feeling like you've just had your annual clean and scale at the dentist.

3. While lye is used as a cooking agent in some instances, even the food grade solutions are extremely caustic, and, undiluted, are actually classed as poisons in some instances. It is corrosive to the body, especially mouth, throat and stomach, and can cause serious damage to the eyes. This may be stating the obvious, but best to assume ignorance and work up from there. Apart form mooncakes, I am not aware of a dough recipe (or anything else for that matter) that incorporates lye within the dough itself. Unless you have experience handling this ingredient in the kitchen, alternatives are recommended. I cannot tell you how you would determine whether your 'lye reaction' is complete within the dough; certainly gauging the completion of 'the rise' would not be sufficient, and the cooking process may need to be adjusted to accommodate this. Mooncake dough, for instance, is allowed to sit overnight, and even for up to 3 days before cooking. Too long to wait for my waffles!

For your interest, there is a very good comparison of various traditional and modern leavening agents here. Interestingly, the author concluded that the best agent overall was baking soda. Just like modern research chemistry in the lab - someone has done the reaction already.

• Thanks for your great answer. I make pretzels fairly regularly with lye solution, so I'm comfortable using this hazardous substance to some extent. Regarding safety, I'm still not clear how long lye has to process (or in what way) to become safe. For example, I dip my pretzels in lye and bake them within 15 minutes for 15 minutes. When they come out of the oven they are (empirically) safe to eat. I don't know why - oven heat? Reacting with dough somehow? – Steve Midgley Feb 9 '16 at 2:43

The leavening effect of baking soda (sodium bicarbonate: $\ce{NaHCO3}$) is not from its basic/alkali nature, but from the carbon dioxide produced from the decomposition of carbonic acid ($\ce{H2CO3}$) produced from the reaction of the bicarbonate ion ($\ce{HCO3-}$) in the sodium bicarbonate with acids in the food. The more acid, the more vigourously the sodium bicarbonate will react.

Lye (typically sodium hydroxide: $\ce{NaOH}$) is also basic/alkali, but when the hydroxide ion ($\ce{OH-}$) reacts with acids, it forms water ($\ce{H2O}$). No carbon dioxide gas is formed, and thus no leavening of the food is possible. Yes, lye is a stronger base than sodium bicarbonate, but as the leavening doesn't come from the base-ness, you won't get any increase in leavening.