Tequesquite

Question: Where to get Tequesquite?
I understand that a substance called tequesquite will puff the corn mase during cooking tamales. Where can I but this and what its is?

Answer: Tequesquite is an alkaline mineral deposit that is used when making tamales and bunuelos. (Some people boilit with tomatillo husks and use the water when mixing both doughs to obtain the same effect.) Tequesquite is widely available in spice counters of most Mexican grocery stores and through mail order.(See Sources on the web site.) posted here on our web site

I’m going to contact Harold McGee, a food scientist, and see if he has any thoughts on how and why this works.

Dear Harold:
How are you? Hope this finds you well.
I have an Ask Zarela section on my web site, www.zarela.com and was recently asked what it is about tomatillo husks when boiled that makes bunuelos and tamales puff up and about tequesquite that does the same to tamales. Do you perchance know? I would so appreciate an answer and will post it on the web site with proper credit of course.

Dear Zarela,
Good to hear from you! Sorry for the delay, but I’ve been out of town. I’m afraid I don’t have immediate answers to your questions, but they’re very interesting to me, and with a little more information I might be of some help.
Tequesquite is mineral lime, which is alkaline like baking soda. If you mix it with an acid ingredient into the masa, then the reaction would give off carbon dioxide gas, and that would leaven the dough. Do the masa ingredients include something acid, a fruit or vegetable? As for the tomatillo husks–how are they handled? Do you boil them in water and then use the water for the dough? Or do the husks end up incorporated in the dough? Do you use just one or two, or a bunch? It’s possible that they contain some acid, but I’ve never tasted the husks. Are they sour?
Regards,

Dear Harold:
Thanks for answering my letter. I just looked in a marvelous book,Presencia de la Comida Prehispanica, by Teresa Castello Yturbide and they say that for teqeusquite to be a leavener, one should bring 10 tomatillo husks and 1 cup of water to a boilwith a small piece of tequesquite and cook until this dissolves. Then remove from heat; let cool and settle. It should be then strained before using. Your explanation makes sense because the husks are mildly acidic — I just tasted one.
According to this book, tequesquite is also used when cooking beans to soften them and to retain the color of nopalitos and other green vegetables. It can also be added to pulque to make vinegar and heated but not brought to a boil. It should ferment in 3 days.
May I post your explanation?

Dear Zarela,
Given what the Yturbide book says, my theory must be incorrect! The problem is that if you boil the husks and lime together before using the water for the dough, the acid and alkali will react during the boiling to create gas, and the gas will escape before it can leaven the dough. Another possibility is that the lime helps dissolve the husks’ cell walls, which contain pectin and similar thickening agents. In that case, the thickeners might loosen the compact, concentrated dough structure (mainly protein and starch) and make it easier for trapped air bubbles to expand during the cooking. In a way this makes more sense than my original idea, because masa dough is already quite alkaline from the nixtamalization, so you shouldn’t really need any tequesquite.
I’ll try to do an experiment this weekend to see if I can tell what might be going on. In the meantime if you’d like to post my theories and doubts, please feel free–someone out there may be able to enlighten us! And thanks again for such an interesting question.
Regards,

My co-author, Anne Mendelson, weighs in:

Dear Zarela,
Seems to me that there might be more to the action of tequisquite and tomatillo husks than just an acid/alkali reaction producing carbon dioxide. The tequisquite contains a lot of different minerals — it isn’t just potassium carbonate or sodium bicarbonate or any other one alkali in purified form. Same for the cascara de tomatillo. I wonder who would know exactly what IS in the husks. Are they similar to groundcherry husks or Cape gooseberry husks? I wouldn’t have thought that they contained much pectin (the fruit itself has a lot of pectin), but I don’t really know.

Some one else pitches in:

I read your section about tequezquite and que use of it and tomatillo husk to puff up tamales masa. Maybe you find interesting that acording to a tamales recipe posted by Universidad de Guadalajara on the address http://mexico.udg.mx/cocina/maiz/tortillas1.html you should use one or another, no both of them at the same time, to puff up the masa