Making matzah at home

Question

This is a follow-up question to 18 minute matzah cutoff (and see also Where does the notion that the *entire* matza process must be done in under 18 minutes come from?)
I know this isn't the standard method of making matzah these days. But now I'm asking a practical question: Is there anything wrong with making matzah in home in your regular oven? Here's one description of what I've tried, how it would look:

1. First run my oven on self-cleaning cycle, which seems to be acceptable to prepare it for (regular) Pesach use, according to the Star-K and perhaps others.
2. My oven goes up to 550 F (288 C). (Igros Moshe (OH 153) says that the cooking surface needs to be ליבון קל, which is < 500 F which burns paper, and that the cooking device should surround the matzah, not just be on the bottom. The oven seems to meet those requirements.)
3. Take out the bottom grate inside to make room. Preheat it to that temperature. Put a wide (18") piece of tinfoil on the bottom of the oven so that it is hot already when the matzah goes in.
4. Take shemurah matzah flour and מים שלנו. (Of course, when I'm practicing it's with (probably chametz) flour off the shelf and water from the sink.)
5. Knead one single cup of flour and around 5 tbsp water, quick as I can, roll it out with a clean rolling pin.
6. Use a fork to make holes in the matzah (there are better faster tools available).
7. Put it on another piece of tinfoil to help carry it, and put that on top of the hot tinfoil in the oven. (The poskim discuss baking matzah on paper which will burn up, and say that the paper not being hot won't matter, it's too thin and too quick. I assume the same is true of tinfoil.) It is now doubly separated from the oven floor in case something goes wrong. [Addendum - they allow paper b'dieved for that reason, but don't seem to allow it lechatchilah.]
8. At this point around 10 minutes have passed, since I'm not so competent.
9. It now takes around 10 minutes to bake. See the linked discussion above that that time should not matter.
10. Pull the matzah out using the tinfoil.
11. Clean everything thoroughly. Add new tinfoil in oven if you want to make another matzah.

Is this lechatchilah, b'dieved, or no good at all?

Answer 1

#NotARabbi, but there is nothing wrong with baking at home. Jews did that for centuries. Kudos for thinking this through a bit. A few tips from many years of baking at home:

1. I suggest buying firebrick from a masonry supply store and after kashering the oven, line the bottom of the oven with them. These will hold heat much better than the thin metal on the bottom of an oven
2. I'd practice at least once with shmurah flour. It behaves very differently than supermarket flour.
3. Weigh your ingredients. Crispy matzah typically has very low hydration (last year's flour required 46% -- meaning that 100g of flour only needed 46g of water).
4. Parchment paper is your friend. Roll out on parchment paper and/or between pieces of parchment paper. It will help reduce sticking to the rollers and rolling surface.
5. A fork works great.
6. For transfer to the oven, buy a thin wooden dowel from a hardware store. Drape the matzah on the dowel and "unroll" it onto the firebrick.
7. Suggest using disposable for nearly everything (bowls, plastic table surfaces, forks, etc.). Except for the rolling pins (and dowels). These worked well: https://www.amazon.com/gp/product/B082WF6MG2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Be sure to sand, rinse, and dry thoroughly.
8. Matzot will bake in much fewer than 10 mins (4-5 min in a home oven IIRC)
9. Review all halachot ahead of time. Little things like "don't bake near windows/sunlight" and "prepare dough in a different room than the oven" and things like that.
10. Make a "pre-flight" checklist. It's easy to forget a critical step, and a checklist prepared ahead of time is helpful for making sure you're not missing a step.
11. Involve a friend or two. It's a lot of work, and it can be easier with helpers.
12. Involve children in halachically permissible ways. Under bar/bat mitzvah are more limited in what they can do, but it is an amazing experience for them.

Answer 2

I'm not a Rabbi, but I've been cooking matzah for half a decade now. I also have a strong bias AGAINST using things that are disposable. Most of our people for most of our history could never afford disposable cookware or cutlery. So if they were able to make matzah without it, then it shouldn't be considered an extreme opinion that we should be able to as well.

Everything you've stated is fine but I think you are still over-complicating things. Matzah was never supposed to be complicated, it was supposed to be the easiest and quickest of breads. In Europe and the Middle East they used to pay out of work women, elderly, and children to bake matzah because of how simple it is. Now we've reversed and say only the most learned of us should ever even attempt. So I'll go through your points one by one to see if I can add anything useful to the discussion and simplify things.

1. First run my oven on self-cleaning cycle, which seems to be acceptable to prepare it for (regular) Pesach use, according to the Star-K and perhaps others.

Sounds great. Everything should be kashered for Pesah

2. My oven goes up to 550 F (288 C). (Igros Moshe (OH 153) says that the cooking surface needs to be ליבון קל, which is < 500 F which burns paper, and that the cooking device should surround the matzah, not just be on the bottom. The oven seems to meet those requirements.)

There is no minimum temperature for ovens. Actually one does not need an oven, one can cook directly on the coals of a fire or on a ceiling tile heated by a fire. In my experience matzah is simpler to make on a hot cooking surface such as a saj (overturned wok), or cast iron skillet, pizza stone, etc. Pizza Ovens are also great and even Nusach Teiman sells a double sided electric oven with bread pillow they recommend for matzah at home.

Relying only on hot air moving around in a European oven to cook matzah dries it out.

3. Take out the bottom grate inside to make room. Preheat it to that temperature. Put a wide (18") piece of tinfoil on the bottom of the oven so that it is hot already when the matzah goes in.

As others have mentioned I would recommend a pizza stone. I think tinfoil will be too thin to adequately hold and pass on heat to make matzah cook faster

4. Take shemurah matzah flour and מים שלנו. (Of course, when I'm practicing it's with (probably chametz) flour off the shelf and water from the sink.)

I disagree that regular flour is "probably" chameitz. At best I'd call it "doubtful" or "questionable" hameitz. The "tempering" done in our days is raising humidity in huge silos, a far cry from boiling wheat berries as was the practice of everyone during the times of the Gemera and poskim.

A second reason is offered by Rabbi Moshe Heinemann, STAR-K’s Rabbinic Administrator. He posits that there is an ironclad scientific basis for considering tempered grain to be safek [not actual] chometz. Millers need the grain to be dry enough to mill efficiently and they therefore set the moisture level of incoming wheat to no more than 14%. Mr. Dengler points out that wheat that arrives at their mill with a higher moisture content is routinely rejected. When wheat has been properly dried, either in bins at grain elevators or at the farm, it is very stable and can be stored for very long periods of time without any germination – in some cases, even for years.

Source: https://www.star-k.org/articles/kashrus-kurrents/13298/controlling-your-temper/

5. Knead one single cup of flour and around 5 tbsp water, quick as I can, roll it out with a clean rolling pin.

I do not recommend kneading as quick as you can. This leads to halakhic complications such as gebrochts and other issues down the line. One should knead the dough until it's ready and has enough water. Do NOT add additional flour to make it nonstick. For making matzah you can always add water, you can't always add flour. Every batch of flour comes with differing levels of hydration so the amount of water needed will always vary slightly

6. Use a fork to make holes in the matzah (there are better faster tools available).

Completely unnecessary and I believe takes away from "this is the matzah we ate..." we originally made matzah in haste, and definitely didn't take time to poke holes in it. We also no longer use molds to make matzah decorative even though it doesn't add much time for the same reason of we are supposed to make it in haste. For those worried about "swelling/נפוח" please see the comments

7. Put it on another piece of tinfoil to help carry it, and put that on top of the hot tinfoil in the oven. (The poskim discuss baking matzah on paper which will burn up, and say that the paper not being hot won't matter, it's too thin and too quick. I assume the same is true of tinfoil.) It is now doubly separated from the oven floor in case something goes wrong. [Addendum - they allow paper b'dieved for that reason, but don't seem to allow it lechatchilah.]

Most sepharadim cook on a hot surface and use a bread pillow for transporting the dough such as this: https://karoutexpress.com/product/bread-pillow-for-saj/

When I first started making matzah I built my own tandoori oven and made my own bread pillow using some rags rolled up, covered them by a 100% cotton cloth. you put the bread on the pillow and you can slap it onto your hard surface. To "kasher the pillow" you then touch the pillow to some other part of your hot surface to burn up/cook whatever microscopic bits of dough that stick to the cotton. Then after you're done baking for the day you take off the cotton cloth and throw in the washing machine.

8. At this point around 10 minutes have passed, since I'm not so competent.

Even if you spent all day kneading it would not reflect on your competency. When I teach others to bake I always have them work in pairs, one person always kneading and the other does the baking. This satisfies all opinions and helps prevent accidents. But often the kneader is kneading for well over 10 minutes.

9. It now takes around 10 minutes to bake. See the linked discussion above that that time should not matter.

10 minutes to bake seems like a long time. I wonder if your tin foil is not "thick enough" to hold and transfer the heat well to reduce cooking time. I return to the suggestion for a pizza stone. Not that you need to cook faster, but you would probably also get more consistent cooking.

10. Pull the matzah out using the tinfoil.

Sounds fine

11. Clean everything thoroughly. Add new tinfoil in oven if you want to make another matzah.

This seems quite wasteful but it'll work. People often want to start with a new fresh clean surface for each matzah, but as long as your pizza stone/saj/oven maintains its temperature then any crumbs or leftover bits of matzah won't be hameitz.