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I’m looking for info on a portable matza oven to be used in a travelling pesach expo. either propane or gas fired.
You really need to define portable (and whether you want to make real matzah). Forno Bravo makes wood fired pizza ovens mounted on trailer chassis.
My shul bought a steel matzah oven from Israel. It could easily be mounted on a trailer or pickup truck. It is fueled by Propane tanks. You could also probably put wheels on it. It is a very simple steel box design, on four steel angle-iron legs.
You need a really hot oven (like 900 degrees) so that the matzah cooks almost instantaneously to avoid any chashash of chometz.
If you have any recourse to use electricity, you can fit my rig in a suitcase. A large double saluf pan, basically two cheap aluminum pots with electric oven elements top and bottom. It is very light, but I get better results using a cordite stone rather than an aluminum tray. That limits the space to one and a half standard hand matzo. Total wattage is around 2k. I run it off two different 16 amp outlets.
Also a standard pizza oven without its legs is not that large. For matzos, you might need to beef it up with some stone, and redo the gas orifices for tanked gas. Remember that there is a balance between fire power and thermal retention mass. Too much mass gets heavy really fast.
I don’t know the actual amount, but I just called the shul’s office, and they gave me the following information:
The place we bought it from last year is now advertising publicly. It is called “Tanurei Yerushalayim”. They are available in two sizes. It comes with both orifice valves to work with Propane or Natural gas. If you order it enough in advance, they ship it by boat from Israel. Otherwise, it has to get sent by air.
My shul bought the larger one last year, and had it shipped by air. The shipping was about $800, but I have no idea how much the oven was. Maybe it was 2 or 3 thousand. It is not really complicated, and might even have been much cheaper than that.
It is a well made serious oven, not a toy. I helped them transport it, assemble it, set it up, and used it with them last year. We had it on almost the lowest temperature it could go, and it was way hotter than a pizza oven. The oven floor has stone plates, and the oven body has a domed roof to concentrate the heat, just like a brick oven. It is an excellent choice for any Matzah bakery, and the small one (though I have never seen it) might be good for a portable set up too.
One warning though – the heat underneath and around the oven gets dangerously high. Don’t go putting one of these in your basement, on your wooden deck, or anywhere NEAR anything meltable or flammable. That does not mean you cannot use it indoors. We used it inside a storefront. You should be fine as long as you put it near a door or window, have fans and plenty of ventilation, and most important, the floor under it must be concrete, metal, stone, or something equally heat proof. We ended up laying down cement boards (aka. wonderboard) under it (after the vinyl tiles melted!)
Also (just as a curiosity) it consumes propane faster than a normal BBQ grill. The small 20lb cylinders are not designed to release the gas so quickly, and they froze up. So we had a few and alternated them. It was just interesting. We also kept the tank in a tub of water, but I am not sure what exactly that accomplished. It probably helped insulate or defrost them?
The two approaches depend on what you are trying to make. If you want a real matzah bakery, just portable and small scale, you need a real gas-fired oven. Twisted’s idea sounds like an electric skillet (think of a crepe maker at a fancy wedding). Similarly, you could look for a table-top electric ‘dutch’ oven, which may barely be enough if you just want to demonstrate what a matzah looks like at a show, kiruv meeting, or for a classroom. The results might not necessarily be baked fast enough to actually be kosher l’Pesach.
If you bake matza on erev Pesach, your main problem is not the oven, it is the leftovers and everything. You have to get rid of all the wet flour residues, as well as any doubtful that you think are in the oven already but might not be going to cook properly, well before the 18th minute; and “getting rid” in our house (not in a matzo bakery) must be carefully thought out and arranged, also it does take some time. I don’t know how many people are working on it – this is a very important variable. I would advise to practice before Pesach baking matza with the oven or appliance you plan to use. Of course, the hotter the better.
daniela, the procedure for erev pesach is to state that everything that is left over/falls/crumbs etc. will be batel before they become hametz. If you have a wood fire going, then of course you sweep up and toss it in the fire. You could also flush it down a drain. It helps if you are a micro op and your cycle is way shorter than 18 minutes.
Saluf pan: Saluf is a teimani fluffy pita type bread made in present times in a cheap aluminum deep fry pan, with a electric element added, and a plug, very much like a free hand manual toaster, but with more wattage. It can be used over a skillet on a stove, or stand alone with just another fitting lid. The single heater set-up is used with the heat above the bread as a boiler.
For (ashkenazi)matzos, you want heat from above and below, so the saluf pan over a heated skillet, or a double saluf pan with heater top and bottom. My setup is 54cm round, and I do one, or two matzos per cycle, and my matzos are small, heavy whole wheat. If you can do only one at a time a smaller version 25-27cm fits on a stove top like a large pot. These things weigh almost nothing. I don’t know what you would do to make them suitable to 110V. Here you can get oven elements made to order. The down sides are that like a pizza oven, you don’t see the baking, you need to know your dough and oven and have the timing down, otherwise the matzos can be easily incinerated. They are unspeakably cheap junk, and the labels indicate they are made in Jordan or in the PA. I have plans to build my own, in welded steel, with rectangular elements to get away from the cheap.
For the handy, anything that can bake a pita, with some slowing down, or heating up, can bake the much thinner, less water containing matzo. I have seen a table top pita baker that had a metal mesh link belt and internal toaster arrays. The wet pitas were fed onto the belt, and they came out the other side baked and puffed up. If the mesh were narrowed to hold a matzo, either slowing the transit or beefing up the heater would do the job, and the belt always moving past the heaters is continually kashered.
Thank you a lot twisted pretzel. May I ask you when is it the latest one may batel the wet flour before it becomes chometz. Also, this is a big help as it guarantees we won’t own or benefit in any way, but still there is a problem as it may contaminate. I think if there is no wooden fire, the easiest is throwing in the toilet, pouring bleach or similar, and flushing, then washing everything we used with nonedible detergent, all this well before 18 minutes. One can do very quickly, of course one at a time.
We are not doing, this is just discussion for its own sake. Thank you a lot.
daniela, it is called a t’nai lehaba. As after it becomes chametz you no longer have rights to it and cannot batel, you state before you start that what may become hametz, should be mevutal ahead of time. Practically that is 18 minutes. When I wash out my bowl and stuff, after it is down the drain, I don’t concern myself with it, and as a plumber, I can tell you that down the drain is icky enough without the bleach or nonedible? detergent. My process is paper towel and latex glove intensive and what gets washed must get dried. And being Brisk-oriented, I have big medicine in Erev Pesach matzos, I just do it for the Halachic thrill. For that run, we torch the paper and sweepings, and do without the gloves. And in certain dry places, like Denver CO, you don’t own what goes down the drain, i.e. you may not recycle to grey water or toss it out on the lawn. Western water rights and the like.
daniela, it is called a t’nai lehaba. As after it becomes chametz you no longer have rights to it and cannot batel, you state before you start that what may become hametz, should be mevutal ahead of time. Practically that is 18 minutes. When I wash out my bowl and stuff, after it is down the drain, I don’t concern myself with it, and as a plumber, I can tell you that down the drain is icky enough without the bleach or nonedible? detergent. My process is paper towel and latex glove intensive and what gets washed must get dried. And being Brisk-oriented, I have big medicine in Erev Pesach matzos, I just do it for the Halachic thrill. For that run, we torch the paper and sweepings, and do without the gloves. And in certain dry places, like Denver CO, you don’t own what goes down the drain, i.e. you may not recycle to grey water or toss it out on the lawn. Western water rights and the like.
Thank you a lot twisted pretzel I am very honored to talk to someone who actually did. How do you do in regards to water? Or are you able to obtain water which has a minhag to be used for matza, and have it resting before you use? And may I ask why do you say 18 minutes, I thought there is no chometz earlier than 18 minutes if we mix Pesach flour and water in a clean manner, but if it is not clean (say, what falls on the floor, maybe there is dirt? maybe salt?) then it may be quicker, do I have this wrong? Thank you again.
Daniela: My water in drawn at sunset from a spring outside Jerusalem. I usually take two 1.5 liter bottles, but I have never used more than one. About the stuff becoming faster, there is actually a ruckus being raised by somebody in a Jerusalem Torah think tank, that 18 minutes is a mistaken measure, and the time is much longer. Indeed, you can mix flour and water and just watch it, and the classical halachic signs of chametz do not show up for a really really long time. As I understand the chametz process as a bio-chemical process, I don’t think the dust on the floor will speed things up, as it absorbs moisture, and salt definitely hampers yeast activity and it is the native yeasts that are critical to the hametz process.
The bitul concept is similar to the hefker concept. You can renounce ownership of what you do own but not of what you do not own. Similarly, I can declare the dough remnant ownerless and meaningless only while it is still not chametz and thus forbidden and not mine to make such stipulations about. And one can make these stipulations to start and stop as one likes, or in this case, the governing rule is set in place prior to its need, just as long as it is not yet chametz. In my case of a micro op, my cleanup is done, averagely at the 7 minute mark, at 11 minuteas I can be preparing the next batch. Also, what falls to the floor, provided it is tiny, the more the dirt, the more it is actually self batel. That the ants might eat what I miss sweeping is not a concern. And the mevutal stuff that we pick up and dispose of , is just because of the virtue of, and need for cleanliness.
Thank you a lot, you and your family should have countless blessing from your baking on Erev Pesach. It is an unforgettable experience, it’s very moving and it’s unfortunate that we are so ignorant it’s unfeasible. I recall being told that 18 minutes is really a spiritual number and a fence against the strict prohibition, that we don’t get chometz gamur at 18 minutes, but that we have to go by the 18min and be careful and as you wrote, in 7-8 minutes (and a lot of sweat) it’s finished, if there are enough people one can do a little bit quicker (6 min or so, if I recall right). As for the salt, I remember asking as a child, it’s clear that old-style salt is wet and thus we never use in Pesach cookies (those we make with flour and egg / oil / honey etc) but modern salt, what is wrong with it, and could we not put it in the oven so we make sure it’s dry? Even non-shmura flour (fit for Pesach) may have a little bit of humidity and we are not concerned. I was told this too is a spiritual concept, and I was told something about not using salt and water to bake (which we may imagine is ok to do in a similar way it is possible to add fruit juice or egg or wine etc. to matza – my grandfather was Sefardi) lest it quickens the process. I can’t remember the details, years later I asked Rabbis and I was told we don’t use salt, not even if it’s completely dried, to bake Pesach cookies; and in regards to matzot and salt, my husband has never heard about it, he was not told is forbidden nor is permissible. Sadly there is no one left to ask, from either families. Thank you again.
Shavua tov Daniela. Thank you for the kind blessing. Never despair of ignorance. It has an excellent cure rate.
The primary reason for not using salt in matzo is that it renders the matzo Matzo Ashisra, or “fancy bread” and matzo must reflect lechem oni. Secondarily, anything whose effect were unknown were avoided in matzo.
I consider myself fortunate to have had a good science background, and to have lived in a time and society where science is held in esteem, as it functions as a handmaiden to Torah. I was also fortunate to cross paths with Rav Blumekranz ztk’l. In some of his older publications he listed the physical process of water+b amylase= starch to sugar conversion= native yeast nutrient+ gas and alcohol release trapped as bubbles in gluten=chametz. This process is stymied by salt, but that was maybe not recognize or accepted.
In halacha there is a mention of kimcha divshuna. This was flour made from roasted grains that was recognized as not subject to chametz. Of course, heat destroys the enzymes, and the yeasts.
It was forbidden a long time ago because of the risk of a non complete roast. Flour (cake meal) and meal made from matzo is used just in this way, and it cannot become hametz, unless you reintroduce a composite of enzyme and yeast. All this works until you say that chametz is only a spiritual thing.
I also found a Rashi recently that would seem he held kimcha divshuna was malt, and I have strong theory that the malting process is exclusive of the chametz process.
The phone number for Tanurei Yerushlayim (Jerusalem Ovens) in Israel is: (011) 972 545 512-800. I don’t think they speak English, so if necessary have a translator call for you.
It is probably too late to get one in time for this year, but since this post was started last year and is still going, it is likely that it will still be seen next year, or someone may take down the number now, to buy one next year.
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