THE PLACE AND ORDER OF MAKING THE MATZOT: SIX SECTIONS One should not knead in a sunny place and on a cloudy day, it is forbidden under any open sky because on a cloudy day, the sun is everywhere. REMA: and because of this, our custom is to be cautious to avoid kneading opposite an open window even where there is no sun, as it may become cloudy and one wouldn't realize.(T"H siman 193)Similiarly, there are those who are careful when moving the Matzot to the oven exposed to the sky, and similarly [when moving] the water and flour.(Haghaot Maimoni perek 5 in the name of SMA"K and MAHA"RIV). One should not approach the oven when kneading because of the heat of the oven.
One should not leave the dough unkneaded even for a moment. Whenever one is kneading it even the entire day, it will not leaven. If one leaves it unkneaded for the rate of [time passed when traveling] a 'mil', it's Chametz. The rate of a 'mil' is a quarter of an hour and a twentieth of an hour [18min/1mil]. REMA: and there is cause to be strict and expedient regarding the making of the Matzot, for there is concern that the suspensions will compound into the rate of a 'mil' or that it will be in a hot place where leavening is accelerated.(Haghaot Maimoni perek 5 and Mordechai perek "Ayloo Overeen"). After we kneaded the dough and heated it in our hands, if he leaves the dough unkneaded, it will immediately leaven. If one began kneading two [dough] simultaneously and it becomes apparent that one has leavened, the second has also leavened even if one does not see the signs of leaven. If it leavens to the extent that cracks form, even if they do not converge together rather one travels here and another travels there, it is considered cardinal Chametz. The one who eats this incurs 'Karait'. If there is a crack but it has faded face(meaning: a change in appearance toward whiter. ARUCH) like when a person's hair stands up, the consumer is exempt [from 'Karait']. REMA: and if the Matzah was formed and there is fear [that the standard] that the dough shouldn't succumb to leavening [will not be upheld], it is permitted to break [the form] and return to forming it so that the kneading will negate the leavening. However, better to be cautious initially.(MAHA"RIL in the name of Aguda and Rokeach)
If a woman is kneading the dough, she should shape it with water [but] not the water which she cooled her hands with because this water has been heated [from this action] and will leaven the dough. Rather she should have another vessel filled with water for shaping it.REMA: however, [where] she transgressed and did not cool her hands, it is permitted.(RAMBAM perek 5)
If [the dough] was kneaded after the beginning of when leaven becomes forbidden, the [hand cooling] waters along with other water used for washing the trough, one shouldn't spill them except in a sloped area so that they shouldn't accumulate in one place and leaven. REMA: and the vessels which one fixes for Matzo use, and the knife which one cuts the dough in portions should constantly be scraped at the time of production so that dough does not adhere to it. After, he should scrub them and dry them well, so that he may return and fix them for use a second time(MAHA"RIL). This is ideal compared to the practice of scraping it, for it's impossible to clean it well by scraping it. A strict person will scrape it and afterward will scrub it. (his own words). On Yom Tov, it's permitted for him to [clean them] via a gentile and if there is not a gentile, one should dispatch them to the cold or place them in the oven so the dough [on them] will bake. Troughs, where it's possible to put something inside them it's implied that it's permissible [to wash it] and other similar things. One should be cautious with a trough which one kneads in, that there shouldn't be any cracks or crevice which one will be unable to pick [all the dough out of] after kneading, and it will leaven and afterward when he returns to knead in the trough, it will mix with the dough(MAHA"RIL). one shouldn't place the trough on a pillow or wool cover when kneading, for it will heat the trough but on leather is permissible.
[If one] transgresses and kneads under the sun, the bread is permitted.
If the dough is [too] soft, one shouldn't add flour, rather one should make a small hard dough and mix it together with the soft dough. REMA: and one should distance the Matzot from the flour for the flour clings to them and go after into cooked food and leaven(Mordechai on the beginning of perek "Ayloo Overeen")