“No present which ye bring near to Jehovah is made {chametz/chometz} fermented, for with any {seor} leaven or any honey ye perfume no fire-offering to Jehovah” (Leviticus 2:11, Young’s Literal Translation).
(Sometimes chametz may be permitted — specifically when in bread לֶחֶם lechem (bread) — only when the leavened bread is for less important purposes (Lev. 7:12-13). But no type of fermentation whatsoever is appropriate for the very holy burnt offerings.)
This verse (Lev. 2:11) is also relevant when considering the type of wine suitable for nesek ( poured offerings / libations) at the Jewish Temple. Maimonides (writing in 12th century A.D.) noted the Maghrebi Jews understood Leviticus 2:11 to exclude even a tiny amount of yeast put into a large volume of wine. Nevertheless, others preferred instead to disregard this verse of Scripture.
“We may only make Kiddush upon wine fit for libations on the altar. Hence, if honey or leaven was mixed [with the wine]—even if only a drop like mustard seed into a large barrel—we can not make Kiddush on it.” (Maimonides, Mishneh Torah, Sabbath 29.14, referring to Leviticus 2:11)
Excluding leaven (yeast) would be to avoid fermentation.*
An obligation to sin? What?!
But a certain rabbi Rava unwisely ignored various Scriptural warnings against intoxication (e.g. Deut. 21:20; Prov. 23:31) – even daring to proclaim an “obligation” to sin against God! For example: “Rava said: A person is obligated to become intoxicated with wine on Purim until he is so intoxicated that he does not know how to distinguish between cursed is Haman and blessed is Mordecai.” (Megillah.7b.7)
*(See also Num. 6:3 which lists both yayin and chometz yayin (wine and fermented wine) because Nazarites have neither.)
New Testament: obligation to clean out the yeast, evil, wickedness!
Again in the New Testament, we are reminded of leaven excluded in Lev. 2:11:
“cleanse out, therefore, the old leaven, that ye may be a new lump, according as ye are unleavened, for also our passover for us was sacrificed — Christ, so that we may keep the feast, not with old leaven, nor with the leaven of evil and wickedness, but with unleavened food of sincerity and truth. I did write to you in the epistle, not to keep company with whoremongers — and not certainly with the whoremongers of this world, or with the covetous, or extortioners, or idolaters, seeing ye ought then to go forth out of the world — and now, I did write to you not to keep company with [him], if any one, being named a brother, may be a whoremonger, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner — with such a one not even to eat together.” (1 Cor. 5:7-11, YLT)