(ג) הביאו לפניו מטבל בחזרת. עד שמגיע לפרפרת הפת. הביאו לפניו מצה וחזרת. וחרוסת. ושני תבשילין. אף על פי שאין חרוסת מצוה. רבי אליעזר בר צדוק אומר. מצוה. ובמקדש. היו מביאים לפניו גופו של פסח:
(3) [Then] they set [food] before him. He dips the lettuce before he reaches the course following the [unleavened] bread. [Then] they set before him unleavened bread, lettuce, charoset and two dishes, although the charoset is not compulsory. Rabbi Eliezer bar Tzadok says: It is compulsory. And in the Temple they used to bring before him the body of the Passover-offering.
1) Why do we have charoset on the seder table?
צריך לשקועיה בחרוסת משום קפא ... ודילמא לעולם אימא לך לא צריך לשקועיה וקפא מריחא מיית ... ואמר רב פפא לא נישהי איניש מרור בחרוסת דילמא אגב חלייה דתבלין מבטיל ליה למרוריה ובעינן טעם מרור וליכא
One must submerge it in the ḥaroset, due to the kapa in the lettuce... Actually, I will say to you: According to the halakha, one need not submerge the lettuce in ḥaroset, and the kapa dies from the smell of the ḥaroset... And Rav Pappa said: A person should not leave bitter herbs in the ḥaroset for a lengthy period of time, lest the sweetness of the spices in the ḥaroset nullify its bitterness. And the bitter herbs require a bitter taste, and they are not bitter when marinated in ḥaroset.
רבינו חננאל פסחים קט״ו ב
קפא- תולעת, דתניא בתוספתא:
Rabbeinu Chananel on Pesachim 115b
Kappa- A worm, as is taught in the Tosefta
One must dip it in the charoset because of the Kapa- A poison in the lettuce, since the burning effect of lettuce is the result of a poison that needs to be neutralized, just like with onions.
2) Is everyone on the same page about this?
The mishna states that they bring the ḥaroset to the leader of the seder, although eating ḥaroset is not a mitzva. The Gemara asks: And if it is not a mitzva, for what reason does one bring it to the seder? Rabbi Ami said: It is brought due to the kapa in the bitter herbs, which is neutralized by the ḥaroset. In this regard, Rav Asi said: The remedy for one who ate the kapa in lettuce is to eat a radish. The remedy for the kapa in a radish is leeks. The remedy for the kapa in leeks is hot water. A remedy for the kapa in all vegetables is hot water. The Gemara comments: In the meantime, while one is waiting for someone to bring him the remedy, let him say the following incantation: "Kapa, kapa, I remember you, and your seven daughters, and your eight daughters-in-law."
The mishna states: Rabbi Elazar, son of Rabbi Tzadok, says that eating ḥaroset is a mitzva. The Gemara asks: What is the nature of this mitzva? The Gemara answers: Rabbi Levi says: It is in remembrance of the apple, as apple is one of the ingredients in ḥaroset. The verse states: “Who is this who comes up from the wilderness, reclining upon her beloved? Under the apple tree I awakened you” (Song of Songs 8:5), which is an allusion to the Jewish people leaving Egypt. And Rabbi Yoḥanan says: The ḥaroset is in remembrance of the mortar used by the Jews for their slave labor in Egypt. Abaye said: Therefore, to fulfill both opinions, one must prepare it tart and one must prepare it thick. One must prepare it tart in remembrance of the apple, and one must prepare it thick in remembrance of the mortar.
It was taught in a baraita in accordance with the opinion of Rabbi Yoḥanan: The spices used in the ḥaroset are in remembrance of the hay that our forefathers used for building in Egypt, and the ḥaroset itself is in remembrance of the mortar. Rabbi Elazar, son of Rabbi Tzadok, said: When selling ḥaroset, the small shopkeepers in Jerusalem would say as follows: Come and take spices for yourselves for the mitzva.
In Masechet Sotah (11b) we read that the women of Israel would give birth under the apple trees without any pain, which allowed them to give birth without the Egyptians knowing.
One must prepare it tart and one must prepare it thick- In the Yerushalmi it also says that it is supposed to be a remembrance of the blood, and therefore we call the act "dipping" like we call it with a liquid. This is a matter that the people follow, adding wine and vinegar at the time of eating to make the consistency more liquidy. I have found additional positions in the Gaonim which say that charoset should be made of the fruits that greeted the Israelites when they came into the land of Israel, as the Song of Songs mentions apples, pomegranate, fig, dates, nuts and almonds.
3) How does this play out in halacha?
(א) ... וְאַחַר כָּךְ יִקַּח כַּזַּיִת מָרוֹר וִישַׁקְּעֶנּוּ כֻּלּוֹ בַּחֲרוֹסֶת, וְלֹא יַשְׁהֶנּוּ בְּתוֹכוֹ שֶׁלֹּא יְבַטֵּל טַעַם מְרִירוּתוֹ, וּמִטַּעַם זֶה צָרִיךְ לְנַעֵר הַחֲרֹסֶת מֵעָלָיו, וִיבָרֵךְ עַל אֲכִילַת מָרוֹר וְיֹאכְלֶנּוּ בְּלֹא הֲסַבָּה, וְאַחַר כָּךְ נוֹטֵל מַצָּה שְׁלִישִׁית וּבוֹצֵעַ מִמֶּנָּה וְכוֹרְכָהּ עִם הַמָּרוֹר וְטוֹבְלָהּ בַּחֲרֹסֶת. הַגָּה: וְיֵשׁ אוֹמְרִים דְּאֵין לְטָבְלוֹ, וְכֵן הוּא בַּמִּנְהָגִים וְכֵן רָאִיתִי נוֹהֲגִין.
Afterwards you should take a kazayit of maror and fully submerge it in charoset, but you shouldn't leave it in there because it might nullify its bitterness, and for this reason you need to shake off the charoset from the maror. You then must say the brachah, "al achilat maror", and you should eat it without reclining, and then afterwards you should take a third piece of the matzah and break it in half, and make a sandwich with the maror in the middle, and you should submerge this sandwich in charoset.
Rama: There are those who say that you shouldn't dip it, and this is a minhag that I have observed.
(יג) וישקענו כולו - כדי להמית ארס שבתוכו.
You should fully immerse it: So as to kill the poison that is inside.
4) What about in more "kabbalistic" halacha?
שולחן ארוך הרב:תעג:לב
החרוסת צריך להיות עב לפי שהוא זכר לטיט שנשתעבדו בו אבותינו ואח"כ צריך לרבך אותן במשקה זכר לדם ויש לרכבו במשקה אדום כגון חומץ או יין אדומים ויש לעשות החרוסת מפירות שנמשלו בהם כנסת ישראל תחת התפוח עוררתיך. כפלח הרמון רקתך. התאנה חנטה פגיה. אמרתי אעלה בתמר. אגוז אל גנת אגוז ירדתי. ושקדים על שם ששקד הקב"ה על הקץ לעשות. ומעיקר הדין יכול לעשותו אפילו מירקות ולרכבו אפילו במים ושאר משקין אבל עכ"פ צריך ליתן בתוכו דבר שיש בו קיוהא כגון תפוחים או יין וחומץ זכר לשיעבוד שהיו משתעבדים בישראל עד שהיו שיניהם קיהות
לג- וצריך ליתן בתוכו תבלין הדומין לתבן כגון קנמון וזנגביל שאינן נדוכין הדק היטב ויש בהן לאחר הדיכה חוטין קשין וארוכין קצת כמו תבן זכר לתבן שהיו מגבלין בתוך הטיט
Shulchan Aruch Harav 373:32-33
32: The Charoset needs to be thick, as its a remembrance of the mortar that our ancestors toiled in throughout their slavery, and then afterwards you need to mix in liquid as a remembrance of the blood. Thus, ideally the liquid you mix in should be red, like wine or vinegar. The charoset should be made of the fruits that greeted the Israelites when they came into the land of Israel: apples, pomegranates, figs, dates, nuts and almonds. From a pure legalistic sense you could make it instead from vegetables, and mix in water or any other liquid, but in any event you need to put in something which has tartness (קיוהא) , like apples, wine or vinegar as a remembrance of the slavery with which they subjected our ancestors until their teeth became blunt (קיהות)
33: You need to put spices into the charoset that look like straw, like cinnamon and ginger, which aren't chopped into tiny pieces and they have strong and long threads, which makes them look like straw, as a reminder of the straw which the Israelites had to put into the mortar.