The Sugar Bowl, also known as the Vessel For Disaccharides, is a mysterious object mentioned repeatedly in A Series of Unfortunate Events.
The Sugar Bowl is said to be very important to V.F.D., both the fire-fighting and fire-starting sides, and the search for it is a key plot point in the later books of the series. There are many mentions of the sugar bowl and both sides of V.F.D. seem to be pursuing it; the Baudelaire orphans are eventually caught up in the search, although they have no idea why the bowl is so important. In Lemony Snicket: The Unauthorized Autobiography, it becomes apparent that it contains an object of great power or danger.
It is first mentioned in The Ersatz Elevator by Esmé Squalor (despite it appearing in the intro starting from Season 2.) In The Hostile Hospital, Lemony Snicket ponders whether it was necessary for him to steal it from her. It is implied that the sugar bowl is in Lemony's possession once more after he retrieved it from the pond next to the Hotel Denouement.
In the TV Series adaptation, it is revealed by Kit Snicket that inside the Sugar Bowl is a chemically engineered sugar that when consumed grants immunity to the Medusoid Mycelium. This would be supported by the VFD proverb, "Tea should be as bitter as wormwood and as sharp as a two-edged sword.", as in the series, wormwood is mentioned as a substitute to cure the Mycelium. However, this is not canon in the book series.
Lemony Snicket's narration has been pivotal in exploring the sugar bowl's relevance to the overall plot. Where the sugar bowl came from and when an item of importance was hidden in it are unclear; however, it is generally agreed that the earliest plot-relevant reference to it is in The Hostile Hospital. Lemony Snicket claims that he stole the sugar bowl from Esmé Squalor, but in The Grim Grotto, Esmé claims that Beatrice Baudelaire stole it from her.
In The Slippery Slope, Lemony Snicket mentions in a letter to his sister that her "suggestion...that a tea set would be a handy place to hide anything important and small...has turned out to be correct." A sugar bowl is one of the parts of a tea set. Later in the book, Violet Baudelaire notes that a tea set used by Count Olaf and Esmé Squalor is missing an item, implied to be a sugar bowl when Violet later lies that she and her siblings know the sugar bowl's whereabouts. The High Court judges (Count Olaf's bosses) searched the destroyed V.F.D. office after the fire they set to find the sugar bowl but did not find it, the bowl having been thrown out the window before the fire.
It is also mentioned in The Dismal Dinner that a sugar bowl was passed around at the Baudelaire parents' fourth-to-last dinner party, but it is not explicitly stated whether this is the same sugar bowl that was stolen from Esmé.
In The Unauthorized Autobiography, a letter to Lemony Snicket from the Vineyard of Fragrant Drapes (making use of Sebald Code in the note) mentions that "all the sugar bowls will be in place". Later, a similar letter can be found to Jerome Squalor about his marriage to Esmé. The latter letter also states that they were "unable to provide the sugar bowls [his] fiancé requested in a separate letter."
At some point prior to The Slippery Slope, the sugar bowl was taken to the V.F.D. headquarters in the Mortmain Mountains. The man with a beard but no hair and the woman with hair but no beard burnt down the headquarters but were unable to recover the sugar bowl; Lemony Snicket states in the narration that a brave volunteer threw the bowl out the window into the Stricken Stream, knowing it would be swept away and be saved from the villains.
In The Grim Grotto, Klaus Baudelaire and Captain Widdershins believed it to have washed into the Gorgonian Grotto, but when the grotto was explored, the bowl was not there; the narration implies that the bowl had been removed quite sometime before. It is here that the Baudelaires are told that the sugar bowl itself is not important; it's the contents of the bowl that matters.
In The Penultimate Peril, the sugar bowl was brought to the Hotel Denouement by V.F.D. crows. The villains' plan was to capture it by harpooning the crows, but due to the actions of Dewey Denouement, a plan was put in place to prevent the villains from securing it. The volunteers and villains originally thought it had fallen into the laundry room, but the Baudelaires later conclude that the sugar bowl had fallen into the pond. However, in a twist, Snicket reveals that the bowl was retrieved from the pond and carried away by taxi shortly before the destruction of the hotel and that this taxi driver was possibly himself, implying that Lemony currently has the sugar bowl.
Beatrice attended a tea party held by Esmé when the sugar bowl was taken from her, and Esmé may have then mistakenly deduced that Beatrice was the thief, or Beatrice colluded with Lemony to steal it together. This may be the crime that Lemony Snicket and Beatrice committed together before her death, as mentioned in 13 Shocking Secrets You'll Wish You Never Knew About Lemony Snicket. However, this crime is more commonly suspected to be the murder of Count Olaf's parents. Esmé's house on 667 Dark Avenue had a secret passageway connected to the Baudelaire Mansion, so it is plausible that Esmé used it to burn down the property as vengeance toward Beatrice for stealing from her.
There are many clues and hints about the sugar bowl and what it is, but Lemony Snicket does not reveal its secret at all in the book series, leaving an element of suspense for the readers. Although it is revealed in the Netflix Series that it contains a horseradish sugar hybrid, that can be used to cure the Medusoid Mycelium.
Theories Prior to The Release of The End (Episode)
Lemony Snicket: The Unauthorized Autobiography's index entry for the sugar bowl redirects the reader to the entries for 'hiding places' and Lena Pukalie's book I Lost Something at the Movies, a reference to real-life film critic Pauline Kael's I Lost It at the Movies; the link between the latter and the sugar bowl is not explained. However, Pauline Kael has said the word 'it' refers to "so many kinds of innocence" -- Lemony could be referring to an item that proves or embodies innocence.
- In multiple Q&A’s Daniel Handler has done around America, when asked what is inside of the Sugar Bowl, he replied by saying “What is usually in a sugar bowl.”. This supports Netflix's version, where sugar is, in fact, in the sugar bowl.
- The Slippery Slope indicates that the sugar bowl contains something that proves Lemony Snicket innocent of arsons committed by Count Olaf; The Penultimate Peril implies that Lemony Snicket has gained possession of the bowl. If this is the case, Snicket may have gone on to use the sugar bowl to clear his name; The Beatrice Letters reinforces this by the time its later segments take place, Snicket is apparently able to publicly rent an office and have mail delivered there, something he would be unable to do as a wanted fugitive.
- Esmé Squalor, when confronting the Baudelaires, Dewey Denouement, and their associates in The Penultimate Peril , emphasized the difficulty of finding a container that could hold the sugar bowl's contents safely, securely, and attractively, and stated many lives were lost in the quest to find it; she also states that it means very much to the Baudelaires and the Snickets. However, it is unclear where she is referring to the sugar bowl and where to its contents.
- There is also another possible use for the sugar bowl: it could contain the figurine mentioned in The Carnivorous Carnival since it was said to contain "vital evidence" and was relatively small.  If this theory is true, then the figurine was probably placed inside the sugar bowl as it wound down the Stricken Stream and taken away, which would be the reason that the Baudelaires didn't find it in the Gorgonian Grotto. One such theory is that the figurine is the statue of the Bombinating Beast from All the Wrong Questions.
- The sugar bowl could also contain something of great power, perhaps even greater than the Medusoid Mycelium. This is because Dewey said that Count Olaf wouldn't dare use the Mycelium if he (Dewey) had the sugar bowl. This might imply that Dewey could use the contents to retaliate, either because it contains some sort of weapon or if it contains evidence that could be used to convict Olaf of a crime, prove Lemony Snicket's innocence or both.
- The Sugar Bowl also may contain horseradish, the only cure to the Medusoid Mycelium (or wasabi, which is a culinary equivalent). Proof of this is in The End , in the commonplace book "A Series of Unfortunate Events":
|“||Ishmael's fear mongering has stopped work on the passageway, even though we have a plethora of horseradish in case of any emergency. We're attempting a botanical hybrid through the tuberous canopy, which should bring safely to fruition despite its dangers to our associates in utero. Of course, in case we are banished, Beatrice is hiding a small amount in a vess--||”|
- The "vess" part can be assumed to be Vessel For Disaccharides.  Whether this is a reference to the same sugar bowl that was stolen from Esmé Squalor, or simply evidence that the use of sugar bowls became common in V.F.D. to provide storage of sensitive items, is not known.
- The Sugar Bowl could also be empty (but believed to have contained something a long time ago) and is now merely a figure of power.
- There is a theory which states that V.F.D hid microphones in Sugar Bowls to record conversations (once such instance appeared in Lemony Snicket: An Unauthorised Autobiography with Mr. Poe). The Sugar Bowl could contain a highly important one, perhaps something that would prove Lemony's innocence.
- One theory is that the sugar bowl may contain the poison darts Beatrice used to kill Olaf's parents
- One theory is that the sugar bowl is merely a MacGuffin, a plot device whose contents of it are actually completely irrelevant and whose function is simply to be a much sought-after object that motivates characters and drives the story along.
The sugar bowl appears throughout the TV series:
- In "The Bad Beginning: Part Two," Count Olaf wonders aloud about where the sugar bowl is. This is the first time it is mentioned.
- It is revealed that it was at Heimlich Hospital before the hospital burns down. Kit Snicket rescued it just in time.
- Kit dives into a hole in a stream in the Mortmain Mountains. It floats down the Stricken Stream and ends up washed in the Gorgonian Grotto.
- Quigley Quagmire finds it at the grotto. He gives it to a V.F.D. crow.
- The Sugar Bowl is dropped into the vent at Hotel Denouement. Dewey Denouement knew where the vent led, but he died before he told the Baudelaires.
- It is later seen in Dewey Denouement's Underwater Library suggesting that the laundry chute brought it there.
- In "The End," Kit Snicket reveals that the Sugar Bowl contains a sugar capable of immunising its consumers from the Medusoid Mycelium. A small amount was stored in the Sugar Bowl by the Baudelaire parents on their escape from the Island.
- There is a VFD quote saying, Tea should be as bitter as wormwood, and as sharp as a two-edged sword." This is a paraphrase of Proverbs 5:3-4 -- "Though the lips of the immoral woman drip honey and her speech is smoother than oil / In the end she is bitter as wormwood, sharp as a two-edged sword."
- Daniel Handler comments, "The mystery of the Sugar Bowl is clear enough that about a reader a year writes me and has figured it out, and that fills me with pleasure. That makes me think it's not too obscure. If no one ever wrote me about it I would think, "Oh, I didn't do it enough." But because one person a year who will write me and say, "I figured it out." The whole answer of the Sugar Bowl is solvable." This comment was made in an interview Handler gave after the release of season 1 of the Netflix series, while he was writing season 2. At this point in time, he did not seem to think the series would change the contents of the sugar bowl from what he had intended in the books.