Micha Moka, who is fairly new to observant Judaism, presents the following question:
“This is the first time that I am purchasing my own esrog. I have been told that many esrogim may not be kosher because they, or their antecedents, were grafted onto other citrus trees. But, I don’t understand what the problem is. When you graft a branch of one species onto another tree, the fruit that grows should be identical to any other fruit of the branch species.”
In Parshas Emor, the Torah teaches, And on the first day you shall take for yourselves the fruit of a beautiful tree… and you shall rejoice with it before Hashem your G-d seven days. The Hebrew term used to describe the fruit is pri eitz hadar. The word hadar is used many times in Tanach to refer to the glory of Hashem Himself. The Ramban explains the word esrog to be the Aramaic translation of the Hebrew word hadar, both words meaning desired or beautiful. (The Modern Hebrew use of the word hadar to mean citrus has no basis in traditional Hebrew, but was borrowed from the pasuk. Unfortunately, as a result of this modern convention, Israelis often misunderstand the pasuk.)
How do we know that it is an esrog?
The Written Torah does not provide any more details with which to identify this fruit, but the Oral Torah’s mesorah from Sinai is that the Torah means the species that we call an esrog, which is called Citrus medica in scientific jargon, based on its extensive medical value. Certainly, the oral mesorah itself provides sufficient basis for us to know which species is pri eitz hadar, but in addition, Chazal infer hermeneutically from the pasuk three features that are unique to the esrog.
Feature #1: Its Bark is as Good as its Bite
(1) The bark tastes like the fruit. This means that the natural oils, flavinoids, and other chemical components that impart the unique fragrance and flavor of an esrog exist in sufficient quantity in the bark such that it bears the smell and “taste” of the fruit.
Some early authorities note that this factor seems common to all citrus and not unique to the esrog. Other citrus fruits also bear their unique components in their leaves, peels, and bark such that one can identify the leaf or bark of a lemon or orange tree by its aroma.
However, the Kapos Temarim explains that an esrog is unique in that the taste of “its fruit and bark are equal.” The esrog is unique in that it has little or no pulp, unlike other edible citrus fruits. Therefore, the main part of the esrog is its “rind,” which bears a much closer flavor to its bark than does the pulp of any other fruit.
Feature #2: The Fruit Remains on the Tree
(2) Much of this year’s unpicked crop of esrogim will remain on the tree until the next year’s crop is growing, and sometimes, this fruit remains on the tree for as long as two or more years. As a general rule, non-citrus trees drop their fruit at the end of the season. Most other citrus also drop their fruit when overripe, although some individual fruits still remain on the tree. Esrog does indeed remain longer on the tree than any other citrus, and although some fruit falls off, an impressive percentage remains on the tree, sometimes for as long as two years.
Feature #3: Water, Water Everywhere
(3) An esrog requires year-round irrigation to produce sizable fruit. At the time I am writing this article, I have been unable to discover any unique feature of esrogim differentiating them from other types of citrus, all of which require year-round irrigation to produce large fruit.
Notwithstanding this description, a fruit still may have all these three features and still not be considered an esrog according to most authorities. We will soon see why.
Common production of citrus is to graft the branches of the desired variety of fruit onto rootstocks that allow a greater yield, are more resistant to disease, and provide other commercial value. It is prohibited for a Jew to graft one species onto another stock, and it is a dispute among halachic authorities whether a gentile may or may not. (A number of years ago, I wrote an article on the subject of whether a gentile may graft and/or own grafted fruit trees.) Most authorities understand that different varieties of citrus are halachically considered different species concerning the prohibition of grafting fruits (however, see Chazon Ish who conjectures whether the similar characteristics of citrus might allow them to be considered one species, in regard to the prohibition of grafting.)
May one use a Grafted Esrog?
When one grafts the fruit of one species onto the rootstock of another, the fruit will grow according to the species of the scion branch, an observable phenomenon noted already by Rashi. Our question: is the fruit of an esrog branch grafted onto a lemon stock halachically an esrog? Are there any other halachic concerns because it grew on a non-esrog stock?
Graft in Sixteenth Century Poland
The earliest responsum on the subject that I discovered is authored by the Rama, who probably never saw an esrog tree in his life. Citrus trees are not generally frost-hardy, and therefore grow in warmer areas than Poland, where the Rama lived his entire life. When reading his responsum on the matter, we should bear in mind the difficulty of obtaining esrogim for Sukkos in his place and era.
Rama writes very tersely that the fruit of a graft is not called an esrog, nor is it called the fruit of a hadar tree.
The Rama notes that although there were earlier scholars who recited a beracha on grafted esrogim when they had no others available, we should not rely on this when we have access to non-grafted esrogim. (For the balance of this chapter, when I refer to “grafted esrogim,” I mean esrogim grafted onto a rootstock of a non-esrog species. All authorities allow use of a fruit grown on an esrog branch grafted onto another esrog tree.)
A Ransomed Esrog
A contemporary and second cousin of the Rama, Rav Shmuel Yehuda Katzenellenbogen, the rav of Venice from 5326- 5357 (1566-1597), was asked whether one may use an esrog grafted onto a lemon tree, and responded that every child knows that these esrogim may not be used. Rav Katzenellenbogen writes that he heard from his father, Rav Meir Katzenellenbogen, the famed Maharam Padua (named for the city he served as rav for many decades), a fascinating anecdote:
One year, the entire community of Padua was able to acquire only one non-grafted esrog for Sukkos, which had to service all the different congregations of the city, although grafted esrog trees were apparently very popular decorative trees there and were readily available in the houses of the gentry. When the esrog was sent from one congregation to another, it was stolen by rowdy gentile students, who held the esrog for ransom. The community needed to redeem the kidnapped esrog for a considerable amount of money, which they did in order to fulfill the mitzvah, notwithstanding the fact that they had ready access to a large supply of very inexpensive, locally grown, grafted esrogim. Thus, the community purchased a non-grafted esrog twice in order to fulfill the mitzvah!
(Two curious side points about Rav Shmuel Yehuda Katzenellenbogen: the first is that we do not have an extant edition of his responsa. This particular undated responsum is published in the Shu’t Rama. The second is that he is often called the Mahari Padua, meaning Rav Yehudah, who had been born in Padua, to distinguish him from his father.)
Graft in the Holy Land!
A third responsum from the same era deals with the identical issue in Eretz Yisrael. Prior to Sukkos of 5346 (1585), in Tzfas, the Alshich was asked about using a grafted esrog. He relates that one local rav wanted to permit use of this esrog, notwithstanding the fact that all the other authorities prohibited use of grafted esrogim for Sukkos. The rabbonim of Tzfas were concerned that the lenient opinion of this individual rabbi would be accepted against the consensus. This rav contended that the nourishment drawn from the lemon stock was already nullified in the esrog branch, and the fruit is therefore considered to be completely esrog.
In his discussion on the subject, the Alshich demonstrates, from the laws of orlah, that we consider the branch to be nullified to the stock and not the other way around, since a young branch grafted onto a stock more than three years old is not subject to the laws of orlah,whereas an older branch grafted onto a young stock is.
Furthermore, the Alshich contends that even if the esrog was not nullified to the lemon as the laws of orlah imply, the resultant fruit should be considered a blend of both species and not purely esrog. Therefore, even if the fruit is considered an esrog, it is an incomplete esrog, and therefore invalid, because it has some lemon content.
A Different Graft Problem
A disciple of the Rama, Rav Mordechai Yaffe, often called the Levush because of the titles of his published works, contended that a grafted esrog may not be used for Sukkos for a different reason: since the Torah disapproves of grafting, one may not fulfill mitzvos with grafted products, just as a crossbred animal may not be used for a korban. (By the way, both a fruit grafted from two kosher species and an animal crossbred from two kosher species are kosher – for eating purposes.)
Not all authorities agreed with the Levush in this argument. The Taz questions whether this principle of the Levush is accurate, rallying sources that the fact that something sinful had previously been performed with an item does not automatically invalidate it for mitzvah use.
The Taz still concludes that one should not use a grafted esrog because of a different reason, one of those that the Alshich had mentioned: that a grafted esrog should be considered incomplete because of the admixture of other species. However, the Taz notes that a halachic difference results between his reason and that of the Levush, since the halacha is that a damaged or incomplete esrog (called an esrog chaseir) may be used to fulfill the mitzvah after the first day of Sukkos. Since, in his opinion, the shortcoming of a grafted esrog is its incompleteness as an esrog, one could use it after the first day of Sukkos. The Taz then notes that perhaps an esrog from a grafted branch or tree is worse than an incomplete esrog, in that it is considered qualitatively to be only partly esrog, and that one should avoid using it under any circumstances, so that people not err and think that it is a kosher esrog.
Can one identify a Grafted Esrog?
The vast majority of halachic authorities concluded that one does not fulfill the mitzvah with a grafted esrog. A later debate focused on whether the fruit of a tree planted from the seed of a grafted esrog is also invalid, with the Beis Efrayim contending that these esrogim are kosher, and other authorities disputing its kashrus. This led to a new debate. If the tree grown from a grafted esrog is no longer considered an esrog tree (for the purposes of fulfilling the mitzvah), how can one ever know that the esrog he wants to use is kosher?
This led to a dispute in the early nineteenth century, which I will refer to as the machlokes between those accepting esrogim on the basis of simanim, versus those accepting them on the basis of mesorah.
The Beis Efrayim ruled that one may use an esrog if it has the physical characteristics, the simanim, of a non-grafted esrog. His contemporary, the Chasam Sofer, disputed this, and ruled that just as we no longer rely on simanim to decide which birds we treat as kosher, but rely exclusively on a mesorah to determine the kashrus of a bird, so too, we can use esrogim only from places where we have a mesorah that they are kosher.
What are the characteristics that distinguish between a grafted and non-grafted esrog?
In the above quoted responsum of the Mahari Padua, he writes that one can identify whether an esrog was grown on a branch grafted onto another tree by three characteristics:
(1) Smooth Skinned
The skin of a grafted esrog is smooth, more like a lemon, whereas a pure esrog has a bumpy surface.
(2) Outward Stemmed
The stem (the ukatz) of a grafted esrog looks like a lemon’s stem, which sticks up from the bottom of the lemon, instead of being imbedded inward like that of an esrog.
(3) Fruity and Thin Skinned
A grafted esrog has a lot of edible fruit and juice in it and a thin peel, whereas a pure esrog has a thick peel and little juicy flesh.
(4) Disoriented Seeds
Some later authorities noted another distinction between a regular esrog and a grafted one. In a regular esrog, the seeds grow in the same direction as the length of the fruit, whereas grafted esrogim often have their seeds growing like a lemon’s, in the same direction as the width of the fruit. Other authorities disputed whether this demonstrates that the esrog has been grafted.
Does Grafting Affect the Fruit?
Micha had noted correctly that when you graft a branch of one species onto the stock of another, the fruit that grows is from the scion branch and not from the species of the stock. However, for reasons not fully understood by contemporary scientists, there are significant modifications to the fruit that develop when it does not grow on its own natural stock. From a commercial perspective, these modifications are desirable, for they make the fruit more disease resistant and provide other qualities. However, in the case of an esrog, this creates halachic concerns.
Let us note that today there are several different types of esrog that have mesorah that they are not grafted. Aside from the conventional European or Israeli esrog that most of us are used to, there are also the Moroccan esrog and the Yemenite esrog, notwithstanding the fact that on both the inside and outside these esrogim are definitely distinguishable from the European or Israeli esrogim that Ashkenazim are accustomed to.
Research teams from the University of Catania, Italy, and Hebrew University jointly studied twelve varieties of esrog, including the standard Moroccan, Yemenite, Italian, Chazon Ish, and other varieties, to see whether they were indeed consistently one species, or whether the DNA indicated that they were of different species and origins.
The study concluded that all twelve varieties are in fact esrogim, and indeed are genetically separable from other citrus fruits, including the lemon, which appears most similar to the esrog.
To quote the study: “The results obtained are very clear and might be regarded as somewhat surprising. Notwithstanding diverse geographical origin and the considerable morphological variation, especially in fruit size and shape, presence of pulp and persistence of style, all the citron types examined revealed a high degree of similarity. There was no sign of introgression of lemon or other citrus genomes into any of the citrons examined”.
We should note, that even though genetically all the varieties tested are indeed esrogim, we cannot rely on genetic testing to prove the authenticity of a particular esrog, since, if it was grafted onto non-esrog stock, it would be invalid for use for Sukkos, according to most authorities. In addition, the decision as to whether one may plant his fruit or stock and use future generations of this esrog is dependent on the above-quoted dispute between those who follow mesorah and those who follow simanim.
Two generations ago, many, if not most, esrog trees in Eretz Yisrael were grafted onto the stock of a variety of orange tree called the chushchash, which bears a fruit that is non-edible raw. The farmers of the era claim to being told that since the chushchash is not edible, using it as a stock for the esrog is permitted and would not invalidate the fruit, a position that is difficult to sustain and has been rejected by subsequent authorities. A result of this is that the Chazon Ish, and many other authorities had difficulty finding esrogim in Eretz Yisrael, and the Chazon Ish chose the tree for his esrog very carefully. One year he entrusted a seed from that esrog to Rav Michel Yehudah Lefkowitz zt”l to plant. Rav Michel Yehudah protested that he had no experience in horticulture and esrogim require considerable knowledge to grow properly. The Chazon Ish told him, “Just plant this seed and make sure to water it regularly, and you will have plenty of esrogim to sell.” Rav Michel Yehudah did as he was told, surprised at the instructions, notwithstanding his lack of experience. His tree grew, and for over seventy years produced gorgeous esrogim without any efforts on his part. This itself can be considered a miracle, for two different reasons: (1) Esrogim do not usually grow nicely on the tree without considerable work. (2) Esrog trees do not live this long.
Many of the “Chazon Ish” pardesim now so popular were begun with trimmings of branches taken from Rav Michel Yehudah’s tree.
This past Nissan, this esrog tree was indeed still covered with beautiful blossoms, indicative of another beautiful crop. The tree was in excellent shape, notwithstanding that the Chazon Ish is gone almost sixty years and the tree is over seventy years old. Its regular customers were looking forward to selecting esrogim from this ancient tree.
As our readers know, Rav Michel Yehudah passed away a few months ago at the age of 97. Although the same people are still watering the tree, the tree began to wither and completely stopped producing fruit in midseason, and is suddenly showing signs of severe aging.
Certainly a miraculous sign, but the phenomenon can be readily explained. When Rav Michel Yehudah protested that he knew nothing of esrog horticulture, the Chazon Ish promised him that he need only water the tree and it would produce fruit. As long as Rav Michel Yehudah was alive, the beracha of the Chazon Ish was fulfilled, and we have a rule, tzadik gozeir, Hakadosh Baruch Hu mekayeim, If a righteous person decrees something, Hashem fulfills it. As long as Rav Michel Yehudah was alive, the beracha of the Chazon Ish had to be fulfilled, despite the long odds against it. Once Rav Michel Yehudah passed on, the decree of the Chazon Ish no longer had to be fulfilled, and the tree no longer lived.
The author acknowledges the assistance of Dr. Joshua Klein, senior scientist at the Volcani Center, Israel Ministry of Agriculture for technical information in this article.
 Vayikra 23:40
 See, for example, Tehillim 96:6; 104:1
 Vayikra 23:40
 Rambam, introduction to Peirush Hamishnayos
 Sukkah 35a
 Shu’t Rama #117
 Sukkah 35a
 Quoted by Shu’t Chasam Sofer, Orach Chayim #207
 Note that the Kappos Temarim, Sukkah 35a, explains the difference between esrog and other citrus slightly differently.
 For more information, see “May a Non-Jew Own a Nectarine Tree?”
 Kelayim 2:15; 3:7
 Sotah 43b
 Shu’t Rama #117
 Shu’t Bach #135; Mishnah Berurah 648:65
 Shu’t Maharam Alshich #110
 Orach Chayim 649:4
 One authority that permitted its use is the Shu’t Panim Meiros, Volume II #173.
 Shu’t Orach Chayim #56
 Bikkurei Yaakov 648:53
 Proceedings of the International Society of Citriculture, December, ’00
 See Moed Katan 16b