In recent years there has emerged a dispute whether Hamotzi or Mezonot should be recited on one slice of pizza. We will present the background to this issue in the Gemara, Rishonim, and Acharonim. Then we will explain the two sides of the contemporary debate on this issue.
The Gemara (Brachot 42a) records the rule that one should recite Mezonot on Pat Habaah B'Kisnin as long as he does not establish a meal on it. If, however, he does establish a meal on Pat Habaah B'Kisnin, then he must recite Hamotzi. The Rishonim debate two major points about this Gemara. First, what exactly is Pat Habaah B'Kisnin? Second, how do we determine that one has "established a meal" on Pat Habaah B'Kisnin?
The Definition of Pat Habaah B'Kisnin
The first opinion regarding the definition of Pat Habaah B'Kisnin is the view of Rav Hai Gaon, who believes that it is crackers. Rabbeinu Chananel and the Aruch define it as "bread that is baked with a pocket full of honey, sugar, nuts, or spices." This is what we call pie. The Rambam (Hilchot Brachot 3:9) defines it as "dough that has honey, oil, milk, or spices mixed in it." This is what we call cake. Rama (O.C.168:7) explains that only when a considerable amount of spices or honey is added is it called cake.
Mishna Berura (168:33) explains that it is a "considerable amount" only when the spices or honey is a dominant taste. Only then is it defined as cake and not as bread. Parenthetically, it should be noted that this is one of the reasons that Rav Aharon Lichtenstein, Rav Hershel Schachter, Rav Mordechai Willig, and virtually every Rav that this author is acquainted with believes that Hamotzi should be recited over "Mezonot Bread." Even though apple juice is added to the dough in the baking of "Mezonot Bread," its Beracha is Hamotzi because the taste of the apple juice is hardly noticeable. Moreover, people treat "Mezonot Bread" exactly as bread and thus it cannot qualify as Pat Habaah B'Kisnin that by definition is a snack-type food.
Interestingly, the Shulchan Aruch (168:7) rules in accordance with all three views. Indeed, many Acharonim query as to why the Shulchan Aruch decided to do so. One suggestion is that the Rishonim do not disagree but are simply offering different examples of Pat Habaah B'Kisnin. Thus all agree that pie, cake, and crackers are considered Pat Habaah B'Kisnin (see Biur Halacha s.v. V'halacha and Rav Mordechai Willig's Am Mordechai page 100).
The Shulchan Aruch (168:17), however, writes that baked dough filled with meat, fish, or cheese requires the Beracha of Hamotzi. The Mishna Berura (168:94) explains that Hamotzi is required even if he did not "establish a meal" on these foods. This is because these are "meal-type foods" and not snacks, in contradistinction to pie, cake, and crackers. This rule is not absolute, as the Mishna Berura rules that "franks in a blanket" are snacks, and Mezonot is recited on them (unless one establishes a meal on them).
Definition of Establishment of a Meal
Next we will examine the issue of when one is considered to have established a meal on Pat Habaah B'kisnin. The Rishonim argue if establishing a meal is determined by each individual according to his particular standard or by what most people consider to constitute a meal. The Rosh (Brachot 6:30) cites the Raavad, who believes that each individual determines what is considered to be a meal by his own individual standard, and the Rashba (commenting to Brachot 42a), who disagrees and states that it is determined by what most people consider a meal. The Rosh sides with the Rashba. The Shulchan Aruch (Orach Chaim 168:6) rules in accordance with the opinion of the Rashba and the Rosh. Thus, one must recite Hamotzi if he has eaten an amount of Pat Habaah B'Kisnin that most people consider a meal, even though by his personal standards he is merely consuming a snack (also see Mishna Berura 168:24). It should be noted that the Biur Halacha (s.v. Af Al Pi) asserts that the "objective standard" varies from group to group. He specifically mentions a distinction between young and old people. Thus, if an older individual plans to eat an amount of Pat Habaah B'Kisnin that most older people consider to constitute a meal, he must recite Hamotzi even though a younger person would view that amount of food as merely a snack. Rav Danny Wolf of Yeshivat Har Etzion (Daf Kesher volume 6) suggests that a distinction can be made between men and women in this matter, as men generally eat more than women.
It should be noted that one need not eat an entire meal of Pat Habaah B'Kisnin in order to establish a meal. One must recite Hamotzi when he plans to eat some Pat Habaah B'Kisnin along with enough food to establish a meal (see Mishna Berura 168:24, Teshuvot Igrot Moshe O.C. 1:56, and the interesting opinion of Rav Yaakov Kaminetzsky cited in The Halachos of Brachos p. 261 note 6.1). Thus, for example, if one eats potato pie along with a full dinner, he must wash and recite Hamotzi and Birkat Hamazon.
Contemporary Rabbinical Authorities
The debate whether the Beracha for one slice of pizza is Mezonot or Hamotzi hinges on the question if pizza is viewed as "meal food" or "snack food." Many people recite Mezonot on one slice of pizza based on Rav Moshe Feinstein's reported ruling that pizza is Pat Habaah B'Kisnin. Rav Moshe is reported to have asserted that pizza is a snack-type food and that one does not establish a meal when he eats only one slice of pizza.
Other Poskim disagree. Rav Mordechai Willig (Am Mordechai page 99) rules that Hamotzi should be recited even on one slice of pizza because most often pizza is consumed on the context of a meal and not as a snack. Rav Yisrael Belsky (Mesora 1:40) agrees with Rav Willig. Rav Zalman Nechemia Goldberg and Rav Hershel Schachter also told this author that Hamotzi is the appropriate Beracha even for one slice of pizza. Rav Willig, however, notes that pretzels are considered Pat Habaah B'Kisnin because they are commonly eaten as a snack. One should consult his Rav regarding which of these opinions should be followed.