Maran (author of the Shulhan Aruch), in his work Bet Yosef (Orah Haim 286), records the requirement to taste all foods that one prepares for Shabbat on Ereb Shabbat. Some have suggested an allusion to this Halacha from the passage in the Shabbat Musaf prayer, "To’ameha Haim Zachu" ("Those who taste of it [Shabbat] earn life"), which may be read to mean, "Those who taste of its food earn life." This passage might allude to the fact that those who observe this Halacha and taste the Shabbat food before Shabbat are rewarded with long life.
What is the reason for this requirement? Why is it important to taste the Shabbat food before the onset of Shabbat?
The most basic explanation is that this Halacha helps ensure that the food will be tasty for Shabbat, in the interest of avoiding discontent and tension in the home. On Shabbat, the home must be imbued with an aura of "Shalom Bayit" – peace and serenity – and to that end, one should ensure before Shabbat that the food is prepared properly, so that the family will not be disappointed during the meals. (This is also one of the reasons given for the obligation of candle lighting, which ensures the presence of light in the home, bringing a sense of calm and serenity.)
The Arizal (Rabbi Yishak Luria, 1534-1572), as cited in Sha’ar Ha’kavanot, suggested a deeper reason. Royal palaces often hired professional "tasters" assigned the job of tasting the food before it was served to the king. A king’s special royal stature demanded that he received his meals only after the food was tasted and determined worthy of being served to a king. As Shabbat is the "queen" that enters our homes, we must first taste the food before it is served, just as tasters must taste the food before it is served to a king.
The Halachic authorities address the question of whether one recites a Beracha before tasting the food. Although Halacha normally requires reciting a Beracha before partaking of even a small amount of food or drink, in this instance, where a person ingests the food only for tasting purposes, perhaps no Beracha is warranted.
Indeed, the Shulhan Aruch (Orah Haim 210) rules that if a person tastes less than a Rebi’it (approx. 3 oz.) of a liquid or a Ke’zayit (approx. 30 grams) of a solid food, he does not recite a Beracha. Since he ingests the liquid or food only for the purpose of tasting, he does not recite a Beracha unless he partakes of a significant amount.
However, given the difference of opinion that exists in this regard, Hacham Ovadia Yosef writes in his Hazon Ovadia (Laws of Shabbat, p. 21) that one should preferably taste the food with the intent of eating or drinking, and not merely tasting. Meaning, a person should have in mind that he not only tastes the food for the purpose of determining its quality, but also eats or drinks for the purpose of deriving benefit from the food. In this way, he is required to recite a Beracha according to all views, thereby avoiding the debate surrounding this issue.
It should be noted that Hacham Ovadia extends this Halacha to Ereb Yom Tob, as well. One should make a point of tasting not only the food prepared for Shabbat, but also the food prepared for Yom Tob.
Another question arises as to whether one may taste meat dishes that one prepares on Ereb Shabbat Hazon, meaning, the Friday immediately preceding Tisha B’Ab, when Halacha generally forbids partaking of meat. Do we make an exception to this Halacha in order to enable one to taste the Shabbat food, or must one refrain from tasting meat dishes on Ereb Shabbat Hazon? (On the Shabbat itself, of course, it is permissible to eat meat.)
Hacham Ovadia rules that it is permissible to partake of meat dishes after Hasot (midday as defined by Halacha) on Ereb Shabbat Hazon, as this is done for the honor of Shabbat. However, he adds, one must ensure to only taste the food as is necessary to determine its quality, and not to sit down to eat significant portions of the Shabbat food. Many people enjoy eating portions of the Shabbat food on Ereb Shabbat. On Ereb Shabbat Hazon, one may not partake of the meat dishes prepared for Shabbat, except to taste them to determine their quality, and eat less than a Kezayit and less than a Rebeit.
Summary: On Ereb Shabbat, one should taste all the food prepared for Shabbat in order to ensure that it was prepared properly. Preferably, one should have in mind to eat the food for enjoyment, and not merely for tasting, so that he will be required to recite a Beracha according to all opinions, thereby avoiding the Halachic controversy surrounding this issue. It is permissible to taste meat dishes that one prepares on Ereb Shabbat Hazon (the Friday during the nine days) after midday, but he must ensure not to eat any more than what is required to determine the food’s quality (less the a Kezayit and Rebeit.)
