May one purchase juice without a Hashgacha?
A. Freshly squeezed juice stands:
One may purchase juice at a fruit stand without a Hashgacha so long as the following conditions are met:
- One is not in Eretz Yisrael, and the fruits used have no reason to be assumed that they come from Eretz Yisrael.
- There are no powders or other additives without a Hashgacha placed into the juice and it is 100% pure juice, as witnessed by the Jewish buyer.
- There are no grapes added to the ingredients of the juice.
- Sugar may be added.
- The fruits used for the shake are not required to be checked for insects, or one checks the fruit prior to its use.
- The knife being used to cut the fruit has been washed.
- The machine used for the squeezing [both its blades and container] has been washed completely clean from any previous uses [which may have included grapes or grape juice or Chalav Akum milk].
- Lemons: One should not add lemons to the ingredients being that lemons are considered a Davar Charif and can absorb taste from the blades of the knife.
B. Bottled juices:
All processed juices, which refers to all juices that are factory made and packaged, even if they state 100% juice, must have a reliable Hashgacha in order to verify that non-Kosher ingredients have not been used in making the juice. The possible Kashrus issues involved with processed juices are:
- Chalav Akum: Perhaps the machine line used for the juice contained remnants of non-Kosher milk. Likewise, perhaps the juice was pasteurized [heated] in a container that is also used to heat non-Kosher milk. [It is common for juicing factories to make various beverages on different days of the week, including milk beverages.]
- Yayin Nesech: Perhaps the machine line used for the juice contained remnants of grape juice, which is Yayin Nesech. Likewise perhaps the juice was pasteurized [heated] in a container that is also used to heat grape juice. [It is common for juicing factories to make various beverages on different days of the week, including grape beverages.]
- Insects: If the fruit requires checking for bugs, then this must be verified prior to squeezing.
- Additives: Perhaps a non-Kosher additive, preservative, food coloring or some other sub-ingredient has been added to the drink. [Such additives do not legally prevent the writing of 100% pure juice if they are considered a mere trace ingredient.]
 The reason: Fruits of Eretz Yisrael must be verified to not contain an Arla prohibition, likewise both fruits and vegetables must be tithed prior to eating.
 The reason: As this enters one into an issue of Yayin Nesech, if the juice maker is a gentile or is not a Shomer Shabbos Jew.
 Sugar does not need a Hashgacha.
 It is forbidden to grind fruits that require checking with exception to specific circumstances in which this is allowed: See Michaber 84/14; Shach 84/39-40; Taz 84/19-20; Darkei Teshuvah 84/165-169; Kaf Hachaim 84/131-134
 See Michaber/Rama 96/4; Shach 96/20