How is Kedem Light grape juice made and is there a question of “boser” (unripe grapes)?
Kedem lite grape juice has become indispensable for many seeking to lower sugar intake while partaking of Kiddush and the Arba Kosos. The secret to low-sugar grape juice is to use lower-sugar grapes. Kedem Light Grape Juice uses early harvest Concord grapes which are picked at about 11-13 Brix. (end-harvest concord grapes will reach 18 Brix). Some have questioned whether these grapes are "boser" (unripe grapes).
The beracha on boser is Ha'odama (not Ha'Eitz) and Sharei Teshuva writes that the beracha on juice made from boser grapes is Shehakol (not Ha'Gafen). However, the grapes in question are full sized and purple. They look the same as other ripened Concord grapes and taste less sweet and more tart than regular grapes. The Mishnah Berurah writes that once grapes have the appearance of ripened grapes, they are no longer boser. Furthermore, the Levush writes that boser refers to grapes that cannot be made into wine. This does not apply to these grapes, since they can be made into a wine albeit with lower alcohol level (about a 5-6%). To lower the sugar more, Kedem Light Grape juice is also diluted with about 33% water. Therefore, the Beracha on Light Grape Juice is Borei Pri Ha’Gafen. It is not recommended to add additional water to Lite grape juice.