Recently, someone directed my attention to the International Standard Bible Encyclopaedia (ISBE), specifically the contents of its entry on wine related to the Hebrew word shekar. This was offered as evidence that shekar was not necessarily alcoholic.
Here is the relevant part of the ISBE entry Wine; Wine Press:
(7) שׁכר, shēkhār (22 times), translated “strong drink” in English Versions of the Bible. Shēkhār appears to mean “intoxicating drink” of any sort and in Num_28:7 is certainly simply “wine” (compare also its use in parallelism to “wine” in Isa_5:11, Isa_5:22, etc.). In certain passages (Lev_10:9; Num_6:3; 1Sa_1:15, etc.), however, it is distinguished from “wine,” and the meaning is not quite certain. But it would seem to mean “drink not made from grapes.” Of such only pomegranate wine is named in the Bible (Son_8:2), but a variety of such preparations (made from apples, quinces, dates, barley, etc.) were known to the ancients and must have been used in Palestine also. The translation “strong drink” is unfortunate, for it suggests “distilled liquor,” “brandy,” which is hardly in point. See DRINK, STRONG.
We notice that shekar “appears to mean ‘intoxicating drink’ of any sort.” Sometimes it simply means wine and sometimes it is distinct from wine, but it is always intoxicating.
When the text says “it would seem to mean ‘drink not made from grapes'”, the context of that statement still refers to intoxicating drink, thus the author identifies shekar as “[intoxicating] drink not made from grapes.”
The sole biblical example of pomegranate wine (not juice) is mentioned, and then the author states that “preparations” of other fruits and grains are know to have been used historically. The author did not say shekar might be apple juice, but that a preparation of apples (etc.) could be used to make shekar.
When examined carefully, this text does not leave room for shekar to be anything other than an alcoholic beverage.