Dveila Keilis (Eruvin 27b)

The gemara says that had the pasuk about maaser sheni only said shechar we would have thought that it was coming to include dveila keilis (intoxicating dates from Keilis). We already know the klal, prat u'klal includes all food so why would would we have thought the extra limud includes these dates? Why wouldn't they be included?

Tosafos (in the middle of d"h hava) suggests that we're talking about watered down dates. It's more likely to be included than temed because the water is really mixed in but you still might have thought that it wasn't included like other foods. The Ritva has another answer. He says that these dates are inferior and aren't good for you so they're not normally eaten. You might have thought that they weren't considered like other foods and you couldn't redeem your maaser sheni onto them. (The Ritva has a a long, thorough explanation of our whole gemara. I didn't go through the whole thing but it did seem good.)