Water: the tap water is safe to drink and tasty. It is ok to order tap water in restaurants. Usually "tap water" was understood. We never experienced any hesitation from a waiter to bring tap instead of bottled water. I think the locals are quite proud of their water.
Liquor
Rakija, mistletoe liquor, and many other alcohols are as popular in Istria as they are in Zagreb. All the tourist places eagerly give free samples. We found that the prices for liquor were cheaper in the airport duty-free shops of Zagreb airport than they were in tourist shops. In grocery stores, they have good prices as well, but only in large sizes.
Restaurants
Batelina (Knobo Batelina or Restaurant Batelina) (ÄŒimulje 25, 52100, Banjole. Phone 052 573 767) If you are anywhere in Istria, this is your destination restaurant. 90% of their tables are booked in advance so do make reservations; they recommend at least a week before. They are closed in August because the fish are too far out to sea for their fishing boat, and closed 3 weeks in January because "all the locals are skiing." It has recently been reviewed by Michelin and so is getting more attention. Banjole is a small town in the middle of nowhere (about 20 minutes south of Pula), but if you are in Istria everything is a pretty quick drive.
The owner and chef of this restaurant goes out in his boat each day to fish, and the restaurant offers what he catches each night. But it isn't just about the catch-of-the-day freshness. Preparations of the fish are excellent and the service is gracious. If you agree to appetizers you are treated to many small dishes of various fishes: smoked, pickled, and cooked. All were excellent, but our favorite was the smoked sea bass. (This was $12 for 2 people). Then we were asked if we'd like to hear about pastas or move directly to the main fishes. We asked to hear about both and got excited by the pastas. All this is made in-house. We had parsnip ravioli with tuna chunks in sauce and a scampi ravioli. Excellent. For the main fishes, the waiter showed us the catch--monkfish, squid and others, and listed a few others not on the tray. We had scallops which are charged by the piece (4.50 Euros each). We also had their house red wine. When we asked for 2 glasses the waiter said "I'll bring you a 1/4 bottle which is about the same." This was a more economical way to order. He also cautioned us about filling up on bread. We had one dessert, a coffee concoction that was like a cross between pudding and tiramisu and it was excellent.
The entire dinner was only $45 per person. Our waiter said many foreigners have remarked that the price is so reasonable, and she responds that they must keep prices low because they are a local restaurant and if the locals are priced out, they can't stay in business. We have very fond memories of the food, the service, and the quaint table next to a fire--just right in late October.
La Fondiara Restaurant in Rovinj (Iza Kasarne 14, 52210, Rovinj, Croatia): We stayed in Rovinj and saw this quaint restaurant on our initial walk about the town. The food was good and service friendly. We had tuna tartare as a starter, and a simple sea bass soup and very rich and delicious mushroom risotto for our mains. The fire was lit and the interior of this restaurant is super cute. These three dishes were a total of 38 Euros.
They are open 8 months, from March to approximately the end of October. We got in just before the close of their season, which was the Saturday after All Saints Day.
Truffles: check out our page about our truffle hunt and dining pleasures. The producer we chose had excellent food prepared with their truffle products. You can see similar products sold everywhere, but you don't get to try everything as you do at the producer's home.
Other foods: there are many gelato stores, and many have vegan options. We had decent food throughout Istria, though no others which particularly stood out to recommend.