Glad to hear that your MacBook is fine.
If beer got into the headphone jack and dried there you have a sticky situation. The headphone jack is difficult to clean and liquid damage is not covered under the ipad's warranty. If you bought AppleCare + when you bought the iPad, and your AppleCare+ is still in effect I would have an Apple technician examine your device. The cost for repair will be minimal. Make an appointment at an Apple Store to have your device examined by a technician. Or contact Apple Support. Be sure to back up your device before taking or sending it to Apple.
If you didn't purchase AppleCare + you might try a thin damp cloth on a toothpick to try an clean the headphone port. Also make sure the headphone jack itself is clean. Another option might be to insert and remove the headphone jack wiping it clean each time. Perhaps you can free up the little switch inside the port that turns off the volume to the iPad when headphones are used.