Dog vs. coffee grinder (how to control barking)

You need to desensitize her to it. Basically, when you train, you start with broad sweeping gestures to make it very clear for your dog what you want. When they offer something close to the behavior, you reward them. Eventually, you ask for a better and better version, till it tightens up and you can achieve a complex action with a small cue.

That has happened spontaneously with your dog. It happens to most people with dogs. They train things that they don't consciously try to. Like how picking up a leash can cause a similar reaction to the one you describe. The leash is just a piece of string with a blob of metal on the end. However, they've come to associate that with going out. So your dog, whose breed tends to have high energy anyway, gets excited when something like your grinder, gives off a lot of excitement energy. The grinder makes noise, vibrates, and gives off pungent smells from whatever is being ground. It's natural that this is exciting; and just like training a cue for a behavior, she's come to recognize that just touching the grinder will lead to the excitement.

So you have to work on training the opposite. The easiest thing to do is to break the habit. Just like you only pick up the leash when you're about to take her out, you only touch the grinder when you're going to grind. Try taking it out, setting it on the counter, doing something else, shuffling it around, then putting it away. Tell her quiet whenever she barks. You're teaching her that it isn't going to be exciting every time you pull it out. You can also treat her for being quiet. If she seems to handle this, you can plug it in and pulse it a couple of times and walk away. Don't give her time to build up her excitement.

You have a few ways to go from here. You can either reward quietness, punish barking by sending her out of the room, or a combination of the two, which I would do. If she were quiet while I ran it for 10 seconds, I'd quite and treat her. I'd repeat. If she started barking, I'd ask her to be quiet. If she wasn't I'd send her out of the room. Distance from an object of excitement often dramatically reduces that excitement. You can also try giving her a distraction. I feel like it has a lower chance of success, because the grinder is probably more exciting that say, a kong of peanut butter, but it depends on the dog. Give these things a try and if they don't work, post back on this site, telling us what you tried and we can go from there. Good luck.