Will too fine of a grind make the shot taste off?

Sure. Here are a couple scenarios:

If the grind is too fine, then the pressurized water can crack the packed coffee cake resulting in a shot that is watery and under-extracted. In this scenario the shot runs fast.

If the water movers evenly through the packed coffee, but the grind size is too fine, then the coffee gets over-extracted, resulting in a bitter shot. In this scenario the shot runs slowly.

None of this is unique to hand grinders. If the water is too cold or too hot, you'll get off tastes. If the machine is not clean, you'll get off tastes. There are a lot of variables:

The Home Barista's Guide to Espresso

Bottomless Portafilter: Diagnosing Espresso Extraction Problems

If the grind is too fine, the shot will flow either very slowly or not at all (i.e. a shot that is choking your machine). Although I've occasionally had such very slow shots taste good if pulled on lever machines, usually they are unpleasant. To make a finer grind flow appropriately, you will need to lower the dose as well, which will tend to produce shots that are sweeter, and milder, than shots pulled with higher doses or coarser grinds. So what this means, in short, is that grinding "too fine" is relative to the dose you are using, as well as to the taste profile you are trying to achieve.

For more info on this sort of thing, see here: Espresso 101: How to Adjust Dose and Grind Setting by Taste

Also, and counter intuitively for me, if the grind is too fine on a lever espresso machine, you can get less crema than with a coarser grind. This might be more true on a spring lever than on a full manual lever.

Thanks guys, I've more reading to do! Seems an overload of information sometimes!

Just this morning I switched hand grinders and could immediately see that the grind was too fine. I tried to compensate by dosing less, but the puck fractured and I got the worst espresso I've had in months or years. My routine is so constant that I virtually never pull sink shots, but this one had to go. I had 2-3 more tries with the same grinder and did not get it dialed in.

So yes, some hand grinders can go way too fine. One result is a complete stall of the lever, where no amount of pressure will get an extraction. Then one needs to wait a long time before removing the portafilter. The other result can be a fractured puck and a fast watery extraction. Not sure which is worse.

A complication is a grinder that produces a very inconsistent grind with lots of both fines and large particles. These will choke the lever when too fine, but never be able to be dialed in, i.e. too fast when not too fine. I've had a couple of grinders like this, and they were useless for espresso.

I can easily grind so fine that I choke my machines with my Kym & Kym, ...produces surprisingly tasty shots when dialed in properly.

Good antique hand grinders produce great espresso, although not all are capable of this. I've never taken the trouble to discover why some work and some don't - I have a lifetime supply of the good ones. It would be interesting though, to look into the mechanics of why some are so much better than others, especially given all the hubbub about the C40, some of which seem to work worse than the bad antique grinders.

Good antique hand grinders produce great espresso, although not all are capable of this. I've never taken the trouble to discover why some work and some don't - I have a lifetime supply of the good ones. It would be interesting though, to look into the mechanics of why some are so much better than others, especially given all the hubbub about the C40, some of which seem to work worse than the bad antique grinders.

I suspect that some of this just comes down to the unique life history of each vintage grinder. If they are abused in ways that make it harder to get the burrs aligned just right, or that introduce slop into the mechanism, then you are never going to get good, let alone great, espresso out of them. Likewise, if the burrs get messed up, then none of the rest of it will matter. That is what makes buying these both fun and risky; you generally can't tell if a grinder will pull great shots until you clean it up and take it for a spin yourself.

True, some of it is based on use and/or abuse. But some is also burr and burr adjustment design. Those would be the features of interest for people wanting to design new grinders. The two I currently use most have been in more or less daily use for 10 years without any signs of deteriorating espresso quality. The shot I just pulled after dinner was very good in fact. Under normal use, therefore, it would appear to take a long time to wear out a set of burrs.

To look at the burrs on some of these old hand grinders, they look a lot alike. It seems the adjustments on some of them are different. I lucked out with an old PeDe grinder, it does a good job and I can fit the portafilter basket in the drawer to grind into, not all the coffee makes it into it, but it is easier.