Whoaaa. seriously?

Downside is that if you're shipping bars, thin ones are more likely to break in transit.  A little bit of a low melt point fat actually increases flavor perception, believe it or not, as flavor release of fat soluble aromatics is a function of the melt characteristics of the fat system.  A chocolate bar that is softer (ie melts at a lower mp) will release it's flavors differently than a high mp bar, creating the perception of more flavor.  You're correct from the perspective of 'volume fraction' of flavorants - 2% milk fat addition will depress all other components by 2% - so straight-line mathematically there's less of everything else.

There is another option which I'm surprised that nobody has touched on, and that is to simply mold up a thinner bar.  Lots of advantages to this option, rather than adding a different fat to the bar.  While it won't make the chocolate "softer", it will be easier to break, and the flavour won't be diluted by the addition of more fat.

updated by @brad-churchill: 03/14/17 00:51:14

You will not be able to affect the softness change with your processing only.  IF (and this is a really, really BIG IF) you can control your bean sourcing to ONLY source beans (including the cocoa butter) from very high altitude trees, then you have some hope.  But i know of 3 people in the world (two who aren't typing at the moment) who can do this, and I suspect you're not one of them.

If you want to avoid milk entirely, you can get a similar affect by using small amount of liquid vegetable oil (or semisoft vegetable fat).  Note: doing so may result in your chocolate loosing its standard of identity (it's legal in some countries, but not others), and the more you use the more difficult it will be to temper (if not impossible.)

If you undertemper your chocolate, you can also achieve a textural softness, but you're playing with fire here, as, well, it's not really tempered any more, and you're likely to get bloom along with your softness (depending on your degree of temper, your bloom may  not show up for a week or longer, but it will show up).  Given the amount of information we have at this point, this is likely what happened in your first batch.  It will be very difficult for you to replicate consistently.

Edited to add: or my personal favorite, add some hazelnut paste and make it a gianduja.  Ranks high on the delicious-ometer, and it definitely softens it.

updated by @sebastian: 03/06/17 13:45:43

I'll definitely give the milk fat a try as a learning experience and to keep all my options open - thanks for the suggestion. But I'm still hoping for non-milk suggestions as there's milk allergies in my family (there's probably not enough protein in the milk fats to trigger an allergy, but that's not something I'll take a chance on), and having a 3 item ingredient (beans, cocoa butter, sugar) really calls to me.

I'll plan on changing one variable on every batch to see what happens. I'm hopeful I can figure out whatever I did in my first batch that made them so much softer.

That's true Sebastian 

To crackedcitrine - I would recommend trying it as a side by side comparison next time you're making a batch. When you're done grinding the chocolate, take half out and add 3-4% milk fat to the other half and continue grinding for 20-30 minutes. Mould the two batches up and taste them side by side.

You're spot on Gap! No reason to be intimidated at all  -  I'm not *that* terrifying....

This is geared completely to dark chocolate. I use a commercially made ghee that is 99.9% fat. 

Thanks for the tip gap, but is that advice geared more toward a milk chocolate rather than a dark chocolate?

A quick search says ghee has 0.5 - 1.0% water content. Is that low enough that you add it straight without the need for other additives like lecithin? I vaguely remember hearing chocolate is around that range, but I can't find it in writing at the moment.

It's a bit intimidating after that comment from Sebastian, but . . .

I would suggest adding some anhydrous milk fat (AMF). Adding 2% will start to soften the chocolate, but 4% may be necessary. 

If you don't have access to AMF (it can be tricky to get hold of) you can substitute ghee (often available from supermarkets or Indian grocers).

updated by @gap: 03/02/17 20:49:12

I'm going to refrain from answering as a challenge to those who have been taught this answer.  Yes, consider this a pop quiz 8-)

I'm still fairly new to making chocolate and extremely low volume, so please forgive any lack of proper terminology. And thank you to everyone that's already helped me tremendously as I read through older posts here.

I'm getting feedback that my 65% dark chocolate bars are too "hard", meaning they take too much effort to bite through, and even breaking the bars apart takes a significant amount of effort. I thought this was normal (many of the commercial bars in that 65% range seem similar) until I found a bar from my very first bean to bar batch from almost a year ago, and it is significantly easier to bite through.

My only recipe so far for bean to bar is for a 65% dark, using 35% sugar, 60% winnowed nibs, 5% cocoa butter (no lecithin since I haven't needed it for viscosity reasons). Assuming 50% cocoa butter in the nibs, that gives me a total cocoa butter content of 35%. My batch size is around 2.5 pounds, running in a home-sized Premier tilting melanger for about 36 hours (I haven't intentionally experimented with different grinding times yet - variation is purely a matter of convenience). The bars go into the refrigerator for 10-15 minutes until they start pulling away from the molds. They are removed from the molds and sit at room temp 15-60 minutes before packaging. They are stored in a wine refrigerator at about 60 degrees F.

My first batch seems like it is grittier, so maybe I didn't grind it as long, and maybe that's why it is softer. It was also a different bean source, and probably a much lighter roast.

I've considered the possibility that I'm overtempering, but I'm not finding detailed advice on how to check for that other than "once the melted chocolate starts to thicken" (I can recognize and correct that) or using an expensive temper meter.

Any advice on how to create easier to eat chocolate?

Thanks,
David