I have brought back 50 pounds of beer twice from Belgium. You can buy really good adjustable folding cardboard holders that snugly encircle the bottles. Or I have used a length of bubble wrap, maybe 2-3 feet long, around EACH bottle.

Then I place each bottle inside a large Ziploc bag in case of breakage, which has never actually happened. I think the ones I use (reuse) are 12" by 16", but you can find them much larger online. Try uline.com or bagsunlimited.com.

People much more experienced that I at this tell me the big problem is bottle hitting bottle, not bottle getting hit from outside.

You can expect TSA to mess with them some.