I'm looking to make an occasional decaf drink, and found that the replacement hopper is too expensive.

My machine is new to me, so I really don't have an idea as to how to proceed without a hopper. I'm guessing single dosing?

For the K30, how many grams will I lose after removing the hopper?

Unfortunately, a lot. You're looking at another 60-80g in the grinder throat once the hopper is off. Not a good grinder for swapping beans often and single dosing doesn't work well. You're better off getting a refurb B Vario for the decaf duty.

Agreed. I see this a lot on here. People buy a "commercial grinder" and want to make it perfect for home use. Mahlkonig didn't think once about how to single dose their grinder. If I wanted to single dose I would buy a single dose grinder. Which unfortunately there aren't many.... These companies don't make money off home users much to people's dismay.

You could scoop out all the beans from the throat and only lose 10-15 grams (not sure on this number). Or create an acrylic cylinder for a hopper replacement. Lots of threads on that. It's possible but not an "easy" fix.

I do understand the frustrations of losing coffee due to retention because coffee is expensive. It's a huge battle I have witnessed on this website. If it were an easy fix we wouldn't see a thread a day about the issue.

I do the acrylic tube so it fits under my cabinets. Scooping out the throat would be a huge PITA. By the time I did it once, I'd have bought a new grinder for decaf. I instead decided I'd drink hot chocolate or nothing after dinner rather than figure out how to work decaf into my life.

True story +1 times a million. Decaf doesn't seem worth the effort but do realize for some people it might be. I just make a cup of tea if I want something hot and delicious.

Well then, I guess I'll thank you all for the replies, and tell my wife to pony up for a grinder, or continue to go coffee-less in the evenings.

Just ran into this problem recently with some guests for whom I bought decaf beans. My Orphan Espresso Lido 2 hand grinder serves me well for such instances. Takes a little trial and error to nail the grind.

I think you took my reply the wrong way. It's just a little ridiculous to want that much from a "commercial" grinder. Like suggested maybe get a decent hand grinder for decaf beans?