Many on this forum (and elsewhere) extol the virtues of the Nel/woodneck/sock/flannel pourover method. Someone in my office has one of the 'sock brewers' that he brought back from Costa Rica. He raved about the coffee this method produces. I made a batch with my own beans, freshly ground in one of my hand grinders, and it tested overwhelmingly like...cloth. I realized I hadn't wet the filter first, so the next day I made another batch, wetting the filter prior to adding grounds. Results were exactly the same - cloth flavored coffee. I figured that his filter was old/poorly maintained/mildew-y/etc. Since I generally enjoy pourover and like a challenge, I purchased a Hario Nel, and you guessed it, my first cup tasted like cloth.

Is there just a break in period for the filters? Do I need to run it through the dishwasher? Am I just missing something obvious?

I take a full electric kettle fresh off the boil and pour thru, dump, repeat, for a 5 minute or so period. Then I pour clean water thru and taste the results for taints. Repeat as needed.

Try boiling it in water for a little. Do this every so often (weekly), in addition to giving it a good hot water rising in the sink after every use. Also, store it in a zip lock bag in the fridge.

What Paul said--

I boiled my cloth filters for 5-10 minutes before making my first coffee with them. I boil them every 6 months or so to clean them but never use detergent. I learned the hard way using oxiclean or dish soap (reading people's recommendations on amazon before discovering HB). If I go many weeks without using it, I will boil them before using them again. Lately, I'm using them every day so I haven't done that for a few weeks.

Now, it's been at least 2 years since these have been 'new' so I totally forgot how long it took to break them in. But, I did just buy some replacements that are on the way so I'll have to break those in. I'll probably boil them for more than 10 minutes the first time. Hope that helps

Super helpful - thanks all.

Success! I kept the filter in a plastic bag in the fridge over the weekend (this setup is at work). I've read that some see this as an unnecessary step, so perhaps I'll leave it out today. Anyway, I ran it undert the hot water tap from our plumbed-in drip maker for a few minutes and then made the pourover as I would with a Chemex, and...a delicious cup with no cloth flavor. Thanks all!