I use these with 32 oz mason jars and make two batches at a time. Easy to fill, easy to remove and most importantly NO COFFEE SLUDGE! I have two other cold brew systems the Bodum one from Target that looks like a giant French Press and a larger pitcher style from Walmart. Both require double straining or the inevitable coffee sludge in the bottom. The best part is just remove the bag and toss. I believe they’re compostable also. It works just like a tea bag.

Update: 6+ years later and I still continue to love these. I now prefer to use 2 bags in a 64 oz mason jar and I’ve added a pour spout. It’s still the easiest and most cost effective cold brew system out there. I also prefer to brew at room temp for a better extraction and then chill the final product after 18-24 hrs. If you use an espresso size grind there may be a little residue at the bottom but most pre ground coffee is medium coarseness and it will leave no coffee sludge. Happy brewing fellow coffee folk.

Simple and easy to use. I used 2 of
These with coffee in a pitcher and the cold brew was nice and smooth.

Almost too good means very little gets out other than a very fine dust but when you put the bags into the water, the bags/ground tend to float very high. I push them under and give a few gentle squeezes to get some of the air out. After a few hours, I will push them down a few times. By the end of the 24 hour cycle, they have soaked up the water and while floating, 99% is under the surface. I read that the bag takes 1.5 cups. I disagree with this. I use a 2 cup/64 oz water ratio and 1 cup just fits into the bag and still allowing room to tie it off neatly. I wish the bags were available in a larger size that would accommodate say 4 cups which would allow a nice loose pack of 2 cups to allow the water to freely circulate.
I tested these with my favorite cold brew recipe.. 2 cups of Sumatra ( starbucks) and 64 oz of water for 24 hours on the counter( not the fridge). The warmer ambient air works well at drawing out a lot of flavor. I lose about 8 oz of water to absorption which I add back when bottled. I use this straight up in a cup filled 2/3 coffee and 1/3 milk, no sweetener. This give a very nice nuanced cup with chocolate overtones. The dark roast holds up well to the milk and the ice slowly melting ( a yeti style 20 oz cup). I would not recommend this style for pure straight ice coffee.. it's a bit aggressive for that

I’ve used a Toddy for a couple of years to do
cold brew concentrate and it is great, if a bit fussy and doesn’t result in much concentrate in the end even though one has to use a lot of coffee. I wanted something easier, so I looked into and purchased one of those decanter/cold brewers with reusable micro filters. It resulted in an acceptable brew that I could drink practically straight, but hardly a concentrate. So I tried these bags. I had the advantage of having tried some that my mother had brewed before — she only drinks decaf so I knew it wouldn’t be exactly the same, but since it was my home roast I could gauge it anyway. I was convinced. But also convinced that there was no way one of these bags could brew a half-gallon or two bags a whole gallon of concentrate. I did a fine grind of some of my Columbian home roast (Full City) and used two bags placed in my 1.7L cold brewing decanter and left them to steep in filtered water in the fridge overnight. The result was a robust cold brew concentrate that I can use in a little over 1:1 concentrate:water ratio. It tastes fantastic and just as good as what I used to get from the Toddy. But, I would recommend they change their marketing because telling people one bag per 1/2 gallon is deceptive.

I first ordered these bags to make cold-brew coffee concentrate in bulk when catering an outdoor, off-grid event, but after reading reviews and testing it out discovered they're just as great for making big batches of hot coffee as well. I boiled a gallon of water, put the right amount of coffee into the bag, tied it off, then let it steep like a giant tea bag (but full of coffee grounds, obviously) for 5-10 minutes.

Which I wouldn't say that was the best coffee I've ever had in my life (though it was as good as any I've had from a drip coffee maker), it's an incredibly convenient way to make big batches of coffee when electricity isn't available (most stovetop/campfire percolators max out at 64 ounces and take a while to perk). I also attached the long string that holds the bag shut to the rim of the pot with a binder clip, as the grounds tended to come out of the top when I let the bag lie flat on the bottom.

The only slight inconvenience was squeezing the water out of the grounds to get the strongest brew. When making cold brew this is simple- squeeze the bag with clean hands and you're set. For hot brew I ended up using a couple of metal pancake turners to squeeze out the hot water when removing it from the pot. Still, it's a relatively small annoyance for making BIG batches of coffee for groups.

As a bonus- the disposable nature of the bags meant I could pre-fill a few dozen bags and then drop them in a gallon of boiling water in the morning. When making my first cup of morning coffee over an open flame, in cold weather, before the sun has even started to come up- anything that simplifies the task is helpful. These are a cost-effective, low-fuss, low-effort solution and I'll definitely buy them again in the future.