The cold-brewed coffee we made was weak and tasteless. I spent an hour with the roaster to get the grind right but here are the steps and process:

  1. Purchased coffee, and requested that they be ground to "drip grind" coarseness
  2. 4 to 1 by volume (measuring cup) room temperature water to coffee grounds
  3. Stirred in the jar then refrigerated for 24 hours
  4. Poured it manually through a paper filter

Result: as I was pouring the coffee through the water filter, I could tell that the coffee looked kind of translucent. The taste was weak and bland. There was no complexity, and while it was not bitter, it was very bland.

So here is the paradox that perplexes me. I'm pretty sure that the grind is still too fine, but then on the other hand the coffee seems to be in on the weak side. The brew process is somewhat simple, but "immersion" is a standard acceptable cold brew process.

What do you think we did wrong? Let's assume that the beans were of decent quality.

  • Possible duplicate of Cold Brew Coffee at home?
    – MTSan
    Mar 22, 2017 at 18:53
  • 3
    4-to-1 is a fine ratio, as long as you are talking by weight (e.g., 0.5kg coffee to 2L water, or approximately 1 pound coffee to 1/2 gallon of water) If you mean 4-to-1 by weight, would you edit your question to clarify?
    – hoc_age
    Mar 24, 2017 at 3:54
  • Yes, 4:1 by weight is very different from 4:1 by volume - so which do you mean?
    – Ecnerwal
    Mar 24, 2017 at 15:04

4 Answers 4


The way you describe it is definitely correct for a cold brew concentrate. Refrigerated or not shouldn't matter to the degree you are describing. I think there are 2 options.

First is that the roast is underdeveloped, the beans are old and stale or of bad quality. In that case there's nothing you can do, except getting different beans.

The second option is that your expectations are off. However the way you describe the lack of taste I'd say it is probably the first option.

Vietnamese coffee is usually Robusta which lacks flavor compared to Arabica. I never tried to cold brew Robusta as it is usually used in Espresso blends, but what you describe is kind of what I'd expect to get (except I'd have guessed it would be bitter). Vietnamese coffees also tend to be on the darker roast side, as they are commonly served with sweetened condensed milk, while cold brew works best with lighter roasts. A lighter roast means also that more of the fruity, floral and acidic flavors are retained in the bean which adds to the complexity of the cup. Washed Ethiopian coffees or Central American coffees work best in my opinion. I prefer washed, but natural works as well. With natural coffees cold brew will usually bring out the red berry flavors even more and sometimes it can be too much in my opinion. Especially when making a concentrate as you are trying to do.

So get some quality light roast Arabica beans and try it again I suggest, because your setup and process is fine.

  • Avocado1 - I'm not familiar with the washed and natural terms as it relates to coffee. Can you enlightened us a bit? Much appreciated. Mar 23, 2017 at 16:24
  • Washed and natural refers to the processing of the coffee cherry after harvest. Natural coffees are dried flat on the earth for several weeks with the flesh still on the bean. The flesh is removed after the drying process is done. Washed or wet-processed coffees get de-pulped in a so called pulper immediately after the harvest and then ferment for a few days in water.
    – avocado1
    Mar 23, 2017 at 20:28

Avocado1, thanks and I think your explanation is probably on the right track. The employees at the PV roasters were very reluctant towards making a coarser grind - I really had to push them. Also the roast I used was recommended by someone from their firm for a cold brew. Since I've been in Vietnam, I used the phim filter style of brewing and with the sweetened condensed milk. The first time I visited them, they pushed towards their robusta, but I told them that I only drink arabica, which they also have from the mountainous Da Lat area. Anyway, I appreciate your response and input and will try using one of their arabica blends for the cold brew. Also as an American, I have to say that the Vietnamese are a really friendly people. Yes our coffee cultures may be different but I have nothing but love, respect and admiration for them.


The problem is probably temperature of the water when steeping. For a better, more full-bodied result, steep at room temperature. Seattle Coffee Gear, for example, did a test of cold-brewing in the refrigerator and at room temperature, and reported that the room-temperature-steeped cold-brew was tastier, stronger, and more full-bodied. See also this question for more.

In sum, don't refrigerate it until it's done brewing. Your fridge slows the extraction process down.

  • Please do cite some references to help explain your answer; short answers are not generally viewed favorably; see How to Answer for more. I took the liberty of expanding for example.
    – hoc_age
    Mar 24, 2017 at 3:41

The best way to improve cold brew is to brew your coffee hot and to let it chill in the fridge. :) Acidity is delicious, and cold brewing coffee dampens the acidity. If you are dumping cream into it, then totally cold brew it, but otherwise hot is the way to go.

Otherwise, I would personally take it out of the fridge, only brew it for 12 hours, and ask them to grind it for more a french press sort of grind (coarser!).

  • That is why you should use light-roasts of washed coffees with naturally high levels of acidity like Ethiopian or Kenyan coffees. Cold brewing them will bring out the sweetness and more delicate flavors. Sure acidity brings complexity into your coffee, but sweetness is arguably the most important quality in a good cup of coffee. These coffees will however still have a good amount of acidity. Even a light-roasted natural Ethiopian is high enough in acidity to cold brew. You will get very nice (straw-, black-, rasp-,...)berry flavors. Dark roasts however don't work well for lack of acidity.
    – avocado1
    Mar 27, 2017 at 12:23
  • I'm still going to have to disagree with you on this one. I've used fantastic coffees from all sorts of regions (I'm sort of an African fanboy myself), and no matter what, the acidity just has this distinctive "cold brew" vibe about it that I just do not enjoy. It's very one dimensional, and dominates the entire drink. Even cold brewing a gnarly Kenyan coffee just doesn't do justice, and totally kills the acidity. You're right that sweetness is important, but with out nice acidity you are just drinking flat soda.
    – Induction
    Mar 29, 2017 at 23:31
  • We don't have to agree, in the end it's a matter of preference and taste. I partly agree if we're talking one of those 1:10 coffee to water ratio cold brews. They just suck (kinda like flat soda) and I don't understand why people like that stuff. But a 1:4(up to around 6) ratio leaves plenty of acidity if the roast is right. If you enjoy chilled pour overs more, by all means go for it. It's just not a cold brew as it brings out very different flavors and is obviously prepared in a very different way. You'll never get the sweetness of a cold brew by chilling pour overs ceteris paribus.
    – avocado1
    Mar 31, 2017 at 0:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.