I do like my cold brewed coffee but it's difficult and inconvenient for me to make and keep in work due to the time it takes to steep, shared fridge space, etc.

I came across this method recently...

The iced method isn’t complicated. Basically, you prepare brewed coffee as you normally would, only you use half hot water, half ice you put in the bottom of the vessel. The hot, fresh coffee drips directly onto ice so that it’s cool and ready to drink right away.

I've now tried it a few times using my small chemex and a ratio of 2:1 (water to ice) rather than 50:50. I'm trying the pour over much more slowly than I normally would to maximise the extraction while using less water.

I can't really fault the taste, the flavour is still great, the finish is less acidic but obviously more watery. So while this method is indeed quick and uncomplicated I'm curious about 2 things:

  • What else can I do to compensate for the extraction difference? I would really prefer it to be less watery.

  • Am I potentially going to crack the pot with the combination of hot and cold? I can't find any info on temperature variances on the Chemex site.

Edited to add information...

For a hot-brew I normally use using 300ml hot water for 21g of grind. Here I'm using 200ml hot water in the pour over, to compensate for the 100g of ice that melts.

I'm taking 6-7 minutes with the pour. Normally I would take 3 minutes.

I'm making my grind slightly finer in order to extend time it takes the water to drip through. I would consider it to be medium-fine.

  • It is hard to tell what you are asking. Your title is not reflected in the body of the question and vice versa. Perhaps you could edit your question to make it clearer. Commented Jun 10, 2015 at 13:03
  • 1
    I edited the title for clarity. I thought my questions were specific enough?
    – CMD
    Commented Jun 10, 2015 at 14:54
  • How long is your pour-over session? With 2.5-3 minutes for "normal" pour over for this amount, 5-6 minutes or more is probably reasonable for your case. How does this ratio of coffee (21g/300mL) taste to you as regular hot-brew -- strong enough or also weak?
    – hoc_age
    Commented Jun 11, 2015 at 14:38
  • Edited my question to add info. To my taste a cup of hot brew with the 21g/300ml ratio has a good flavour and is strong enough. Although the finish with this ice method has the same strength in terms of darkness/caffine content, the flavour in terms of taste/aroma is the same as if I had just added ice to a hot brew.
    – CMD
    Commented Jun 11, 2015 at 15:47

3 Answers 3


What you're talking about is the "Japanese iced coffee" method, which is hot-water brew directly over ice. In contrast, cold-brew is using cold water in contact with the grounds. See techniques at other questions tagged as .

This article from Counter Culture, also referenced in the article you linked, suggest Japanese iced as an alternative to cold brew. The articles suggest that directly brewing hot coffee over ice retains more of the volatile flavour compounds.

If you have had true cold-brew before, most methods use several times as much coffee grounds to brew as with other methods (some then dilute this with, e.g., water or milk). For example, normalized to a 200mL "cup" (~6.5 fl.oz.) of brewed coffee: Blue Bottle suggests about 3x more coffee for cold brew (45g per 200mL) than for drip (14g per 200mL). If you're coming from that strength, it's no wonder you're finding it watery.

To your first question: If you want a stronger brew, why not simply use more coffee grounds? Your amount (21g grounds to 300g water+ice is about 14g/200mL cup) is already at the higher end of the spectrum for drip coffee; the industry standard is closer to 7g per cup/dose. But if you want it stronger, use more beans!

On your other question: this temperature change shouldn't be an issue. You said you're using a Chemex (e.g., classic 3-cup) -- it is made from Pyrex brand borosilicate glass, which has very good thermal shock properties. Even a lesser glass (e.g., non-tempered soda-lime glass) shouldn't be a problem at these temperatures (slowly dripping boiling water onto ice). (However, for example, ice into glass at oven temperatures could certainly be a problem).

  • Great answer, thank you. Would you also recommend a finer grind or darker roast? I've considered experimenting with both. Now that I know I'm not going to break anything I think I should!
    – CMD
    Commented Jun 11, 2015 at 15:51
  • Grind: this will change the extraction and time as you noted in your edit to the question. If you go too fine a grind for a long brew, it might get "muddy" and not filter through; you might get more bitter notes with hot extraction. Try it out! :) You might also consider trying actual cold-brew, which can be done with limited fridge space.
    – hoc_age
    Commented Jun 12, 2015 at 17:56
  • Roast level: Counter Culture coffee (for example) says "any coffee any brew" meaning that any good-quality coffee, of any roast level, can be used in just about any brew method. Though there are some "more traditional" roasts for a given method, it's really personal preference. See some thoughts on my question about roast level for cold brew.
    – hoc_age
    Commented Jun 12, 2015 at 17:57
  • Your answer, and all the the links included, were very helpful. Though what helped most was the encouragement to experiment - I've been playing with both roast and grind for a few days now and have reached a taste I'm much happier with. Many thanks!
    – CMD
    Commented Jun 19, 2015 at 0:59

When I hear "cold brew" I think something like Dutch Coffee, or coffee brewed with cold water and long extraction times. Acidity likely wouldn't be reduced by cooling the coffee directly after, it's possible that the melted ice is just diluting your brew and cooler temperature mellows out the taste of the acidity.

There are many ways of cold brewing. Some involve full immersion for a long extraction time, like Toddy. Others slowly drip cold water or ice melt into grounds using a drip tower. The second method is often prefered and offers the most balanced extraction. However, I've had Toddy before and it does alright. Toddy might be the less expensive method, but for a plastic bin and some big paper filters I feel like a drip tower is better worth the money if you can find one for a reasonable price. You can find some drip tower/dutch coffee makers on ebay in the $90 range.

As far as I'm concerned, however, you are not cold brewing. You're just making iced coffee. I do something similar with an Aeropress. The Aeropress I would prefer for iced coffee, as it brews a concentrate. I've noticed little difference in acidity, it may seem more mild simply because it's cold and acids tend to mellow out at cooler temperatures, but once ingested its all the same(hot or cold) if you're trying to ward of acid reflux or similar. Cold brewing would actually make the coffee less acidic, rather than just mellowing out the taste of acidity.

If you're interested in trying the Aeropress method, I'd highly recommend it if you enjoy iced coffee. You press the aeropress directly over ice, and it melts the ice to form a perfect ratio of concentrate and water. Whereas most other methods are either diluted, or take time to cool. This method produces iced coffee in the same amount of time it takes to make a hot cup of coffee with the Aeropress(1-5min), without diluting the coffee. It accomplishes basically what you're intending to do, but with the aeropress rather than the chemex. This method will take less time, produce a stronger cup, and is a bit cheaper(the aeropress is pretty cheap). You can brew a cup when you want it, rather than prepping coffee ahead of time.

  • I have to admit that this Aeropress method actually makes more sense than my own Chemex method - I'll try it. I don't actually own an Aeropress so this is a good excuse to buy one!
    – CMD
    Commented Jun 19, 2015 at 1:02

Ever considered cooling your coffee down to 40 degrees immediately after you brew it? This would keep the freshness as well as not dilute it. Check out this link.

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