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Adding Cold-Brewed Coffee to Your Beer

2010 January 25
by Mad Alchemist

Ever try adding coffee to your boil or brewing some up then adding it before bottling or kegging your beer? Did you get a difficult-to-predict level of bitterness and acid bite? That’s because it was hot! If, instead, you want the taste and aroma of a delicious coffee (and the caffeine, too) in your beer without as much bitterness and bite, you can try to cold-brew it instead.

There are really two ways to cold-brew coffee for your beer. The first is to brew it in your fermentor. To do this, you’ll need to wait until primary fermentation has completed (to be safe, wait a couple days after all the bubbling has quieted down).

Then, you can add coarsely ground coffee beans directly to your secondary in a muslin bag. Be sure to sanitize the coffee (you can do this with some cheap vodka, but ditch the liquid before putting the beans into the secondary). The longer you leave it in secondary, the more likely you are to get astringent flavors and smells from the coffee, so it’s probably best to leave it in for one to three days.

Want to avoid the secondary and increased potential for astringent flavors? Cold-brew it and add it before bottling or kegging. To cold-brew coffee, you probably have everything you could need as a brewer. You’ll need a sanitized vessel that can hold 40+ oz (5 cups), sanitized water, sanitized beans, something (sanitized) to grind the beans with, and something to strain the beans out of the liquid with (e.g. a muslin bag).

The process is very simple (remember to sanitize):

  1. Coarsely grind 8 oz of coffee beans. Put the coffee beans in a muslin bag. Put the bag of ground coffee in the vessel you’ve selected.
  2. Add about 4 times as much water to the vessel as coffee beans, which translates to 4 cups in this case.
  3. Cover your vessel with foil or plastic wrap, then throw it in the fridge for 12+ hours.
  4. Pull the muslin bag of coffee grounds out. Let them drip for 15-30 minutes to get all the liquid out (a sanitized strainer would come in handy here). You might also want to extract as much of the flavor as possible by dipping it in one or two more times and letting it drip again.

Now, you have a nicely concentrated amount of cold-brewed coffee. All you have to do now is add this along with your priming sugar before bottling/kegging. This also has the added benefit that you can bottle some without the coffee, then add it for a specific portion of the beer. Two beers in one!

How much should you use for a 5 gallon batch? Consider starting small. Try half of the above recipe (about 2 cups) in the entire 5 gallon batch. Then, add 1 more cup to the second half (this is what it would taste like if you used all 4 cups of coffee in the entire batch). Drink the fourth cup of cold-brewed coffee.

One more added benefit to cold-brewing the coffee and adding it before bottling/kegging is that you see if you’re doing it right without destroying a batch of beer. Just do all of the steps mentioned except adding the coffee to the beer and taste the coffee to see if it’s any good. If it is, it should be good to put in the beer. You can also try adding a small amount to a beer you know is good to see if the flavors blend well (try adding 1.2 tbsp of the concentrate to a 12 oz bottle of porter or stout to get a roughly equivalent taste).

If you’re really concerned about sanitation or are too lazy to sanitize each piece of the cold-brewing equipment and ingredients, I suspect you can boil the cold-brewed coffee along with (or in a separate pot from) your priming sugar. This will likely change the taste profile somewhat, perhaps giving it a caramelized/roasted flavor but still less astringent than a hot-brewed coffee. Never tried it. Have you? Tell me of your experiment! I’ll give this a try soon to see how it turns out.

In summary, coffee doesn’t just have to be added to the boil. You can also cold-brew the coffee either in a fermentor or by itself, then add it before bottling/kegging. As with everything experimental, experiment!

17 Responses leave one →
  1. Ryan permalink
    December 22, 2010

    You should clarify that the 8 oz. of beans you prescribe are 8 fluid ounces, or 1 cup. 8 0z. of beans (1/2 lb.) is much more than that. If weighing the beans, it’s closer to 2 oz. ground beans.

  2. March 13, 2011

    I love cold brew and I love brewing my own…interesting idea to combine them!
    But, how do you sanitize the beans?

  3. Carl permalink
    May 17, 2012

    Do the oils from the cold-brewed coffee have any affect on head retention?

  4. September 11, 2012

    The beauty of cold-brewing the coffee is no oils, therefore no head-loss (in fact I found my coffee stout trial had better head production and retention than the regular stout!

    The trial is going to full-brew size this week, with the cold-brewed coffee being added as the beer goes into cask. A lovely, smooth-tasting product, thanks to cold-brewing the coffee…

  5. Little Pat permalink
    May 11, 2013

    Good one Mad I’ve been doing a little brewing over the last 13 years and stumbled on some coffee stout whitch was to my likeing so I thought I would give it a go . Look on the Net I WAS TOLD , yey there is a lot crap when one only want’s a simple ansewer thanks for this I’ll try your angle and let you know how I went.

  6. June 17, 2013


    Adjusted method after some trial and error – 12kg of freshly ground coffee (for a 200 UK gallon brew), in fine meshed bags, suspended in the fermenter for final 2 days of fermentation (after the beer has been cooled down to 11 degrees centigrade). This gives the most intense, yet smooth flavour.

    The resulting brew went on to be a festival champion.

  7. Little Pat permalink
    April 6, 2014

    I ended up doing 2 oz. for 20 hrs in the fridge , then dropped the strained liquid into vat one day before bottling up . I put it in an old ale kit instead of the stout .Good head and a very clean flavour , thanks for the info. will try it in a stout now.

  8. May 9, 2014

    That’s good to hear, Pat 🙂

    I’ve come back to this, as our method has now altered…

    I know our kit is, perhaps, slightly different due to scale of operation, but this should be transferable. Mad Alchemist mentions using a fermenter for cold brewing, which is effectively what happens now. The hot wort is transferred to fermentor via a heat exchanger, and the yeast pitched and left for 48-72 hours before the refrigeration is turned on to crash cool. 24 hours later the mesh bags of freshly roasted and ground coffee are added to the fermenter for the final 48-72 hours prior to racking into casks. The coffee is therefore cold brewed for a longer period, giving rise to an even more intense flavour.

    The option here is that you could reduce your coffee costs, as more flavour is obtained during the longer cold-brew process. We choose to maintain the amount of coffee for the stronger flavours.

    One point of note is to remember that this also gives maximum caffeine extraction – my back-of-an-envelope calculations suggest a pint of our Mocha Moggy contains one and a half shots of espresso. Customers drinking a few pints have reported trouble sleeping, so perhaps best drunk earlier in the day, or in moderation…

    Hope this proves of interest 🙂

  9. August 23, 2014

    Thanks for all the tips, Chris!

  10. Mad Mark permalink
    January 18, 2016

    I used my Coffee Machine too make enough for 6-8 Mugs and let it go cold (over 3 days) then and pourer in too a Glass Demijon added a packet of Ale Yeast and a Tablespoon of Demerara Sugar which I hope that s going too produce a Coffee Ale! 😉 as I LOVE Coffee as much as I LOVE Ale!! 😉

  11. January 18, 2016

    You are mad, Mark.

  12. Mad Mark permalink
    January 18, 2016

    Forgot 2 say that I had added Crushed Barley & Chocolate Grains and warmed then too just below Boiling before I cooled too 20 degrees before I added Sugar & Yeast! 😉

  13. Marisa permalink
    February 5, 2016

    Question: How long do the coffee beans need to soak in vodka to be sanitized adequately?

    Really appreciate this thread. Have a stout that’s finishing primary fermentation and want to add cold-brewed coffee this weekend.

  14. Chris permalink
    September 23, 2016

    Hi Marisa,

    (hope Mad Alchemist doesn’t mind the comment?)

    We use freshly roasted and ground beans, which we don’t additionally sanitise – can’t see the need – the alcohol in the beer helps some. You could (if worried) re-heat in an oven to be sure, but if taken from a clean container, you should be fine…

    Just my take, but we’ve had no problems in multiple brews 🙂

  15. Chris permalink
    September 23, 2016

    As a side comment, we’ve had great fun infusing fruit teas in golden ales, using the same principle. We DO pour boiling water over the tea (in giant tea bags) to sterilise somewhat before infusion. Only the minimum of water, which we add to the brew with the tea.

    Fruit tisanes are very effective at adding flavours 🙂

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