Cold Brewing (Home-Made)

Hi Barista Hustle community

There has been a trend of sort regarding cold brewing and I was wondering has anyone tried making it for themselves? I’ve done some research whereby you are supposed to soak the coffee beans in cold water for 12 to 24 hours. Is there a difference between one that has been brewing for 12 hours as compared to 24 hours? How does it affect the flavor notes? Is there such a thing as over-brewing for cold brewing?

I think cold brewing at home is how this whole trend started, as for an over extracted cold brew I don’t really know, the best way that I’d recommend doing is to get a jam jar or any air tight jar, do a ratio of 1:16 with the coffee/water, and then taste it at 8h-12h-16h-20h-24h, that will be able to 1- let you know the difference in taste between the hours and 2- you’ll be able to find the time in which your coffee tasted best! also play around with higher coffee to water ratios, as far as I’m aware cold brew should be stronger than a filter!

hope this helps!


Thanks a lot! I will try that out. In addition, do you know of any special/ specific equipments that helps with cold brewing?

none at all, I do mine with a jam jar and a V60 to filter it all! but you can change the filter depending on the type of body you’re after

Many people like these Nut Milk Bags(for making almond milk etc). They will strain the cold brew almost instantly. They leave a tiny bit of coffee silt. Paper filter/ V60 will give a cleaner cup mesh filter will give more body. You can also use both, first through the mesh and then through the paper since pouring a mid to large batch through a V60 can take a while.

The mesh bag~~~~

That looks very interesting! I would never thought of that, will try that soon. Now if only there is a bottle that I could do that hahah. Then I could cold brew and enjoy it on the go!

I see @nico does a 1:16 ratio. I’ve done as heavy as 1:6 to make a concentrate. Anybody else have thoughts on the ratio or why you do it?


How do concentrates work? I’ve varied between 1:13-1:18 and found that 1:14 and 1:15 worked best for me, and that was to create something I could drink as soon as I filtered it, but how/what do you use concentrates for?

I use 1:14 ratio, 80g of coffee. A great starting point is google for “prima coffee cold brew” for a primer on iced and cold brew.

Hot bloom is required for cold brew, otherwise left with a flat taste. Grind size determines brew time. I use 31A on Baratza Preciso for 12 hours in the refrigerator.

Filtering is important to clarify particles plus vacuum sealing hand pumps for jars allow the cold brew to not lose flavor over time, and last longer. I use Chemex filters (3) to finish filtering, expensive exercise though. Will try the suggested bag in this thread.


I never knew that about the hot bloom, how do you go about doing it?

Typically, pour approximately double of the coffee grind weight in water weight through the coffee grinds that is at brew temperature of the standard 200-205 degree F.

80g of coffee and then 160g of water as an example. Then the rest is poured through 1000g of “cold” water and then stored in refrigerator.

Hot bloom is no different in how most pour over coffee is started to allow the CO2 to complete outgassing and open up the grinds so that further pours have better solubility.


For our shop we do a 1:8.3 ratio, coarse ground, no hot bloom. 1:8.3 is basically 1lb:1gal of water which is good because atm we are going through so much cold brew that we have a couple different high school kids coming in morning and night to start or finish cold brew. I used to do all of it but we are making 100-150 gallons a week atm and it’s hard to keep up with the demand. Simple brew ratio means we don’t have to worry about the kids weighing things out. We then cut it 1:2 ratio which gives us in the end basically a 1:24 ratio.

We made our own cold brew blend that’s a 3 bean blend. The blend is purposefully roasted darker (rolling 2nd crack) for better solubility and more “robust” flavors. It’s our “house” cold brew blend. It’s made to appeal to a lot of customers. We found that people generally don’t like a high TDS coffee. Our cold brew comes in at 1.05 TDS after being cut and ready to serve. The other thing we do is only paper filter it so that there is still a good amount of fines in the brew. Gives a desirable mouthfeel.

Our house cold brew is basically a sell-out cold brew. We know it’s not incredible but it’s what customers love and it helps us pay the bills for the things we want to do - microlots, coffee cocktails, etc. In our area, speciality coffee isn’t huge yet. Most shops around us that have cold brew are using incredibly dark blends or old coffee. We put about a month and a half of research into trying 40 different cold brew blends and roasts focusing on both availability and price margins. We found that flavor acceptability in cold brew begins to drop dramatically on coffee over 12 days old. The difference is night and day.

We’ve also though got a cold brew of the month sort of thing just available in our shop. We normally try to do something way different. Africans or really cedar-y Indonesians. I cut it a bit less so the TDS is higher, there’s more to taste. I do a hot bloom on these ones if I feel like it helps flavor.

I don’t have a whole lot of science behind why we brew the way we do beyond experience and anecdotal evidence, but I’ve brewed over a thousand gallons of cold brew so if anyone has any questions about work flow or large scale brewing, I’d be happy to answer.

And if any shops out there are debating on doing cold brew, you should watch re-co’s whole cold brew coffee lecture series. One of them is from Diane Aylsworth who is the “vice president of cold brew” at Stumptown… it’s what pushed us into it, and we couldn’t be happier with it. We get tons of new customers and our margins are insane on it (about $25/gallon profit).


I’ve experimented with cold brewing in a bag using suisse voile - doesn’t contain all of the finer particles, but most of them settle out anyway. I prefer quite a concentrated cold brew - 5:1 water:coffee (by mass) - because it works better in milk based drinks.

Yeah we are working on a spiced cold brew for winter season. Nutmeg, all spice, cinnamon, maybe some cocoa nibs. But we mix that 1:1 concentrate/milk with a bit of simple syrup it’s really good.

Hey everyone,

I do a lot of R&I for Uel Zing Cold Brew and from my experience, cold brew has a lot of misconceptions surrounding roast, grind, time, temp… Cold brew does have its limits and though depending on method (drip vs immersion) and water temp.

Cold brew is just another method of brewing and like espresso it can accept every roast level that suits your preferences. The main factor is not roast level but roast development. As long as the beans are properly developed you should be fine brewing up any bean cold. For us we use all light roasted beans and have even cold brewed coffees from Tim Windelboe and Jacu with wonderful results - Super floral delicate notes from the Ethiopian, and tart juice goodness from a Kenyan.

Our ratios are 12.5:1 for Ready-T-Drink coffee and 6.25:1 for concentrate that is twice as strong as the RTD all using an immersion cloth filter method. This brew ratio is determined and linked directly to extraction. This is the first limit of cold immersion. It seems cold brew when done as an immersion hits its limit at around 18.5% extraction. So with this in mind we have settled on these ratios to deliver a 1.5%TDS RTD and 3.0%TDS concentrate. Cold drip does have it’s advantage when it comes to efficiency by using less coffee, and also be able to create even stronger concentrates. But it does have the added effort of dialing in grind.

Grind for immersion should be super coarse. Especially when done on bigger scales. The coarse grind will act as a more pours structure and allow the water to penetrate the grounds throughout the steeping process. A finer grind will yield you a steeper extraction curve for the first hour but after that it will level off more quickly and you run the risk of allowing the fines coffee to clump together and preventing the free flow of water.

Time- We do all cold brew at fridge temperatures. This requires a 24 hr steep vs 12 hrs but the result is better shelf life and a slower extraction that plays well with the inherently slow brewing process of cold brew.

Temp- The one thing I have found that I dislike about cold brew is when brewing very acidic coffees that have a dry or tart taste naturally i.e. Kenya and Malawi, the cold water tends to accent the dry, tea, tart flavors. In this case I find a hot bloom does help to develop the balancing sweetness of the coffee. For that we use 195 degree water and use twice the weight of the grounds, give it 5 minutes then too it off with cold water and place in the fridge. This will require a drastically less extraction period. More like 6-8 hrs.

I hope this is helpful information and feel free to hit me up on any follow ups.




I’ve been brewing cold brew since 2014 in small batches for our coffee shop in Mexico, but this summer we decided to start selling our concentrate in bottles. We use a system similar to Toddy Commercial to brew it, and we are thinking to bought a bigger system like the one in “Keg Outlet”.

Someone has tried?

And also I have a question for Austin (the UELZing guy). The other day on instagram they post a picture of your extraction curve, how does it work? I read about your coffee at the beginning of the year and I a big fan of your brand. I haven’t tried yet, but I love the things you post on your social media.

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Hey Fernando, thanks for the love. Yeah the cold brew extraction curve can be thaught of as an extremely drawn out version for an immersion method curve. That is to say most of the extraction, over 50%, will happen relatively quickly. Then it is just a slow increase that will hit its limit around 20% +- . This typically takes 24 hrs if steeped at cold temperatures, and shorter times as you increase the temperature of the environment it is being steeped. This initial extraction, what happens in the first 10 minutes, is extremely important especially if you are looking to scale up to large batches. As a frame of reference, you can cold brew in a small jar with 10g : 125g and achieve a finished ready to drink cold brew in as little as 30 minutes with a course grind. But as you scale up batch size and/or ratio, this extraction takes longer because an even saturation and initial extraction gets harder to achieve. The coffee in the center of the mass takes a lot more effort to get its solubles into the solution that surrounds it. We have found that by paying attention to the first ten minutes of the brew and settings benchmark for that will help make a consistent outcome.

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In my experience hot bloom has helped a lot with coffees with floral or fruity characteristics!

Nice fruity cold brew on ice in summer, nothing better

hi i’m also interested in your products for large batch brewing around 15 gallons but i am wondering about your metal filter. does it let in also of large particles so how does that effect taste and mouth feel. thx!

Hello Kittipat,

At Uel Zing we actually use a cotton filter for all of our could brew and allow for the silt from the grounds to settle out. We then drain out of the side. A smaller version for a visual is available on our web site,

Let me know if you have any other questions.

Austin Patterson