Hey guys,
I bought a full set up from Keg Outlet about a year ago to cold brew coffee and nitrogen pour it from my keg fridge. I've made 10 or so batches in that time. I'm using a 1 to 1.5 ratio of lbs. of ground coffee to RO water, as suggested by the Cold Brew Guide that Keg Outlet offers. (I use a 2+ lbs. bag of beans, and roughly 3-ish gallons of water, based on what the grind yields.) I typically get a good end result. But, with the last couple of batches, I noticed the coffee was a bit sour. So, I did a bunch of research after the first sour batch and read about under absorption due to too little time in the brew, and also the size of the grind (too large) both contributing to sourness. I also thought maybe it was the coffee I used (Costco Medium Roast), but I'd used that successfully before. I also like to add about a 1/2 cup of simple syrup (brown sugar and RO water) to my ~2.25 gallon batches after the brew to mellow it out. I read that that might also be contributing to the sour. So, I changed everything up... I used better coffee--Starbucks medium roast, I used a slightly smaller grind and left it in a little longer in the fridge to brew (24 hrs instead of 20), and no simple syrup. I did all the things you're supposed to do: forced all of the oxygen out of the keg via the nitrogen line, and I'm using a Quick Cascade Nitro Coffee Keg Lid... and guess what? I got sour coffee again.
This morning, I came across yet another article about sour coffee and cold brew, and it talked about the gas used. This one talked about a "beer gas mixture" of nitrogen and how it can: 1. Create sourness and 2. Affect mouthfeel. I'm assuming that by "affect mouthfeel" they're talking about a slight fizziness, due to the CO2 that's in it, correct? And yep... my coffee does have a slightly fizzy mouthfeel.
So, after that LONG-WINDED explanation--I wanted you all to share in my pain--I figure I'm just looking for a confirmation on this from someone with experience: Could it be that I accidentally got a can of "beer gas mixture" nitrogen from Airgas? (And, in the future I need to tell them I need 100% nitrogen?) It'd be REALLY nice if the solution is this simple... I was thinking about throwing in the towel on cold brewing, 'cause I couldn't figure out why my batches were sour!
Thanks!
I bought a full set up from Keg Outlet about a year ago to cold brew coffee and nitrogen pour it from my keg fridge. I've made 10 or so batches in that time. I'm using a 1 to 1.5 ratio of lbs. of ground coffee to RO water, as suggested by the Cold Brew Guide that Keg Outlet offers. (I use a 2+ lbs. bag of beans, and roughly 3-ish gallons of water, based on what the grind yields.) I typically get a good end result. But, with the last couple of batches, I noticed the coffee was a bit sour. So, I did a bunch of research after the first sour batch and read about under absorption due to too little time in the brew, and also the size of the grind (too large) both contributing to sourness. I also thought maybe it was the coffee I used (Costco Medium Roast), but I'd used that successfully before. I also like to add about a 1/2 cup of simple syrup (brown sugar and RO water) to my ~2.25 gallon batches after the brew to mellow it out. I read that that might also be contributing to the sour. So, I changed everything up... I used better coffee--Starbucks medium roast, I used a slightly smaller grind and left it in a little longer in the fridge to brew (24 hrs instead of 20), and no simple syrup. I did all the things you're supposed to do: forced all of the oxygen out of the keg via the nitrogen line, and I'm using a Quick Cascade Nitro Coffee Keg Lid... and guess what? I got sour coffee again.
This morning, I came across yet another article about sour coffee and cold brew, and it talked about the gas used. This one talked about a "beer gas mixture" of nitrogen and how it can: 1. Create sourness and 2. Affect mouthfeel. I'm assuming that by "affect mouthfeel" they're talking about a slight fizziness, due to the CO2 that's in it, correct? And yep... my coffee does have a slightly fizzy mouthfeel.
So, after that LONG-WINDED explanation--I wanted you all to share in my pain--I figure I'm just looking for a confirmation on this from someone with experience: Could it be that I accidentally got a can of "beer gas mixture" nitrogen from Airgas? (And, in the future I need to tell them I need 100% nitrogen?) It'd be REALLY nice if the solution is this simple... I was thinking about throwing in the towel on cold brewing, 'cause I couldn't figure out why my batches were sour!
Thanks!
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