Cold Brew White Particulates?

[friendofacoffeefiend]

I recently cold brewed some coffee at home using a french press, leaving it to brew for around 15 hours at room temperature. After I pressed the solution and emptied the concentrate into a small container, I immediately put it in the fridge. 2 days later I opened the container and found a small amount of white particulates floating on the top, as well as some sludge on the bottom of the container. I imagine the sludge is from using a french press to separate the grinds from the concentrate instead of cheese cloth or a coffee filter, but I am lost on the particulates. They don't look like mold growths since they're individual and about the size of the coffee grinds. Also, at no point post-brewing was the concentrate left in the danger zone (41°F to 135°F).

I'm concerned because I was considering selling cold brew coffee at the shop I work at because it's absolutely delicious, and I've read that this concentrate should last a pretty decent amount of time in the fridge before spoiling. Help?

Thanks,
A Friend of a Friend of a Coffee Fiend

 

[PinkRose]

Hello "A Friend of a Friend of a Coffee Fiend"

Welcome to the Coffee Forums website!

We have a lot of Forum members who cold brew their coffee, and hopefully someone will have shared your experience and be able to tell you what happpened.

Did the white particles look like the fat that rises to the top of things like home-made broths and chicken juices when you refrigerate them? I'm wondering if it was the oils from the coffee, and some of it hardened like chicken fat.

I have a feeling you're going to end up buying a cold coffee brewer in the near future.

Rose

 

[SlowVeryGood]

I've been cold coffee brewing and selling the brew at festivals for two whole years and never experienced anything like you just described. Is this repeatedly happening? Perhaps it was just some fluke. Don't give up making cold brew. It's so superior for iced beverages. Toddy sells a brewer, but it's no more than a food-safe 5-gallon bucket. The bucket is lined with a nylon mesh bag that fits over the rim and is lined with another paper filter bag. Clean up is easy - just dispose of the inner paper bag which hold the grounds. I've brewed hundreds of pounds of coffee with no white residue. The brew concentrate will last many days even at room temperature, though you'll never have the brew around that long.

SlowVeryGood

 

[friendofacoffeefiend]

Thanks so much! The particulates didn't look like oils, as they were less than a mil. long and were some what suspended throughout the concentrate. Perhaps it was some bizarre fluke.

 

[PinkRose]

Were you ever successful when you cold brewed coffee using the French Press? Is it possible that the French Press wasn't totally clean? (dish soap residue, etc) It would be interesting to know what happens if you try to do it again.

Rose

 

[eldub]

We made our first batch of toddy last week and it turned out swell.

The only complaint I have is that the recommended dilution of one part concentrate to three parts water was too weak for everyone involved. So maybe keep that in mind when figuring out price/cup when calculating cost/profit. Our group preferred two parts water to one part concentrate.

lw

 

[LeeDenney]

I've never had this happen while cold-brewing either.

~Lee

 

[SlowVeryGood]

It shouldn't matter what method you use to strain the grinds. I used the french press a lot when I was first experimenting with formulas. The batch will have more strength if you brew it for 24 hours. There is never any bitterness in a cold-brew. The strength is also impacted by the ratio of ground coffee to water when brewing. You didn't mention that ratio. We use five pounds of coffee beans to 14-15 quarts of water. You will end up with about 2.5 gallons of concentrate. Also experiment with different beans. The results will differ. Even though cold brew removes most of the acidity, we still found that many of the higher acid beans from Central America make the most flavorful cup.
SlowVeryGood