Pouring boiled water into kegs

[TexasGuy]

I am going to keg iced tea and cold brew and dispense using nitrogen or argon. I'm thinking through my sanitization practices to extend refrigerated shelf life.

Are there any concerns with pouring boiling water into a sanitized keg and letting it cool?

For iced tea, I would boil and steep in the kettle, pour it while still hot into a sanitized keg. Then refrigerate, tap and dispense.

For the cold brew coffee, I'm sterilizing the water through boiling. Add to a sanitized keg while hot to cool it. Closed transfer to a sealed vessel for soaking process, then closed transfer/filter to another keg for service. I still have the issue of the coffee grounds not being sanitized, but I'm at least removing the concern of the water not being sterilized.

Are there concerns with the keg remaining sealed once the water cools and the pressure releases? Are any of you kegging their tea and coffee?

Thank you for your feedback.

 

[day_trippr]

Cornelius keg lids aren't designed to support negative internal pressure and may admit air as the water cools. The other potential issue is softening the glue that bonds the rubber base - if your keg has one...

Cheers!

 

[TexasGuy]

So, the negative pressure is what I was mainly thinking of. I could pressurize it while it cools. Thank you.

Did not consider the glued base. If it comes off, I'll report back after I reattach it with some construction adhesive.

 

[Beekeeper]

I pressurize while cooling, and nowadays only introduce pasteurization range temperatures into corny kegs. I have 'softened' a couple of bases with boiling temperature in the past. Those kegs are still in use, and I have made a couple attempts at re-bonding using marine adhesives.

 

[day_trippr]

If you use 160°F water and wrap a couple of towels around the keg so the temp drops 20°F or less over 30 minutes, it'll be pasteurized in the end...

Cheers!

 

[mashdar]

FWIW, FDA requires botulism control for cold brew coffee. There was some big recall recently because a company had not documented any strategy.
https://www.fda.gov/safety/recalls-...-products-due-potential-clostridium-botulinum

I can't say it is or isn't an issue, but you might consider acidification. edit: I guess low acid is part of the point? Sounds like storing is slightly sketchy. Is this for home use?

edit: here's a good read
https://nationalcoffee.blog/2022/08/24/cold-brew-safety-what-you-need-to-know/
except most of the good info requires membership

 

[hotbeer]

Are there any concerns with pouring boiling water into....

Don't wear flip flops or be bare footed while pouring the boiling water. Wear proper shoes of most any sort.

 

[Deadalus]

You could potentially go the extract route as far as chilling and make the tea concentrated in the kettle. Add cold water to the keg and pour the tea in. That's what I do with smaller batches of kombucha (a gallon).

 

[pvtpublic]

Umm... boil it in your boil kettle then use your chiller? Sanitize with StarSan?

 

[mashdar]

I think OP is talking about cold brew coffee, folks : )

edit: I'm a dummy and missed the iced tea bit. I cold extract my iced tea, too, but I know that's not the norm.

 

[pvtpublic]

I think OP is talking about cold brew coffee, folks : )

You're right, but we're answering the questions regarding sanitization of the brew water and keg.

 

[Deadalus]

...and also iced tea. What was asked initially was any issues with using boiling water (brew water) in [on] the keg and then also sanitation issues afterward appear to be a concern for iced tea and cold brew coffee.

It might be helpful to discuss what might affect iced tea and cold brew coffee as far as microorganisms and such as that is potentially different than finished beer. I mentioned concentrating the product but that would be more for hot brewed tea. I'd add to what I said and suggest perhaps using sanitized water--"boiled" and cooled as one possibility. I put the boiled in parantheses because as @day_trippr mentioned, water doesn't have to be boiled to be treated. There are guidelines for how long to keep water at sub-boiling temperatures in order to treat it. As a tea drinker, a smoother tea can be had by not boiling the water. It's a finer point about tea preparation that is sometimes unknown to even regular tea drinkers. Also, an immersion chiller could be used for hot tea which was also mentioned. I don't know much about cold brew coffee. I wouldn't want it anywhere near my equipment either. I don't even allow coffee in my tea mug!

 

[Broken Crow]

I am going to keg iced tea and cold brew and dispense using nitrogen or argon. I'm thinking through my sanitization practices to extend refrigerated shelf life.

Are there any concerns with pouring boiling water into a sanitized keg and letting it cool?

For iced tea, I would boil and steep in the kettle, pour it while still hot into a sanitized keg. Then refrigerate, tap and dispense.

For the cold brew coffee, I'm sterilizing the water through boiling. Add to a sanitized keg while hot to cool it. Closed transfer to a sealed vessel for soaking process, then closed transfer/filter to another keg for service. I still have the issue of the coffee grounds not being sanitized, but I'm at least removing the concern of the water not being sterilized.

Are there concerns with the keg remaining sealed once the water cools and the pressure releases? Are any of you kegging their tea and coffee?

Thank you for your feedback.

One possible concern not yet mentioned: What kegs are you using? Will this boiling water run through the post? If they're older genuine Cornelius, AEB or other models, the poppet has a hard plastic lower stem:

I've not been able to identify what type of hard plastic it is, but I have seen other hard plastics warp or fracture under temps exceeding 150°. The modern universal poppets as well as many others, are all SS (and whatever the o-ring is made of... though they are usually tolerant of temps at or above boiling) I'd also be concerned with the disconnects and their innards.
Just my 2-cents.