How to properly clean a whiskey flask?

Question

I found an old stainess steel flask that someone once gave me. I want to use it again to hold whiskey.

There doesn't seem to be any liquid inside, though it may have contained some just before the flask was forgotten.

How do I properly clean to start using it again? Just hot water? No soap? Can I trust it? It was only used to hold whiskey.

Answer 1

I'm answering my own question because I did a bunch of stuff from a lot of resources, and collected valuable information that more people may use in the future when coming across this post.

I wanted to use household items. My flask is a stainless steel with some copper.

What I actually did:

1. Cleaned with a small amount of tap water, shaking it a little bit;

2. Boiled a glass of water, and a bottle of vinegar/water (50%/50%);

3. Cleaned the flask with the boiled water, them with the vinegar solution (50% of the flask, shaking it a little bit). Then cleaned again with the boiled water (50% of the flask), shaking it, them with the vinegar solution again, then with the boiled water (50%), then with boiled water again (this time 100%). I didn't emptied the flask from this last cleaning;

4. I let the water inside for 24h;

5. 24h later, I opened the flask, and emptied it in a glass cup: there wasn't any solid particles, and the water didn't have any taste, so I believed it was ok to put some whiskey.

Maybe your flask is an old one, with leather, I don't know. In this case, I suggest you check these resources:

http://www.whiskywhiskywhisky.com/forum/viewtopic.php?f=16&t=4254

http://www.thetfp.com/tfp/tilted-knowledge-how/29045-cleaning-inside-antique-hip-flask.html

http://ask.metafilter.com/111820/Mildewsmelling-hip-flask-can-it-be-salvaged

http://forums.overclockers.co.uk/showthread.php?t=18080329

Answer 2

If there's no evil smell emanating from the flask, just give it a good rinse with hot water. Otherwise, a 20 minutes soak in a dilute solution of bleach (around 1 tbs per gallon), followed by extensive rinsing with warm water should do the trick.

Answer 3

Is the flask actually stainless, or merely something that's been plated bright and shiny? I'd go w vigorously shaking some sand around inside of it, to loosen any corrosion/crud deposits. Follow that w hot water/detergent, and brushing as possible. Finally, give it a soak in Vodka/Everclear. Check to see that the rinse solvent comes out clear and without chunks. For all you know, someone from the 1990's left Cream liqueur in there to evaporate.

Answer 4

Steradent tablets are best for cleaning any type of flask in my experience.

Answer 5

There are a number of flask and bottle brushes available online that will help with this task. I also found this set of instructions at ehow that recommends the use of boiling water and distilled white vinegar. Unlike most cleaning products, white vinegar will not leave a lingering scent in the flask.

Answer 6

I have always had a lot of success using uncooked rice as an abrasive and a dish soap/hot water combo. Shake it like crazy and it's clean. It's a safe, simple, and effective method.

Answer 7

Great question and some really good answers.

I am the founder/craftsman of a company that sells flasks and we recently wrote a blog post on it that can be found here: http://1776.co/blogs/journal/54690755-how-to-clean-your-leather-whiskey-flask

The short of it is:

Use warm soapy water and allow it to air-dry. Your flask should always be washed by hand because the chemicals in dish washing detergent may react with the stainless steel interior.