Thanks so much for this great post. I'm getting ready to wash my first batch of yeast, from my Xmas Ale I'm bottling tomorrow and I have question that's not so much to do with the washing as it is with prepping the jars.
I just finished boiling my new mason jars and they came out with a white, hazy film on them. I scoured some canning forums and saw several places referring to this being common with water that has a lot of minerals in it. I live in San Diego and we have pretty hard water, so I assume these are just mineral deposits from the 20 minutes they spent boiling. The fix they suggest is to add some white vinegar to the water and that will get rid of the film. Obviously I can't do that if I'm using the water they are boiled in to suspend the yeast so my questions are:
1. Has anyone else had this problem? Is it mineral film? Or something to do with the new jars, maybe I needed to was them better?
2. Do you think the jars (and the water in them) are safe to use? Or should I dump them and start over.
3. In future batches do you think it makes sense to boil them in a vinegar spiked water to eliminate the film. Then drain them, like you would for canning, and fill them with either separately boiled water or distilled water?
Hopefully I'm worried about nothing but I thought I'd run it past the hive mind and see what comes back.
Thanks again.
I know it's been a while since the question of mineral deposits on boiled jars was posted, but I have the same problem and thought I'd share my way around it.
The whitish film on the jars is a mineral that precipitates during boiling. It will coat pretty much every surface that's in the pot with the boiling water, but a large majority of it will just fall to the bottom of the pot. In most cases this is calcium carbonate. See your water treatment chapter(s) in your homebrewing references more on this mineral in your water, how it affects temporary hardness, and how to get rid of most of it. The rest of this post is all about the later, getting rid of it.
Anyway, I have lots of calcium carbonate in my well water (source water). To get rid of it this is all I do. First boil about 5% more of the source water than I need for 15-20 min. in a large pot and let it cool to 100F or so. If you have a lot of mineral(s) in the source water you'll be able to see some crystaline stuff in the bottom and on the side of the pot. Keep the pot very still while cooling. Once cool, laddle the water out of the cooled pot into another vessel being careful not to disturb the settled minerals on the bottom or side of the pot. Now scrub and wash the pot real well with a kitchen scrubber. Dry the pot. If there's still any trace of whitish haze or mineral crystals in the pot a white vinegar wash should get rid of it for good, but rinse very well if you do.
Now pour the demineralized water back into the clean pot and use it to boil your jars etc. Then proceed on to yeast washing using this water.
Using this procedure my jars come out of the boil clear and clean. I've used yeast washed with this double boiled water for several batches now with superb results.
Please keep in mind that this procedure only removes (most of) the minerals that precipitate out at boiling. Any minerals that don't precipitate out at boiling are still left in the water, and unfortunately at a higher concentration than the source water because this boils some of the water away. Calcium carbonate usually makes up nearly all of the precipitate, but a few other minerals will precipitate as well, mostly other calcuim and magnesium salts. Refer to water treatment disucssions online and in your homebrewing (or chemistry) references for the behavior of other minerals and your local source water analaysis for what minerals are present in your source water.
BTW, as a side note, if you're doing anything else with boiled jars or bottles, like canning or baby formula, this same basic procedure works fine for that too. Also if you need to do this to keep your jars clean then don't forget to clean and flush your hot water heater frequently too because the bottom of your hot water tank is probably loaded with the same mineral precipitate.