Star-san storage life

[EamusCatuli]

Quick Question:

I have a bottling bucket full of star-san solution that was used yesterday. I covered it up, and would like to use the same solution today. Can I do this? How long does the stuff last?

 

[FlyGuy]

If you make up your Star San solution from de-mineralized water (e.g. reverse osmosis water), it will last for months and months. There are two criteria to check it -- the pH must be below 3.5 to be effective, and it should not be cloudy.

If you make your Star San up with tap water, it may go cloudy within a few days. Also, if you use it to sanitize equipment that isn't cleaned well first, it may go cloudy or its pH may rise. In these cases, you are best to make up a fresh batch.

 

[Big10Seaner]

I do it all the time if I'm just using it the next day. I don't really store it longer than a day though.

 

[user 4295]

I received an answer to this question a long time ago in an email from the owner of Five Star Chemicals. He said that the only factor that really mattered in its effectiveness is the pH. It needs to be below 3.0 pH. Even if the solution rises above 3.0, it can be "sweetened" back up by adding some more concentrate to the solution.

He also stated that the solution becoming cloudy was not an indication that the solution had lost its effectiveness. It was only an indication that the water used to make the solution had a lot of dissolved minerals in it. Those dissolved minerals cause the pH to rise, but again, that is taken care of by adding some more concentrate to drive the pH back down.

Cloudiness can also be caused by organic matter getting into the solution. That would be due to insufficient cleaning of the equipment before sanitizing. I've kept Star-San solution for months without any loss in its effectiveness. Low pH and keeping out organic material are everything.