If not stored properly over long periods of time can these strips go bad? I was out of brewing for a while and had my items stored in a shed that was subject to humidity and temp swings. Once I finally started brewing again and using the strips I kept getting the same color on the strips. Regardless of the beer color SRM ranging from straw yellow to dark brown the strips were still reading in the 5.0 to slightly lower range. I am using the same water from the same source with no adjustments and still getting the same reading. It got me thinking that improper storage may affect them, or they may have some sort of shelf life.
Do you use Star San? If so check it straight and diluted and see if there is a difference.
Or check some vinegar or something else in the house.
I think it’s very possible that they could “go bad” if stored improperly. I was clutzy and dropped a few out of the box and they fell into a bucket that had a few drops of water in it. I took those strips and put them off to the side in my beer closet and later noticed that the small pad on all of them were a different color than the “new” ones. I would think that storing them outside could make them inaccurate at the very least. I know where you’re going with this too… those things are expensive! Sorry Man.
Yeah that’s what I figured. You know what though, it’s kind a blessing in disguise. I use to be really into water chemistry and fretted over making sure I had just the right amount of this and that just to make sure the pH was perfect. Since I have been unable to tell the pH I’ve just used the water as is. I make some additions to ensure my water has the proper minerals, but not for pH. My efficiency has been just as good, if not better (which makes me truly think efficiency is more about crush than anything else), and I can taste absolutely no negative impact in my beer. Just goes to show me that, yes, the science part is cool but I am not way less concerned about it.