How reliable are the pH strips you can buy in homebrew shops (don't have a brand name handy, sorry)? I bought a pack but the readings I get just seem way off. My city's water department reports our pH as about 8 at the tap (granted this was last published in 2009) but my pH strips read something nutty like 5 at room temp. There's just no way tap water would come out at a pH of 5, right? It would taste like lemon juice.
My mash pH after cooling to room temp routinely comes out at sub-5 according to these strips. I was worried, but after the weird plain tap water results I think the strips just suck. I am getting awful mash efficiency (sub 60%) which is why I started measuring this shit. What do you think, BN Army?
...not very reliable. Get yourself a good PH meter and learn to calibrate and use it. It will improve your brewing immensely. It's also useful for discerning when your starsan is no longer useful.
You can get a nice meter for around $100 or so. Do a search here or at homebrewtalk.com. Milwaukee and Hanna are popular brands. I have one of each and don't find any appreciable difference, but the Milwaukee has a bigger display which is easier on my old eyes.
Once you have it, you can perform test mashes, and measure your PH levels through the entire brewing process. You'll gain a ton of insight for a relatively modest outlay. Much more informative IMO than dicking around with spreadsheets. I've even taken my meter to homebrew comps to find correlations between winning entries and PH. Interesting stuff!
Brew on brother!