Let's get all the details on the Anchor Steam clone as an example to troubleshoot. Walk through your entire process in order from the start. We can try to figure this out!
Okay here was my brew day:
Batch Size: 3.5 gallons
Water: 5 gallons of local tap water treated with 1/4 tablet of campden
CA: 52.3 ppm
MG: 13.8 ppm
NA: 18.1 ppm
SO4: 74
CL: 61.7
Bicarbonate: 74
Grain Bill:
5.6 lbs - 2 row
8 oz - crystal 40
8 oz - crystal 60
Hops:
15g Northern Brewer (8% AA) 60 min
15g Northern Brewer (8% AA) 20 min
Yeast:
1 packet of Mangrove Jack M54
SG: 1.059
FG: 1.015
I washed my 7.5 gallon brew kettle with PBW. I prepared a half gallon of boiling water and added my brewing salts and campden tablet. I initially mashed in with only 3 gallons of water to try and create a "thicker" mash to battle the high pH values I was getting. However, the pH was very low at about 4.6, so I added the remaining 2 gallons of water and the pH stabilized to about 5.2.
I mashed at around 150-152 for an hour. I had to stir and manually raise the temp a few times with my gas burner. After that, I drained the mesh bag and squeezed out the remaining wort. I do like to extract as much wort as I can because people have advised me that I can't extract tannins with my hands.
I started the boil and added my FWH of 15g of Northern Brewer in a muslin bag, and then another 15g at 20 minutes. I forgot to add my yeast nutrient and whirlfloc tablet. At 15 minutes, I put in my copper immersion chiller, then started to cool the wort down.
I did notice that I did not add enough water and overshot my SG, as it came out to 1.061, when it was supposed to be 1.052.
I took my temperature readings and got the wort chilled down to about 70 degrees after 15-20 minutes. I let the wort sit for another 15 minutes to try and let the trub settle. Then I got my rehydrated yeast ready during that downtime. Once the wort was reading 70 degrees, I pitched the packet of yeast into the carboy.
I did try something new on this batch in particular. I used a carboy cap and stainless steel thermowell to try and read the internal temp, but I ended up creating a bad seal with the carboy cap and noticed that during primary fermentation, the CO2 from the yeast was not bubbling in the airlock. So there was definitely a bad seal.
Fermented at 65-68 degrees for 5 days before racking the beer to my keg. Despite the bad seal, the yeast tore through the batch and the FG was 1.015.
I transferred the beer using an auto siphon directly into my CO2 purged keg and cold crashed over the next 2 days and then fined with gelatin. I hit it with 15 psi of gas for 2 days and it's looking nice. I will upload a picture tomorrow. The head retention is pretty good and color is spot on. It is a bit cloudy and appears to have a little chill haze.
I think I made some mistakes along the way, such as not oxygenating my wort nearly enough, not adding yeast nutrient and also trying the new carboy cap and having a bad seal. However, I'm not exactly sure if those would cause the off flavors.
I still suspect it has something to do with pH because this off-flavor has been present in nearly every batch.