If you brew you know exactly what I mean . Yes of course you have a Solid lab there going to make every accurate dosed , sterile gear . And if you have worked with them for years and love there gear , service etc of course your going to stick with them 100 % , personally I find that if you make batches in the 1000ml range it's the best for quality control and obviously you have a recipe your lab equipment raw and your method . If you stick to the exact same protocol each time your going to be pretty on point with your gear , but there variables , your raw source some times you gotta switch up , some times it does come 99% .. then when your operating a lab for years and years and years , you eventually have a team working with / for you and yes the person hired to brew / label is doing everything there supposed to but unfortunately you get some bad apples along the way , just with any other kind of products. Some times people quit steal all your secrets and copy your brand and under dose the shit out of the gear and pump it out .. these are all very realistic reasons a batch might be fucked up.