That’s so deep man. 8)
If you are hung up on whirlflock as final say on beer quality you really are missing the point.
I build my recipes on software but prefer to round things off to the nearest 1/4 pound, except for color grains then they are rounded off to nearest ounce. I weigh on a dial scale that is probably accurate to +/- 2 ounces. I mill it as tight as I can without stopping the rollers. I build my water using salts weighed to the nearest gram, and acids to the nearest 1/2 ml. I heat my strike water to nearest whole degree. If my mash temp drops four degrees I’ll heat it back up. I time my boils. I usually take an OG reading. I don’t count yeast cells. I pitch active starters, rather than measure cell counts. I chill to at or below pitching temp. I ferment in dual stage temp controlled chest freezer, normally within a degree or two of target temp, measured off actual beer temp. I force carb based on temp and pressure, but I dont measure actual volumes of co2. I usually measure ph with a meter thats only good +/- .2 ph. I measure ph all the way through on new recipes, but only final ph on repeats.
To me, my method is not meticulously OCD, and not sloppy. Somewhere in the middle.
Yes, you (read: “I” in this case) can taste a difference. That is why I am anal about my own brewing. If I didn’t think it was worth it, I wouldn’t be so particular about it. Logic checks, right guys? Ha.
And no, I haven’t done a blind triangle. 
I don’t doubt the anal approach (what did I just say there?) but I am kind of playing devil’s advocate and defending my own approach at the same time. I think that people were making consistently good beer well before a hydrometer or the ph scale existed. Once familiar with the measurements and procedures one can do it your own way.
The thermometer is probably the greatest equalizer in brewing. Revolutionary.
I brew for my taste, but the test I have, known only to myself and my wife, is this: When family and friends come over I show them the taps I have brewed and a well stocked beer fridge. I am successful when they choose my beer over the commercial stuff. Only recently have I been successful in this regard.
If they could be, they wouldn’t be the same beer.
I do all this stuff and consider myself pretty casual. As Keith says, making beer ain’t hard.
right there with you Steve
Leave out a whirlfloc tablet? Not a big deal. fermenting a lager at 75°F? Maybe a little bigger deal… As are a number of other things that were mentioned previously. pH, mash temps, water profiles, etc… Ignore these and, as said previously, you can still make ok beer. Pay proper attention to them, and I guarantee you will taste the difference.
It’s not that one totally ignores all things, some things for sure, but it’s that they’re not done to the same level of detail.
An easy test is give two different brewers one recipe (say Denny Conns Wrye Smile IPA).
When all is said and done can other people identity both end products as Denny Conns Wrye Smile IPA (of course all tasters would need one from the man himself first and then asked if the others closely resemble the first, i.e. are they the same beer)?
An interesting juxtaposition.
Too much emphasis is given to ingredients, and not enough is given to process.
My club has done a couple of activities where a recipe was decided on, and ingredients were purchased and then split in to “kits”. So everyone got the same malts and hops weighed out, and used the same yeast. Variables were water, equipment and process. The results were judged using a panel and BJCP score sheets.
The results were from the low 20s to the low 40s. Roughly a 20 point spread, I don’t remember the exact numbers.
If anyone wants to try this it is a fun activity, and a learning experience for club members.
An interesting exercise Hops and Malts.
Well sure, everyone knew the ingredients were the same, but if the tasters are blind (not told that it’s suppose to be the same, then asked if it is…)
Try it.
So what I got from Jeff’s answer based on the “activity”, is an implied No to the original question?
But if the only variable were the brewer(s) and all other factors somehow remained the same the replication would be closer IMO. In the club study the recipe is the only variable that didn’t change. Everything else did so it is to be expected the beers would vary in such a wide degree.
The ingredients didn’t change, except for the water.
The recipe changed, as each Brewer used their equipment and process.
rec·i·pe
ˈresəˌpē/
noun
noun: recipe; plural noun: recipes
a set of instructions for preparing a particular dish, including a list of the ingredients required.
“a traditional Indonesian recipe”
synonyms: cooking instructions/directions; archaicreceipt
“a tasty recipe”
Either none, almost none, or a lot. I am extremely accurate in weights and measures, but I still skip a lot of other stuff I find unnecessary. Your questions is way too braod. You assume that those minor differences will make a difference to the beer, and I don’t think they necessarily will.
In that experiment the only significant variable should be the brewer and particularly the brewer’s meticulousness with their process. The basic brewing equipment should not produce that different of beer across different five gallon systems especially if those systems are dialed in well by the brewer, which goes to the brewer’s meticulousness. Minor equipment may vary more (e.g. measurement equipment) but again that really goes to the brewer’s meticulousness and significance put on the details. Even the brewer’s choice in water is a factor closely related to the brewer’s own meticulousness and skill.
Well if a “recipe” was “decided upon” then the brewers needed to brew (process) within set parameters. But if the process was left up to the brewer then they just received “ingredients” not a recipe at all- and decided on their own how it was to be prepared.
In regards to the OP I proposed the theoretical scenario where only the brewer changes and the playing field is level. They use the same familiar equipment, water, ingredients and method and provided instructions with a defined goal. One cuts corners- the other doesn’t. My opinion is the resulting beer will pretty close. On different systems all bets are off.