Keep in mind that those retail-priced $25 commercial wines also cost $5 or less for the winery to make (plus overhead, of course). While considering how great some of the commercial wines are, also don't forget the number of "meh" wines you've bought off the shelves. My $0.02 for the things that differentiate amateur vs. commercial wines, in rough order of importance: Knowledge of proper winemaking techniques. (Serious winemakers like @NorCal clearly have this one down) Proper dosage of ingredients based on the volume you working with. Knowing what to do and when to do it (pressing, nutrients, oxygen elimination, etc...) Knowing how to quickly spot and resolve issues (H2S, astringency, too hot/cold, etc...) Record keeping Experience in managing the wide variety of grape chemistry you get year to year and vineyard to vineyard Close relationships with vineyards to ensure quality fruit is picked at the desired time Cleaning and sanitation protocols Having quality equipment (this is where more space and money go than most amateurs have to play with) Stainless vessels & oak barrels vs. Brute trash cans & oak chips Pumps, presses, filters, bottling equipment that efficiently process the wine while minimizing oxygen exposure Lab equipment and the knowledge of using it to measure pH, TA, SO2, brix, etc... Temperature control Inert gas sparging Separation of production and aging spaces with their own environmental controls Volume and breadth of production (This is where it is hard for amateurs to compete with the scale of commercial operations) Large batch sizes in large tanks ensures uniformity and minimizes oxygen exposure Large variety of batches allows for blending out faults and insufficiencies while blending in complexity and depth to the wine Having known many winemakers around here, once you get them talking candidly they will gripe about how their own batches turned out also. You will always be your own worst critic. Complacency will never improve your wine, so we all strive to critique and improve what we do. Keep on brewing.