It's perfectly normal for a bottle to be brighter in color, hotter, milder, less or more garlicky - it's the nature of a natural product made from produce!
Growing conditions change all the time - days of sunlight, how much rain fell that season, if wind stressed the plants, all these factors change the produce. Every now and then the onions you're cutting just seem extra strong, right? It's not in your head, that's an extra flavourful and potent bag of onions, likely from the same supplier as last time.
Common variances are:
Heat Level of peppers
Depth of color in peppers
Fleshiness of peppers (affects sauce thickness even if same weight is added to recipe)
Potency of garlic, onion
Sweetness of carrots, onions, peppers, berries
We understand that our customers want the exact same sauce they loved last time, and strive to achieve it. We do our very best, but also embrace the variance in beautiful natural produce that we create our sauces with - it's part of the exciting world of flavours and food!