Scotch & Abram's Irish Breakfast Tea

A tasty blend for sure

I have probably drunk a dozen loose-leaf blends called Irish Breakfast. The S&A blend is among the most nuanced as to good, strong body plus sweet aroma and flavors. No artificial additives as far as I can tell, maybe a nice Ceylon and/or Keemun black tea along w a decent Assam. How do the blenders of this product maintain the same effect through different production batches?