Take a look into the sherry making process if you can find a good resource. The (highly generalised) idea is to use several batches created yearly say, so that by the time you have made seven batches for example, the first batch is fully matured. You siphon off half of the first batch and this is your starter - it tells you the character of the finished product, but only really hints at what you'll get. Now you take each batch and tow it down the line, taking half the second batch and topping up the first and so on until you are left to top up your most immature batch. By the time you've got this working as a production line the consistency of the final product will be pretty solid. Personally I can't stand sherry, though.
I'm at work and don't have access to my brewing books so I can't be any more specific than this but I found it an interesting solution to the problem of consistency.
It's referred to as a Solera, and it's more for making a product consistent over a timespan of years. Non-vintage champagne is also blended together for consistency. As is scotch (even the single malts are usually blends of multiple years). The Solera is slightly different in that the wine is commingled over the course of years, whereas in most champagne and whiskey production the blending is done just before bottling. Some beers that are aged are blended (rodenbach comes to mind), and even Budweiser gets blended together from different tanks to ensure the end result is consistently "Budweiser".
That's exactly it, cheers for that - the brewing book I use mentions it's a traditional method but seems to imply for Sherry, but maybe I'm just not remembering correctly. Thanks for clearing it up. I'm in half a mind to set one up for my elderflower champagne (the hard stuff ~16%ABV). But this year I'm just going to focus on method and produce as many small batches as I can.
I'm at work and don't have access to my brewing books so I can't be any more specific than this but I found it an interesting solution to the problem of consistency.