Many Homebrewers who enter the microbrewing scene may believe that all they have to do to be successful is replicate their home brewing systems and recipes on a larger scale. But is this folly? What issues must one consider to avoid any traps, if any?
When I volunteered to be a judge at the VicBrew homebrewing competition some years ago I was expecting variable beers at best.
Being on the judging panel (with 2 other judges) for APA I quickly found that the level of beers presented were quite good.
However, I did pick out a common trait with many of the beers I tasted and that was the “aged” character in many of the beers. My fellow judges did not necessarily pick this trait in any beer.
It was though this fault was so common in homebrewed beers that many judges just do not pick it as a fault. One of the methods to finding “aged” beers is by the lack of freshness of some of the obvious flavours such as hops, fruitiness and even maltiness.
Although this lack of flavour may be subtle, it is compounded by the presence of a papery flavour development know as Trans-2-nonenal.
What causes this flavour is oxidation of beer that generally occurs by the filling of bottles without regard to eliminating oxygen from this process.
So what has this to do with scaling up to microbrewing volumes?
This an example in the process that may be different in large scale brewing because of the reasonable reduction of oxygen found in bottling systems in breweries.
Not that it doesn’t happen in breweries as well, just that it’s probably more prevalent in homebrewing due to lack of appropriate methods and equipment.
So, in breweries, the flavour may actually be fresher for longer and not suffer the effects as described above.
There are many more scale up factors that will determine the final flavour profile of a microbrewed beer which will be different to homebrewerd beer, even if exactly the same proportion of ingredients are used.
These could include;
- yeast hydostatic pressure (pressure derrived from large volumes of beer) which determine the fruitiness of beer
- the size and shape of the fermenter
- brewhouse configurations which determine efficiencies that may determine the amount and quality of the wort and consequently the beer
- quality of water
- more accurate temperature control in the brewhouse, fermenters and final product
- Better monitoring instrumentation and QC control in microbreweries
- Clarification and filtration techniques used
And many other factors.
In general, I find that brewery beer is more consistent than homebrew because there is generally more control systems available and the brewer uses a degree of procedural knowledge that allows less variation in the final product.
So not only the choice of equipment but the procedural knowledge of the brewer can have a dramatic effect on the flavour profile and consistency of the final beer.
And then there is the shelf life of the beer. We mentioned above that the flavour profile can change dramatically over a period of time so the microbrewer seeks out ways to limit this deterioration of flavour, or aging.
This can be a defining aspect for a microbrewer and what can set him apart. Even in homebrewing there are steps you can take to minimise flavour deterioration.
Professor Charlie Bamforth, from UC Davis, explains well what homebrewers and microbrewers need to do to delay onset of aging.
Surprisingly, many brewers think that it is in the brewhouse they must limit the introduction of oxygen but according to Bamforth this is not case.
To learn more about these issues and flavour deterioration you can attend brewing courses such as those provided by Costanzo Brewing or give Vince a call to discuss your particular issue.
And if you are contemplating starting your own microbrewery you can also download the complimentary paper on ” The 12 Step Checklist to Preparing to Start your own Microbrewery”
P.S the next course series will be in the once a year series in Perth starting 21st June 2014. So don’t miss out.