View Full Version : sterile bottling

02-21-2005, 10:05 PM
hi all,

There are some great suggestions and threads on bottle conditioning and discussed in detail. Instead of bottle conditioning is it possible to successfully sterile filter (0.45um, after DE and Trap filter) and bottle beer with a decent shelf-life? (3 - 6 months). I know it is possible for lage scale, but what are most micros and brewpubs doing when they fill with a bottle-filler similar to a Meheen??
I am looking at starting modestly with about 5000 bottles per month and storing at refrigeration temperatures.
How big an impact will sterile filtering have on head-retention?

I appreciate any advice.



03-06-2005, 09:26 PM
No opinions / advice on small-scale sterile bottling????

03-07-2005, 08:47 AM
We D.E. and then sterlie sheet filter our products. The packaging is not really "sterile". For sterile packaging w/o pasteurization I think you really need a positive pressure sterile room w/ sterile filtered air supply (only macros can afford). After we filtered we carbonated in a bbt and we would bottle as cleanly as possible (lot of micros do it this way with no major probs.). We used to use a meheen and you will definitely notice a flavor change at the 3 month mark. Do you think your product will sit for three months? How about using some preservatives? If you want to see what your beer will taste like go to a brewery that uses a meheen and perform a flavor stability test: shake for 1 day to mimic transport, store 4 days in dark 40C room (=shelf life of 3 to 4 months), then taste. We never have any probs with head retention. So yes, you can package with DE, sterlie sheet and then a meheen but I think 6 months shelf life is way to optimistic.....maybe 3 months max? I hope this helps a little.

Rob Creighton
03-07-2005, 05:11 PM
We have sterile filtered (.45 absolute) in small breweries for decades without significant issues. I have used vertical and horizontal screen filters, stacked disc meta-filters, shell & tube filters and plate & frame sheet filters for DE filtration (and rarely used a trap filter) and generally followed with sterile cartridges prior to the filler though I have used a Seitz DE plate and frame followed by a crossover plate through sterile sheets as well.

It is simply a question of filtration fundementals and proper sizing. Do you use a trap filter because you don't set up and follow proper technique with your DE filter? Are your staff properly trained? Does a trap really do anything? A large brewery up here used disc meta-filters because the head brewer pioneered the technology in the '50's. They spent a bizzillion dollars putting sterile cartridge set-ups in line with their filler only to realize that the blow through from this out-dated technology was high and they blinded the steriles in minutes. At $1800.00 per changeover it was an expensive lesson which they solved by putting in an expensive SS bypass - go figure.

I want to be confident my DE filtration is doing what it supposed to do and my sterile filtration is also doing its job to spec. I want these facts to be measureable (under a microscope). I don't expect any CO2 change because that would mean the filtration system is causing breakout on route - this shouldn't happen. I don't expect any colour or flavour loss but greater taste buds than mine may argue this. I have never noticed any difference in blind tastings.

We spend a lot of time sanitizing our line set-ups, our filters, filling equipment, bottling hall, bottles, etc... I have never used a sterile room for filling. The results show up at the outlet of the capper - remember that the capper is the #1 source of package contamination on sterile lines. We ensure that our BBT tank airs are zero prior to bottling which is the main reason craft brewers usually blame fillers for high air product IMO.

I think you use common sense as well as cleaning and operating fundementals and then you make sure your results are verifiable. This applies to a brewpub using a single head filler as much as a 300 bpm line. The principles don't change, just the equipment.

Use shelf tests and that sophisticated tasting apparatus between your teeth to tell you if you're going the right direction. I loved arguing with Dave Meheen about having access to his programmable controller on the filler because I am the brewer and I will set the packaging specs for my product!

In the end relax and drink one of your own brews. Cheers!

03-08-2005, 02:31 AM
Thanks guys,

great advice, very informative and encouraging.