so I was taking to the sales manager for a local brewery and I was complaining to him about their ipa that was just delivered and put on the shelf at a shop was bottled in October. He told me that they use a centrifuge before packaging and that their IPA is good for 120 days. I told him I seriously doubted an IPA a week old vs 4 months old would be the same beer. I know we are home brewers and don't have access to a centrifuge but My question is Doesn't a centrifuge only serve to filter and clarify beer? The hop profile would still surely fall off regardless of using a centrifuge or not yes?
I don't think centrifuging would do anything to preserve hop flavor/aroma. If anything, it might remove some hops oils from suspension.
Yeah, like vikeman said I think that IPA starts losing hop character the minute they turn on the centrifuge. On top of that, no IPA in the world is as good at 4 months as it was fresh.
I know this is a simplistic response, but, intuitively, the hop oils wouldn't be removed by the centrifuge. Only the gunk that normally takes a few weeks to settle in the keg would be lost. But I'm not speaking as an expert.
I considered purchasing a centrifuge for my brewery... for about 30 seconds . I believe that the sheer force that is exerted on the beer is bad for the beer. A lot of centrifuges also have high oxygen pick up (although, a lot have been designed significantly better recently and no longer do so). It is possible to have great shelf-life for hop flavor if there is little oxygen pick up and some hop varieties are prone to longer lasting flavors. That said, if the brewer is claiming that the reason for their shelf life being 4 months is because of their centrifuge, I would assume that they don't know enough about brewing science to be trusted in their assessment.
Hop oils stick to yeast cell walls, I believe, so if you spin the yeast out, you will lose hop oils that are stuck to the cells. However, if the hop oils had not yet equilibratesd with the cells, maybe you are removing active surfaces that oils would have sorbed onto and settled out with.
All I can really think of using a centrifuge for is you really happen to like consistently clean appearing beer and have a tight schedule where you need to constantly turn your tanks tanks around to keep up with demand. i.e. You cannot afford to sit on a tank because whatever beer is not crashing out quick enough. I'm going to agree with VikeMan on this because the oils which are heavier will separate out of solution as the centrifuge does its thing. If this brewery is worth its salt, which I don't know because as Honkey alludes, talking about a centrifuge in relation to this particular topic and what you're asking from it is highly illogical.
Breweries such as Sierra Nevada and Russian River have centrifuges, their beers have hop aroma. Other parts of the process are important when you are after long shelf life, like low TPO, good crown seals and so on. Edit - sales manager...
You will not precipitate out the oils by centrifugation other that stuff like pweiss909 and mikehartigan mentioned sticking to yeast or some other glop. I would think those oils bound to such things would have precipitated out with the yeast or glop anyway so the additional centrifuge step still has no effect on oils. You can separate liquids into different layers by centrifugation but they must be highly phobic and done at very high speed and usually small volume, like 1.5-2ml range. Think of a typical DNA/RNA prep. Even if the hop oils separated they would be on top and just get mixed back in during transfer from the centrifuge. But to answer the OP I agree the centrifuge will not benefit the hop freshness. I think I remember a Brewing Network episode where Vinnie described a massive O2 pickup on Pliny when they first started using the centrifuge and had to do significant work to rectify that problem. Also, if I remember correctly the centrifuge was a solution to recovering the beer sucked up by the hops not to preserve freshness.
