Density separation in beer

No the bitterness is throughout the beer. But notice that your second pour has been exposed to more oxygen for a longer period of time. It probably also has lower carbonation, etc..

Edit: Also is it possible that there may be a temperature difference?

Edit: BTW, its also possible that your perception of the flavors was influenced by having had different foods on the two days. There is a carry over effect....

 

Here's your problem,
You need to shake it well before opening.
Make sure everything is mixed evenly

 

I've experienced what you're talking about but usually attribute it to solids settling at the bottom of the bottle - could be wrong though.

 

It's called oxidation. If you are saving half a beer for the next day it's going to get stale and flat. This will have a noticeable effect on the flavor. And no, " sealing them pretty well" doesn't help. The co2 escapes into the headspace, a half empty beer will lose most of its carbonation even if sealed, similar issues with O2. the only thing that is odd here is that you haven't noticed this before.

 

Yes. In two parts. Good beer (for the most part) handles better as it comes to ambient temp. i.e. Flavor country.
Also, yeast settles out, and there's another component of flavor in that sediment. If you want it through out. Take that bottle and relax the yeast by gently rolling it on a flat surface of your choice.

 

The second service was a lot colder than the first. The colder a beer, the more the flavor is masked. Also, salt masks the hop bitterness. So if you had something salty, like pretzels or chips, it won't seem as bitter.

 

In short - not surprising that the first half and the second half tasted different - multiple factors at play (many of which have been mentioned).

I cooked a steak, ate half and then ate the other half the next day after heating it back up in the oven. They tasted different.

 

Just drink a full 12 oz beer...

You must have extreme discipline I couldn't just drink half of a Founder's Imperial Stout...

 

Maybe you prefer that beer less carbonated and with more oxidation?

 

Next time, buy 2 12 oz. bottles, man up and drink an entire bottle at a sitting. This way, you'll be closer to comparing apples to apples, rather than comparing apples to oranges.

 

To much science for a guy who spent as much time in centerfield as Nebbie

 

what was temp of both? if you let 1 sit in bottle, them I can see why.

 

I second comments about oxidation.

I am a wine drinker as well, and it is a very common thing to 'open' big red wines over a number of days. Basically you are leaving the wine exposed to oxygen for longer and longer periods of time and this provides a facsimile of how a wine might age over decades in the sealed bottle.

Same thing is happening with beer - that is why I haven't even opened any of my founders imperial stout!! I bought a couple of 4 packs and slung most of them up the back of my cellar to wait 6 months to a year before drinking. I usually will get to one after 2 or 3 months, but more out of curiosity and impatience than preference for the 'fresh' flavors.

The exact opposite is happening with hoppy beers and drinking them fresh - however, I do sometimes prefer some IPAs with a few weeks of bottle age on them for flavors to settle down - really fresh (as in bottled that week) can be harsh

 

Based on what you say here and other places, I'm thinking that the primary source of difference is the oxidation between your first pour to having the second portion. When the beer is bottled the brewery takes great pains to minimize the amount of oxygen in the head space because that is one factor that leads eventually to staling. (All other things being equal, the more oxygen the more rapidly staling takes place. Indeed some suggest that the process of the beer going stale begins at the moment of bottling as a very small amount of oxygen is trapped in the head space to contribute to the aging of the beer even though CO2 is injected into the bottle before the beer goes in.)

When you've opened the bottle, poured, and then re-capped it there will be some loss of carbonation as the CO2 leaves the beer until the much larger head space is re-pressurized (happens all the time with carbonated beverages whether beer or sodas). However your pour and re-capping the beer also traps plain old air inside the bottle and that has lots more oxygen in it (both absolute and percentage amount) than even what was inside the bottle at the time of bottling. Even though you've refrigerated the beer from first pour to second all that oxygen will result in faster aging (staling) of the beer.

Also food eaten earlier in the day can have an effect on flavors you pick up from the beer. I've had two bottles from the same six pack taste different enough from one night to the next that I have no other choice but to implicate the effects of food earlier in the day. Especially since I began learning a lot more about pairing beer and food at mealtimes. Those two things interacting directly can make a huge difference in both.

 

Or just experiment! I have a few years of various things (ten fidy, founders impy, bells expedition) and am finding that I prefer different ones at different stages, and sometimes one year isn't as nice as another fresh, but is better with age! Also, I have found that I really like SN Bigfoot fresh, and with 3 years age, but in the middle (say 1 year old) it isn't my favorite - the fresh hops have faded, but the dried fruit and sherry notes you get with oxidation aren't coming through yet. All beers are different and even the same beer is different from year to year.

If you are not sure about a particular beer, then try one fresh, and leave half in the fridge with a stopper pressed into the bottle. I use a champagne cork thing to maintain some carbonation: http://www.amazon.com/gp/product/B0000TF4AM/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

I often pour the beer and let it sit for 20 minutes if it is a stout (so it warms up) and if I like it the 2nd day, I will stash the rest of the bottles I have for a few months and try another one!

It varies a lot even for very similar beers; at least for my preferences, but you will probably like different things at different ages! After a few experiments you will start noticing flavors in fresh beer that you think will be better with a bit of age.