Pasteurization, Why, or Why not?

[MT2sum]

Recently I had a conversation with a local brewer, who just recently graduated and was certified by a College in Knoxville, TN. He told me that some of the larger imported brews, such as Guiness, etc. pasteurize their brews to extend shelf life, among other things. He said you would have to put your bottled beer into a pot (like a canner) and heat the water to between 160°F to 180°F for an hour or so to pasteurize the beer in the bottle.

Here's my questions about pasteurizing, more on a home scale rather than commercially. If you are bottle conditioning, wouldn't that:
1. Kill all the yeast that's helping your beer to carbonate?
2. Cause a lot of sediment from the dead yeast?
3. Kill any carbonation that was already there?
4. Blow up the bottles from the heat and pressure?
5. Skunk the beer from the high heat?

So how do these big guys get away with it! I've searched this site, and there is no information about pasteurizing beer, so it most likely isn't done on a small scale, but nevertheless, it's an interesting thought if I wanted to save a beer for a few years, rather than a few months

 

[LibertyBrewer]

I posted this https://www.homebrewtalk.com/f32/easy-stove-top-pasteurizing-pics-193295/ on another thread about pasteurization last week. It's a good read.
Now to answer your questions:
1. Yes, but you would pasteurize your beer after carbonation has ceased.
2. Not really.
3. Nope, the carbonation has nowhere to go. The bottle is sealed.
4. Be careful.
5. Skunked beer comes from a reaction of riboflavin and light. It has nothing to do with heat.

 

[MT2sum]

Sorry, the search box on this site gave me a zero on any pasteurization, so that's why I asked the questions. Thanks for your quick response! I am reading a lot of threads right now and probably one of them is yours! I found those threads using Start Page (I try not to use Google )
Thanks again!

 

[DrunkleJon]

Recently I had a conversation with a local brewer, who just recently graduated and was certified by a College in Knoxville, TN. He told me that some of the larger imported brews, such as Guiness, etc. pasteurize their brews to extend shelf life, among other things. He said you would have to put your bottled beer into a pot (like a canner) and heat the water to between 160°F to 180°F for an hour or so to pasteurize the beer in the bottle.

Here's my questions about pasteurizing, more on a home scale rather than commercially. If you are bottle conditioning, wouldn't that:
1. Kill all the yeast that's helping your beer to carbonate?
2. Cause a lot of sediment from the dead yeast?
3. Kill any carbonation that was already there?
4. Blow up the bottles from the heat and pressure?
5. Skunk the beer from the high heat?

So how do these big guys get away with it! I've searched this site, and there is no information about pasteurizing beer, so it most likely isn't done on a small scale, but nevertheless, it's an interesting thought if I wanted to save a beer for a few years, rather than a few months

As said.
1 - Yes
2- Depends on when you kill them. You would have the same amount of yeast sediment
3- CO2 is there. It has nowhere to go
4 - Possibly. You want to go gently
5 - no, it may change some flavors because you are somewhat cooking the finished beer.

The big guys pasturize and filter the beer then force carbonate before packaging.
Weirdly enough I have always heard that leaving it live protects the beers better. The main reason for pasturizing for big breweries is for clarity and consistency rather than for longevity. Why else would they have Born on and best by dates?

 

[duboman]

I pasuerrize my back sweetened hard root beer, it takes only 15 minutes at 160oF.

Use a kettle deep enough to hold your bottles and still be able to cover, heat water to 160oF and place bottles gently into kettle, allow to sit 15-20 minutes with the lid on in case a bottle decides to blow (It's never happened to me but can). Remove bottles and allow to cool.

I've done this many times and have shipped the bottles to friends with no issues.

 

[MT2sum]

Weirdly enough I have always heard that leaving it live protects the beers better.
Why else would they have Born on and best by dates?

Interesting thoughts ..... Thanks for your response! I did hook up on the 110 page thread noted above, and even though it's about cider, it has re-enforced the answers I've been given here! I don't think I'll be pasteurizing too much of my beers, but it has answered a lot of questions, some questions I didn't even have until I went thru that thread LOL
I'm thinking about making a batch of cider now ..... I wonder what brought that on? .........
THX

 

[LibertyBrewer]

As said.
1 - Yes
2- Depends on when you kill them. You would have the same amount of yeast sediment
3- CO2 is there. It has nowhere to go
4 - Possibly. You want to go gently
5 - no, it may change some flavors because you are somewhat cooking the finished beer.

The big guys pasturize and filter the beer then force carbonate before packaging.
Weirdly enough I have always heard that leaving it live protects the beers better. The main reason for pasturizing for big breweries is for clarity and consistency rather than for longevity. Why else would they have Born on and best by dates?

You might want to check this thread out http://www.micromatic.com/draft-keg-beer-edu/beer-pasteurization-cid-1753.html According to them, one of the benefits of pasteurization is the ability to store beer at room temp. for up to 120 days. This is for can and bottle beers. Kegs that are pasteurized, can be stored 6-9 months.

 

[DrunkleJon]

You might want to check this thread out http://www.micromatic.com/draft-keg-beer-edu/beer-pasteurization-cid-1753.html According to them, one of the benefits of pasteurization is the ability to store beer at room temp. for up to 120 days. This is for can and bottle beers. Kegs that are pasteurized, can be stored 6-9 months.

True, pasturizing a beer pretty much freezes the beer where it is. Since no microorganisms are living in the beer, what you have is what you have. Leaving your beer live allows your beer to condition over time and develop. Aside from providing you with some nice probiotics, your brews will change over time. True, higher temperatures will cause the changes to occur more rapidly and there is the possiblity of the beer going downhill if set on the yeast too long. I have seen bottles of non-pasturized beer saying things such as "age up to 5 years" and longer.

In my opinion, and my above post was that as well, the pasturization of your average macrolager is done for clarity purposes with the filtering, as well as to help maintain their amazing consistency. The flavor of your average BMC is what they are shooting for and as a result, pasturization allows the product to remain at that point for longer. For your average home brew, unless you are back sweetening, accidentally over primed, or want to kill off the bacteria bugs so as to not overcarb or to mitigate an infection pasturization is not really necessary. Besides, most homebrew beers need that conditioning time. Ever notice that your beer is better in the 2nd month than it was just after week 2 of bottle carbing? Why else is the last bottle usually the best?

 

[peterj]

I actually heard an interview a while back with Charles Bamforth of UC Davis and he stated that a lot of the reactions that happen with long term aging are not yeast driven. They are just chemical reactions of various molecules in the beer that happen very slowly given enough time. That's why beers stored warmer will "age" faster because the rate of all chemical reactions increases as the heat increases. Though I'm sure a pasteurized beer would age differently than an unpasteurized one. The yeast likely play a role in aging.

 

[Shuznuts]

My take on this topic: of the beers that I ended up aging a significant amount of time, the factor that contributed most to long term flavor changes was O2 causing stalling reactions vs flavor taints caused by spoilage microorganisms. As an example, a sample aged over 9 months had less bittering characteristics and more "papery" off flavors caused by oxidized aldehydes. That being said, the temp increases in pasteurization would only speed up these stalling reactions and thus speed up the development of flavor instability. This has been my experience, while other folks might have a specific need for more microbiologic stability provided by pasteurization.


Sent from my iPhone using Home Brew

 

[JonM]

I'm not 100% certain the reason, but in torts class, the classic product safety example is the exploding Coke bottle. I'd bet pasteurization is to make darn sure that commercial beers have zero chance of becoming bottle bombs which --> bad press and lawsuits.

Miller beers always talk about how they're "cold filtered, never heat pasteurized." I think filtering out all the yeast is just another way to prevent bottle bombs in commercial beers.

 

[DrunkleJon]

yep. You filter fine enough nothing living gets through. Often neither does taste.

 

[MT2sum]

 

[dnslater]

My bottled homebrew ages just fine without pasteurizing. I usually store a few of my darker brews away. I opened a coffee stout this year from 2011 and it was terrific. Also tried a 2011 Fat Tire clone and it was nice. If you have good sanitation, I seen no benefit to pasteurizing.

 

[MT2sum]

My bottled homebrew ages just fine without pasteurizing. I usually store a few of my darker brews away. I opened a coffee stout this year from 2011 and it was terrific. Also tried a 2011 Fat Tire clone and it was nice. If you have good sanitation, I seen no benefit to pasteurizing.

Yeah, The only thing I pasteurize is soda pop and cider (can't keep them in the fridge)
I have yet to have a bottle bomb in any of my beers (except back 5 or 10 years ago!).