After beer has been brewed; that is, sugar has been extracted from grain, the resulting sugary liquid (wort) has been boiled, and then yeast has been added and fermentation has taken place, the result is essentialy beer. One ingredient is missing, however; carbonation.
This is a favorite element of beer, not only making it quite drinkable (speaking here of the light and refreshing feel in one’s mouth) but enhancing the aroma and flavor. But how is beer carbonated? Like many things in life, consumers often take this for granted. A few curious beer drinkers have asked me–being a home brewer–how I carbonate my beer. Most are clueless. One individual guessed that I added carbonated water to my fermented wort. This isn’t the case. Typically, there are two methods for carbonation: forced and natural.
Forced carbonation inserts the CO2 into the beer. The beer is place into a sealed (or soon to be sealed) container and carbonation is rapidly added. Under high pressure, the CO2 is absorbed into the beer. This is actually the preferred method for most breweries, as the turn around time for a finished beer is quicker, and the bottle contains little to no sediment, as the beer has been pasteurized and yeast removed from the liquid.
Natural carbonation allows yeast to remain in the beer. Sugar is then added to the beer in its container and then sealed. Fermentation kicks off again as the yeast eats the new sugar addition. When yeast ferments, it releases CO2 which is then absorbed into the liquid? So which is better? How are they different?
For the greater part of my tenure as a home brewer I relied on natural carbonation, as I didn’t have a kegging system to force carbonate my beer; I would rather spend my money on beer ingredients than the costly upgrade to kegging equipment. This past Christmas, my dad surprised my with kegging equipment and the opportunity for forced carbonation. As an experiment, I brewed two nearly identical batched of beer and carbonated them differently for comparison.
There is a marked difference.
The force carbonated beer looks better. The bottom of the bottle boasts no sediment, and the beer pours crystal clear. It looks like it was pulled right out of a sixpack from your typical craft brewery. It pours with a decent head and bubbles cling to the inside of the glass. Lacing is minimal.
The beer carbonated ye old naturale method has a thin layer of yeast on the bottom. The head is thicker and more billowy with more peaks and valleys, and it has longer retention with more lacing. There are fewer bubbles sticking to the glass (both dishwasher cleaned) and the bubbles are tinier. In the mouth, the beer feels smoother than the force carbonated beer, and more effervescent; perhaps more champagne like, though both feel as they have the same level of carbonation. The beer that was carbonated induces more belching.
Flavor? Yes, there is a difference.
The beer that was carbonated naturally has a slight yeast bite. It is a bit more bready; an attribute many homebrewers avoid. I myself enjoy it. The naturally fruity (no fruit was used in the making of this beer) qualities of the Belgian yeast strain are much more prominent and there is an overall level of complexity not attained to by the beer that was carbonated by force.
Admittedly, I am just scratching the surface of this complex topic, but so far, I prefer natural carbonation (sometimes referred to as refermentation). I intend on repeating this experiment repeatedly and am aware that there are more complex and specialized pieces of equipment for better forced carbonation, and also realize that my beer that was force carbonated had not been rid of residual yeast.
Home brewers and pro brewers, what are your thoughts? Non brewers who just love beer, what are your thoughts?
This is a great topic Nate. I think I prefer the natural over the forced, but really it isn’t clear when you are drinking a craft brew which method was used. I assume I have had some really great beers that have been carbonated both ways. I’m certain that when I actually do start brewing I will use the natural carbonation, but it is interesting to consider from a financial point of view whether forced carbonation makes beer more profitable and easier to produce without having to bottle conditiona a lot of beer for a long time and have to have the space etc. to give to the bottle conditioning process, etc. I’m sure you will have to make this call a lot oince you open your brewery!
I prefer to force carb simply because I have more control over the carbonation. It is also faster ad easier.
I’m with you an turn around time. Being able to drink a beer 48hours after kegging is great. I have pretty good control over carbonating naturally, but i did make mistakes at first.
What about Flavour/Complexity?
I too have had excellent beers both ways. You know, Boulevard brewery naturally carbonates every brew, claiming superior flavor.
Look for the yeast at the bottom. That’s the simplest way to tell.
i know this might be a cop out, but i think it’s less of a natural vs. forced issue and more an issue of when are they appropriate (per beer style, abv, complexity, etc.)
I’m only saying this because as I read the post, I recall watching a video where Allagash’s Rob Todd explains how they still condition all Allagash White, because not matter what the technique, a force carbonation altered the flavor to drastically. That being said, IIRC, they force carbonate the rest of their kegged beer and some of their bottled beer. I could be wrong though.
That’s a great point, hokie. the beer that i “experimented” with was a Rogenbier…bottle conditioning is quite important. Like I mentioned above, Boulevard bottle conditions everything from their Zon to their IPA to their American Wheat. Admittedly, they aren’t the norm, though.
Oh yeah, Hokie…I like your website. i wish I was better at web stuff, html, php, etc.
Last week I kegged my first keg ever and was going to force carb. I checked my co2 tank and found out it was empty. I ran to the homebrew shop and started talking to the owner. He told me to cut my regular bottling suger in half and add it to the keg just like I was bottling. Hook up the co2 tank to pressurize it and let all the air out. Unhook the tank and let it set 1 to 2 weeks. He said I would save on co2 this way. Have you ever heard of doing it this way?
Steve…Yeah, I have done it too, using only a third of the normal sugar. The first draw pulls some of the settled yeast, but after that it runs clear. I think it tasted great, and had an amazing head.
I also use both and can’t say I have a real preference. I think another important thing to think about is the style of beer and whether it can be aged. I tend to keg and force carb my more everyday drinking and sessionable beers while bottle conditioning higher alcohol stuff, my belgian-styles in particular.
Belgians and German style beers, especially hefes seem like you should legally have to do the bottle conditioning. I think you may be right about some of the everyday beers. Still, even the MBAA handbook talks about bottle conditioning being the most character adding method. I think Nate and I both have a preference for bottle conditioning because of the extra character and fineness add to the beer. Of course, there are some great force carbonated beers, so I don’t want to take away from them.
Thanks for stopping in Ray. I’m glad you left a comment and we hope to see you back…maybe even a follow-up to what I said.
I haven’t done any side by side studies like Nate but I do think bottle-conditioned beers often taste better especially with a beer and a yeast that change with age, more often than not I even keg-condition with sugar. The speed and convenience of force-carbing is tough to beat sometimes though.
Definitely agreed on how gratifyingly quick the forced co2 is.
Im new to the homebrew. I am 2 batches in. After the second batch, I became concerned with natural carbonation. The two batches have a predominant flavor in each of them which is quite similar. I believe that I am tasting the dextrose. Now I would like to try forced carbonation on at least one of the the two recipes to see how the outcome differs. I would like to force bottle carbonation, but that seems like a chore. I think I heard about a co2 pill that you put in each bottle. Does anyone know what that is? Maybe I heard wrong. The two batches where a wheat beer and an american amber – both extract.
February 27th, 2011 at 9:47 am
First let me congratulate you on homebrewing…I love it.
As far as the taste you are getting, I’m not too sure it’s the dextrose. Maybe it could be but I’ve never had issues with it. The questions to ask are: what style of beer was it (you already answered but the I’d be interested to know the flavor you are getting)? Did you get a full and right length boil? What was your fermentation temp?
The second question has a good amount of meaning because a good boil drives of DMS which give a cornish flavor to the beer. Extracts need a solid 60 min boil. What was your flavor? Sometimes fermentation temp can cause issues. Lots of apple tones at higher temps with some beers. At any rate, I think there are a few more important questions to ask before the dextrose.
However, force carbonation is a good way to get it evenly carbonated. It’s a bit expensive to get the initial equipment.
As far as those pills are concerned…yes they do exist. The idea of them is more associated with proper levels of carbonation. Basically, you choose how many of them to put in each bottle, which gives you the levels of CO2 you want. However, they are basically just concentrated sugar and I’ve heard several reports of off flavors, which doesn’t really solve your issue.
I would look at the other issues first. However, if you get the same result, try using Malt extract to carbonate. Typically, you will need 1 1/4 cup of light malt extract to equal the same sugar (and therefore CO2) as you would with 3/4 cup dextrose.
Hope this helps.
I feel confident that the boil was long enough on both brews. I do think that I turned down the temp to a less violent boil to keep from boil overs on both brews. I did do the boils quite differently on each brew. The first was a 2.5 to 3 gallon boil and the second one I did with two 2.5 gallon simultaneous boils, dividing ingredient equally between the two. I got that idea from a “brew your own” article. I think they referred to it as a “Texas Two Step”.
Could it have something to do with the length of time it takes to cool the wort after the boil? I feel like I may have been a little slow with both brews. I did not use any kind of wort chillerj, and I only used cold tap water in the sink – no ice. I did repeatedly drain and refill the cold water bath. Both batches were cooled to fermentation temperature in about 15 min.
Could it be that I am refrigerating the bottled beer too soon? I tasted the first batch (wheat) at 1 week – still flat. I tasted it again at 2 weeks and was pleased with the carbonation level, so I gave most of it away to be a good sharer and refrigerated the rest. – I should have kept some out for another week. I still have plenty of the second batch to experiment with.
Could it be the yeast? I did use the exact same type of yeast in both batches.
The fermentation was quite different on each batch as well. The first batch(wheat) was fermented at a much lower temp than the second batch (American Amber). I fermented the wheat in my basement where temp was about 55F. I didn’t realize the temp was that cool until fermentation was complete, and I believe that because of the low temp., the fermentation took much longer than batch two – Batch one fermentation took 3 weeks. The amber was fermented at normal room temp of 72F. It was done fermenting in about 4 days. I did leave it for an extra 4-5 days before bottling. Both batches were switched to secondary fermentation at about 3 days.
I think that the reason I am linking the taste to the dextrose is that I tasted the dextrose out of the bag and to me the flavor I am getting is similar to that of the dextrose.
I had decided that I would force carbonate my next brews, but it seems that there are a lot of advocates of bottle priming, and I havent read anything that says that bottle priming causes a sweeter, dextrose-like taste. This leads me to believe, and as you have suggested, that the taste is coming from somewhere else.
Thanks for your response. It was helpful. I now know that the pills I was thinking about are sugar based. So, it serves me no diagnostic benefit to use those. Let me know if you have any thoughts after seeing the additional information about the brews.
February 27th, 2011 at 3:03 pm
Sounds like you did it all correctly. You boil was long enough, your cooled it in plenty of time (most people recommend 20 mins or less), the fact the you put it in the fridge was would only slow the maturation and should not ultimately effect the taste. As far as the yeast, it could be possible that the yeast left quite a bit of dextrine content in the beer (but those would mostly be malt dextrines) or could have an an effect on the flavor profile. Maybe a higher attenuating strain could change some of those tones.
Your temps were actually very good. The wheat temp is right on target and the amber is as well. It sounds like you have really covered your bases and have really made it a point to educate and inform yourself, so it’s going to sound silly when I ask you if you boiled the dextrose with water or added it directly to the beer. I’m assuming you did the former but I still had to ask.
My only other thought I have is to use malt sugar to prime. If you find that you are tasting the dextrose after all the other trouble shooting, it may be that you are particularly sensitive to the flavor (you are not alone in that either). You may find that buying an extra pound of wheat malt or light pilsen malt may work for you. The other solution I propose is to buy a little bit more or some specialty grain for steeping at the beginning of the brew to build the flavor profile up a bit more.
Let me know if I can be of any more help.
Thanks, your advice has been extremely helpful. — I did boil the dextrose on both brews. I think I boiled the first batch too long. I actually boiled it down to a thick syrup. I was cautious not to do that with the second batch. I will let you know if I figure anything else out. Thanks again for your advice. I will try the malt sugar, and I may go ahead and try the forced carbonation.
michael reinhardt Reply:
February 28th, 2011 at 11:16 am
You are more than welcome. You seriously don’t know how much I wish I could have had someone to advise on some aspects of brewing when I was starting out. Let me assure that it was my pleasure to give any advice I could.
Natural carbonation is a lot better. I believe a lot of the taste is lost, when you force carbonate.
michael reinhardt Reply:
June 15th, 2011 at 10:22 am
I prefer it too. I like the extra bit of character I get from it.
I sold all of my kegging equipment, mainly a space thing…but, I like bottle conditioning. A lot of the beer styles I brew work best with bottle conditioning. Yeah there is convenience in not messing with bottles.
I like bottles as well. More work but worth it for sure.
The problem with natural carbonation from my experience is so many bottles come out pretty flat. Maybe I am not cleaning all my bottles as well as I should but after brewing around ten batches now I have discovered that around half of my brews end up being pretty flat. The fermentation science majors at Oregon State tend to prefer forced carbonation for a more reliable head.
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