Ferment and Cellaring

Here we are at the final stage of our beer in production. You boiled, cooled, aerated the wort and pitched the yeast, fermentation started and is cranking – now you wait, RIGHT?

Well savy brewers know what happens in fermentation results in the final beer taste and texture. Following your beer’s progression involves a few simple steps that can produce a mediocre beer or a superstar! When someone tries your beer they might say “this is good”. When someone tries your beer and says “WOW” now that’s a beer. You can make beers that show the difference between good and ones that are over the top.

All brewers can advance quickly. You can learn how to manage fermentation as you keep an eye on temperature. Preplan beer styles to match conditions, and choose fermentation areas. Know what stage primary is in so you can rack to secondary. Learn tricks to get a good “crash” so your beers are bright. Each step along the way you sample, taste, record stats, make decisions, adjustments if needed, do the final bottle or keg sit back and enjoy!

Throughout brewing you have expended alot of sweat and toil and all the time gained a building knowledge of how beer is made. By paying attention to key details our beers will display the most desired qualities found in any great homebrews or those which are professionally produced.

It’s been said before, the sky is the limit when you put your mind to it.

The best place to experience making beer is to visit a commercial brewery. While most homebrewers would love to do this it frequently winds up being out of reach. Finding out what they do and adapting it to your procedures can give your beer quality a great boost. The pros keep track of all the aspects involved in the process. They use temperature controlled tanks with thermometers and pressure gauges and sampling swickles, cleaned and sterilized hoses and pipes, and employ in-line heat exchangers and aeration. Well, we as homebrewers parallel their methods with equipment that can produce similar results. The tools needed to manage fermentation rests with our creative abilities to adapt and use whatever means within our reach.

At the brewery they focus on monitoring temperatures, testing gravities, pressure and carbonation.

Aroma, taste, body, and doneness are always carefully scrutinized. We don’t have the sophistication, but we can duplicate some of their techniques.

By employing their methods your beers will substantially improve.


  • Brew with the seasons
  • Winter creates areas of the house that retain a low 50’s temp so lagers are a great choice and treat
  • Spring allows for slightly warmer areas that are still cool enough to ferment a great California Common or Alt
  • Summer can mean trouble for brewing but might produce the best Wheat beer or Belgium Ale
  • Fall is great for just about any style of Ale
  • Wort aeration is key to healthy yeast
  • Use an aeration stone with pure oxygen and pre-charge the fermenter with the gas and allow it to slowly bubble into the wort as it fills into the fermenter
  • Pitch with plenty of yeast
  • Make a yeast starter especially for the higher gravity beers
  • Pitch two or three XL Wyeast paks or vials of White Labs – it costs more but will pay off in the long run
  • Refer to the pitch rate page on Wyeastlab website for temps, gravities and cell counts

Clean and sanitize

  • Always clean equipment soon after use to prevent hardening or caking of residue which becomes difficult to remove later on
  • Using sanitizers like Star-San on equipment prior to use will ensure protection from microbes
  • Always have a spray bottle of cheap vodka and afix a sprayer to a bottle of isopropyl alcohol
  • Use the vodka spray on surfaces that may contact wort or beer like stoppers or keg connectors
  • Use the isopropyl alcohol to mist the air above fermenters to provide a clean atmosphere before removing lids or stoppers

Watch your beer

  • Pay attention to the ferment at all stages noting dates and fermentation temps
  • Keep and eye on temperature to be sure it matches the yeast profile – use thermometer strips on carboys and move it to areas that are within the ideal range for the yeast

Transferring beer

  • Purge the sanitized secondary vessel with CO2 before racking beer into it to minimize oxidation
  • Before secondary to keg, fill the 5 Gal. corny keg with water and 1 oz. Star San and push out the solution with CO2 through a faucet on the out side. You now have a sanitized keg with no oxygen in it.

Temperature and Primary Fermentation

Conical fermentors are used commercially to adequately produce large volumes of beer needed to meet contract demands. Some homebrewers might have these while most use carboys, demi-johns,stainless steel kegs or corneys to ferment. Temperatures and gravities will be of most concern until kegging time when pressures will be addressed. The temperature at pitching is really important to setting the whole process of getting a true-to style brew. If you missed your target temperature work on getting to it’s proper mark. If it is too warm or too cool, carefully put the fermenter in a bath and slowly adjust the temperature. Slow additions of warm water or ice to the bath should do the trick. It’s a good idea to have one of those liquid crystal themometers stuck on (permenently) so you can always know and record temps. Have another location in mind being monitored and be ready to move your fermenter there if needed. Stay in the ideal range and remember that sometimes it gives you a wide berth. The German Alt yeast has an eleven degree range so midway temps offer a wide margin and will keep you close to the flavor profile. Upper end temperatures cause yeast to be very active thereby having a shorter fermentation time. This can produce more pronounced flavors in the fruity range whereas lower temps avoid certain products being formed.

While homebrewing I still ferment in carboys ( 6.5 Gal.) and always put on a blow-off tube after pitching directing it into a gallon jug of Star-San solution, which is usually left over from the brewday. At the breweries they use quatenerny ammonia in solution. Both inhibit microbial growth thus avoiding contamination. Monitor it if a large temperature drop can occur since the contraction may draw sanitizer up the tube into the carboy before the onset of fermentation. Fermentation will continue and then subside as the yeast begins to slow down. Replace the blow-off with an airlock as you see the foam declining. This is usually four days or more. Mist the top of the carboy by the stopper with a spray bottle of cheap vodka then mist the air above the carboy with isopropyl alcohol to sanitize the atmosphere. Now fit on your airlock and allow primary to continue.

Seems like ales up to a S.G. 1.050 ( 12.5 P ) finish primary in 7-10 days. Higher gravity ones can go two weeks or more till you see the ferment slowing to a crawl. The question usually is “when do I rack into the secondary?”. Well the best time is when primary is almost done so some yeast are still in suspension and some sugars still remain. This is because transferring beer usually involves some sort of aeration during the racking process. Any oxygen absorbed by the beer can be used by the yeast and lessen oxidation causing beer faults. Remember never to rack the beer during vigorous ferment since it separates the wort from the layer of yeast it needs.

At the micro-breweries the conical fermenters allow for the removal of sediment that may have flowed in from the kettle. A “hop dump” is performed after a day to remove this trub from the bottom of the fermenter. As fermentation subsides a “yeast dump” rids the fermentor of used up yeast cells to allow for a clean fermentation. We can duplicate these techniques at home to produce a cleaner tasting beer.

Whirlpool after you finish boiling by stirring the wort and let it rest for 15 minutes or more. Cool quickly to get a good cold break that settles out most of the trub so we transfer as little as posible. I don’t worry about some trub that gets by since the proteins can get incorporated into yeast cell walls. Keeping the fermentation temperature steady is critical and knowing when to separate the wort from the sediment helps to maintain quality. Every batch varies slightly so your judgement has to rely on watching the activity or lack of.

Secondary Fermentation

I usually figure the best time to rack is when the activity is reduced to a point where the foam is just a light coating on the beer. The beer stopped churning and looks a little less cloudy. Transferring to a secondary fermenter at this time has the same results as dumping sediment from a conical.

Flush the Star-San rinsed carboy or corney with CO2 so the transferred beer has a lesser chance of being oxidized. As you rack into the secondary check and record the SG, then taste it. Is it close to the final gravity you were looking for? Does it have the right amount of hop aroma and flavor you were hoping for? Did the yeast attenuate or is the gravity higher than you wanted?

A high gravity at this time may mean the yeast stopped prematurely. This could be from the yeast strain or underpitching or inadequate aeration. High mash temps could have produced lots of unfermentable dextrins. In that case your beer will be full bodied. If you’re not happy try adding some more yeast. Try some yeast nutrient. Some roust the sediment by stirring with a sanitized racking cane. Then watch for some more activity. Let it go and keep an eye on the airlock. Taking notes throughout the process will help in future brews so adjustments can be made.

If the hop flavor and aroma didn’t meet your expectations you could dry hop at this point by simply adding some to the secondary. I usually add one ounce of pellets that are similar in profile to the ones that were used in the kettle.

While the beer rests in the secondary watch the airlock making sure it always has a proper fluid level, preferably vodka, and observe the pops. Check the temps daily and keep it within the correct limits. At the brewery a sample is taken often and the gravity is recorded. They have a set final gravity that they know worked well with previous batches. When it comes to within 1 plato of the final they bung or close off the blow-off tube thus preventing the escape of carbon dioxide resulting in the carbonation of the beer. Their tanks can be presurized whereas carboys would explode. Homebrews are therefore fermented fully in the secondary to prevent posible problems down the road.

Do some math to figure out what the final gravity should be by looking up the yeast profile. An American ale yeast might have a 73-77% attenuation so an O.G. of 1.050 should have a F.G. say between 1.011and 1.014.

Depending on the yeast some beers may need a diacetyl rest. These are byproducts of fermentation that can give beer a buttery taste and texture. The good news is that 2-3 days longer in the secondary after fermentation is finished will give the yeast time to re-absorb diacetyl if it is present.


By observing the beer and checking the gravity you can judge when all seems done. The final gravity is reached and now you’re ready for the next step. You will then proceed to “crash” or cold condition prior to kegging.

With your alcohol spray bottle mist the area above the carboy a few feet up and it will settle to leave a sanitized air mass. Remove the airlock and cover the carboy with a solid stopper or plastic wrap tightly secured with an elastic band. Cover that with a paper towel and spray it with vodka then a piece of aluminum foil and set the carboy in a refrigerator at 37 F. The low temps and gravity will clear the beer of all suspended particles which settle to the bottom through time. When it’s ready you then rack the beer into the keg leaving all the sediment behind as opposed to kegging from the secondary then cold conditioning.

In the industry this is achieved by transfering beer from the fermenters to the brightening tanks via the filter where it is stored at low temps and the carbonation is checked and adjusted.

As the brew ages the flavors will blend to create the balance you are looking for.

Cold conditioning is sometimes avoided as some homebrewers filter their beer, but I feel it loses something in the process.

Some ales can be cold conditioned for only two weeks, since a slight haze is acceptable. When brewing an Alt I prefer to chill it for at least a month to give it that bright, sparkling appearance. The same goes for any lagers which I’ll chill for a month then keg and chill for a few more weeks to age further.

Homebrewers can learn to adapt the techniques used in the breweries to create some of the finest beers around. As you brew more you will come up with some of your own shortcuts. Enjoy!

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