Fermentation - Let Them Eat... The Yeast That Is!

Fermentation is where yeast (and sometimes bacteria) transform the finished wort into beer and carbon dioxide.  We need to keep oxygen and potential contaminants from getting into the fermenter, but we also need to release excess CO2 so your ferementer does not explode from the pressure build up.   During the mash, there is not a lot of opportunity for spoilage or contamination from unwanted microbes, and the boil will actively kill the microbes.  But once we cool the boiled wort down, sanitation becomes extremely important!  We want the yeast we have carefully selected to feast upon the wort we have crafted for them, not bacteria or wild yeast or leftover yeast from a different beer.   We can use the plastic buckets from the homebrew kit, we can use a plastic or glass carboy, or for a little more money we can use a stainless steel fermenter.  There are even relatively low-cost plastic conical fermenters available that can handle advanced techniques like pressure fermentation.  Stainless Steel has natural properties that reduce the risk of spoilage, and that is why we see so much of food and beverage equipment made from stainless steel–and they come in a lot of options that include budget-friendly variations that are within reach for the average homebrewer.  We’ll talk more about stainless steel in a bit.  

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Star San is the sanitizer of choice for every homebrewer I know.  It is an acid based sanitizer that is quick, odorless, tasteless and safe for most materials except softer metals. It foams up when you spray it on your equipment, you let it sit for  a minute or two, then drain off the excess.  No drying, no wiping, no anything crazy.  Just spray, drain, and you’re ready to use the equipment.  I keep a spray bottle to spray on bigger equipment, and a small bucket full for smaller stuff.  It comes concentrated, just mix 1 oz of Star San per 5 gallons of water, so a single bottle will last you awhile.

Primary Fermentation

As the yeast fulfill their glorious destiny, they will sink and collect at the bottom of the fermentation vessel.  For this reason, we describe the fermentation process as a primary stage and secondary stage.  Over the course of approximately 3 days to 1 week, the yeast will take the oxygen we’ve provided them in the fresh wort, and reproduce or multiply.  After the oxygen levels start to diminish, they will begin to produce alcohol and carbon dioxide (CO2), converting the wort into beer.  This is the primary fermentation stage, and the fermentation vessel is the Primary Fermenter.  At the end of this period, much of the yeast will “die” and sink to the bottom, creating a bed of sludge. 

Secondary Fermentation

Common homebrew practice is to remove the “dead” yeast either by draining it out the bottom of a conical style fermentor or racking (transferring) it to a secondary fermenter (hence the name secondary fermentation) in a bucket style vessel.  Some people skip this step and are happy with the results, but I think the majority do remove the excess yeast.  Once removed, the yeast can be collected and saved for future use, or discarded to the compost pile.  For hop-forward beers, this is usually the point where we add more hops (dry hopping) to the fermenter or in coffee beers we might add coffee beans or grinds, maybe vanilla beans, or possibly [gasp!] fruit!  Again, while we’re removing the dead yeast and adding hops or coffee beans or fruit, we want to be especially mindful of sanitation and not contaminate the beer. While there are still plenty of healthy living yeast cells swimming about the fermenter, and the batch is not as vulnerable as it was before we introduced the yeast, there is still an opportunity for infection that could make the beer un-drinkable.

What do I Need? Fermentation Equipment

EZ on the Wallet - Plastic Carboys and Conicals

For beginners, the bucket that comes in your kit will be fine for brewing good beer.  Eventually you will want to upgrade though and the next step up from the bucket is the carboy.  Traditionally, glass carboys (water cooler bottles) were highly coveted for this task. Improvements in food grade plastic have reversed this and the overwhelming benefits in weight and safety of food grade plastic over glass (glass carboys explode when dropped), have made the plastic version the preferred vessel.  You’ll want a little headspace in your carboy, so for a 5 gallon batch we recommend a 6 gallon carboy.  Glass Carboys run about $53, which we do not recommend, and Plastic Carboy with built in spigot is only about $38.  For $40 you can get a wide-mouth Fermonster brand plastic fermenter with a spigot and a wider opening at the top–if you’re going Carboy, this is the one to go with.  Even if you have pricer fermentation options (conical/stainless) it’s always nice to have a couple of fermentation buckets and plastic carboys around for transfers and other things that come up.

For a little more money you can get a plastic conical.  The design of a conical shaped fermenter  allows you to dump the “dead” yeast, spent dry hops, coffee grinds, fruit, etc,  without racking to a secondary fermenter.  No racking transfer means:

  1. No Secondary Fermenter (lest equipment cost or clutter)
  2. No transfer of wort between primary and secondary (reduces contamination risk)
  3. And one less step for you to perform (time savings)

Some models even allow for pressurized brewing (make sure you do your research before attempting fermentation under pressure) which can greatly improve the speed of the fermentation, as well as, minimize any off-flavors if the yeast runs hot (we’ll do a post on pressure fermentation soon).  

For about $90, you can get a 7,9 gallon FastFerment.  The FastFerment has a cup at the base of the plastic conical fermenter that holds the spent yeast that is easily detached to empty while keeping the wort save inside the conical.  Slowpaddle South has one of these and he loves it!  

If you want to have the option of pressurized fermentation, the 7.1 gallon FermZilla Concial Pressure Brewing Kit sells for $241, but currently on sale at MoreBeer! for $211.  This gives you the advantages of a conical fermenter and a unitank (basically a fermenter that holds pressure) at the cost effective price of plastic!  Also availabe is the FermZilla All Rounder Pressure Brewing Kit – 7.9 Gal on sale for $124.

Stainless Steel Conical Fermenters

If you want long lasting sturdiness, sleek authentic look, and bacteria thwarting benefits of stainless steel, you have a LOT of options!  But like everything, they will cost a bit more.  We can break the options down like this:

  1. Bucket Style
  2. Conical Fermenter
  3. Unitank

Ss BrewTech BrewMaster Brew Bucket – 7 gal. Fermenter

Our experience with SS BrewTech has been all positive, and they usually include most or everything you need where some other brands tend to be more al-la-carte.  The BrewMaster Bucket is a stainless steel fermenter bucket with a built-in racking valve, built-in thermometer, and a bottom that is conical in shape–not the extent that a true conical fermenter is, but it’s better than flat.  At $280, this isn’t a bad option to get the benefits of stainless steel 

Ss BrewTech Chronical Fermenter Brewmaster Edition – 7 gal

Ok, now we’re getting Big Time! This is a true stainless steel conical fermenter, a scaled down version of what you find at professional breweries.  The real deal.   So for $600, what am I getting?  Well let me tell you, you’re getting pro-performance and options.  You get a 7 gallon conical fermenter made of 304 food grade stainless steel.  It comes equipped with a 3” TC lid port, clamp, gasket, and cap.  TC (tri-clamp) connectors are what the pro’s use, they kinda look like single hand-cuffs.  they wrap around whatever you’re connecting, then you screw the locking mechanism tight.  They are standardized, so you have a bazillion options of what you can connect to them.  Also included are butterfly valves–you just squeeze and twist– a thermowell and LCD thermometer, and etched volume markers on the inside so you know how full your fermenter really is.  The legs have threaded inserts if you want to add casters.  They’re pretty awesome!  For $769 you can get the 7 gallon conical and add on the FTSs Heating & Chilling Package. 

If you want to experiment with pressurized fermentation, the SS BrewTech Unitank comes with the extra gear you’ll need for $1,090

BrewBuilt™ X1 Uni Conical Fermenter

The BrewBuilt version is pressure-fermentation capable if you add on the optional Fermentation Under Pressure Kit for an extra $300.  These are decent quality fermenters at a more budget-friendly price point, but they tend to be more of the al-la-carte style of ordering.