Sunday, November 6, 2016

My Brewing Process, Part 4 - Fermentation

Up to this point, I've selected a recipe, milled the grains, mashed them, completed the boil and transferred the wort to a fermenter.

Fermenter Choice

For primary fermentation, and often for secondary, I use an SS Brewing Technologies Brewmaster Bucket.

I started out with plastic bucket fermenters, which I liked because of their inability to be broken, relative lightness, and ease of cleaning relative to a glass carboy.

Then, I migrated to a plastic Better Bottle 6.5 gallon fermenter. This worked fine but had the downside of being difficult to transfer the wort to a bottling bucket. Recently, I retrofitted the Better Bottle with a spigot so that I could get wort out of it without the need for a siphon. A friend of mine had a bad experience with contamination from a siphon, and I've vowed to eliminate them from my own setup if at all possible.

Finally, I invested in the SS Brewing Technologies Brewmaster Bucket. I also invested in a Chapman SteelTank stainless fermenter.

The Chapman is a good fermenter but lacks a thermowell and can't easily be used with a blow-off tube unless you do some modification.

The SS Brewing Technologies fermenters work well with airlocks and blow-off tubes, can be stacked one on top of another, have a conical bottom, a thermowell, and a valve design that makes it easy to avoid sucking up much yeast when transferring to a bottling bucket.

I typically use the Chapman as a secondary fermenter. I also use the Better Bottle as a secondary fermenter when the stainless units are busy.

Temperature Control

I brew a lot of Belgian style ales. If you read Stan Heironymous' Brew Like a Monk, you'll find that most trappist monasteries don't rely on temperature control. They prefer to let the yeast run wild during fermentation, which helps it generate the flavors associated with trappist beers.  For that reason, I didn't invest in temperature control at first. Then I invested in the heating side, to keep my Belgian style beers high up in their temperature range. This ensured that I got the flavors I wanted and helped the yeast to finish out fermentation.

More recently, I've been branching out. My current setup includes a small Haier refrigerator that is large enough to hold a Brewmaster Bucket if needed (for lagering type temperatures) and large enough to hold a large water reservoir (for ales that need some temperature control but not complete refrigeration).

Cat litter bucket as water reservoir for cooling system
Temperature Control is provided by the Inkbird ITC-308 or ITC-310 dual-stage temperature controller. This is a pretty foolproof, inexpensive controller that has worked well for me with both heating, cooling, and combined applications. It took a little work to get the temperature probe to read correctly. Since then, it's mostly a set-it-and-forget-it operation. I tell it what the high and low temperatures are for the beer I'm making, plug the heating and cooling systems in, and put the controller's temperature probe in the thermowell. From there, the controller takes care of everything. If the beer gets too cold, it kicks on the heat wrap. If it get too hot, it kicks on the cooling system.

Heating is provided by a fermwrap fermentation heater. This costs about $24. It looks like a plastic sheet and wraps around the fermenter. I usually hold it in place with a couple of pieces of tape. When the Inkbird kicks it on, the wrap heats up and warms up the beer gradually.

Cooling is provided by the Haier refrigerator, a water reservoir made from an old (cleaned out) cat litter bucket, a submersible pump, rubber tubing, the Cool Zone Fermentation Cooling Jacket, and an Igloo Marine Cooler.  If lagering temperatures are needed, I'll move the fermenter inside the Haier refrigerator and let the Inkbird keep things at the right temperature.

Cooling system and fermentation chamber setup, but open for photo
I'd been considering building my own insulated fermentation chamber. As I started to price out the parts I was going to need, I suddenly realized that a fermentation chamber is nothing more than a beverage cooler stood on one end so that the lid becomes a door. Amazon had a used marine cooler large enough to hold the fermenter for around $54 with free Prime shipping. That meant no need to build something and a well-insulated fermentation chamber.  All it took was drilling a few holes for the cooling system hoses and wiring.

Thoughts on Primary and Secondary

There are different schools of thought on whether a secondary fermentation is actually necessary. The concept of a secondary fermentation goes back to the early home brewing days when ingredients were not as good or as fresh, yeasts not as well understood, etc. There are many who say we no longer need to do secondary fermentation in a separate vessel. Others swear by it. I'm somewhere in the middle.

For most beers I brew, I don't rack the beer off the yeast until right before bottling. This hasn't resulted in any off-flavors that I can detect, and has reduced the risk of contamination associated with transferring the beer to another vessel. I've left beers on the primary yeast for as long as two months with no ill effect. 

That being said, I do sometimes rack the beer into a secondary fermenter. I do this for high-gravity beers where a long secondary fermentation is needed, so that there is less risk of autolysis damaging the beer's flavor. I do it for any other beer that needs more than two months of secondary fermentation time for the same reason. I'll also do it sometimes if the beer seems too cloudy and I think maybe racking it off the yeast will clarify it. I will also do it for beers being entered into competition, where I want them to be as bright and clear as possible.  Still, this hasn't been something I've done more than a few times.

Getting Ready to Ferment

Once I've transferred the beer from The Grainfather's kettle into the fermenter, I insert the thermometer into the thermowell to check the beer's temperature. During winter months when our tap water is colder, the beer typically hits the fermenter ready to pitch. In the summer months, when the tap water is warmer, the beer may be as hot as 83F when I transfer it into the fermenter.

If the beer's not at pitching temperature yet, I'll wheel it over to my temperature control setup on my hand cart (to save wear and tear on my back). Once there, I'll put it in the cooler. I'll insert the Inkbird's temperature probe in place of the SS Brewing Technologies thermometer, then wrap the fermenter with the cooling jacket. I'll close the door on the cooler and let the cooling system chill the fermenter down to my yeast pitching temperature.

With the beer at yeast pitching temperature, I'll pitch the yeast. For liquid yeast or batches involving a starter, I'll pour them in. For liquid yeasts, I'll typically pitch them dry unless it's a higher-gravity wort, in which case I'll rehydrate them first.

I button up the fermenter, attach the heating and cooling wraps if not already done, insert the temperature probe for the Inkbird, set it with my desired fermentation temperature range, and let it be.
If a multi-step fermentation schedule is called for, I'll use my InkBird ITC-310 controller, which can be programmed with up to six temperature steps.  For single-step fermentations, I'll use the ITC-308, which is simpler to program.

Fermentation

I treat fermentation as a largely "hands off" process. I give the yeast at least a week before checking the gravity.  I'll open the valve at the bottom of the fermenter and dispense a small amount of wort into a clean plastic cup.  I'll use a pipette to put a few drops on my refractometer and get a reading.  I'll compare this to the final gravity I calculated in BeerSmith earlier.  If the gravity is close, I'll give the beer another couple of days and check the gravity the same way each day.  If it doesn't seem to change, it's time to bottle.

For beers where I feel a secondary fermentation is warranted, I'll take the fermenter out of the temperature control setup and put it on my cart.  I'll wheel it around to another part of the basement and put it up on my brewing table.  I'll sanitize the secondary fermenter and transfer tubing, then transfer the beer into the secondary fermenter.  I'll wheel this back to the temperature control system and hook it up.  The beer will stay there until it's ready for bottling.

In the next installment, we'll look at cleanup.  Bottling will be covered in the final installment.

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