Steam Beer

[kww]

All references I can find for producing steam beer (oops, "California Common", or Anchor's lawyers will be after me) show that traditional brewers use shallow, horizontal fermenters for the first few days of fermentation, and then transfer it to a more traditional tank for conditioning. Has anyone been successful using vertical tanks for the whole process? Any good theories as to what difference the early fermentation in the flat tank does to the final product, and how to compensate for it?

[Moonlight]

Shallow fermenters got rid of fermentation heat by passive air cooling. Larger tanks can today be cooled by glycol.

[Rob Creighton]

They are called coolships. I have seen a few copper lined versions lying around in old brewerys relegated to the dungeons, generally full of debris.

[crassbrauer]

I've never heard of coolships being used for fermentation, but rather for cooling wort to about 60 C after boiling is completed. The wort would be cooled further using another method afterwards, usually in something called a "Berieselungskühler" in German. In Belgium, however, Lambic is allowed to cool to room temperature in a coolship because it's one of the means by which Lambic brewers inoculate their wort, which would want to be avoided when brewing anything but spontaneously fermented beers. No fermentation takes place there, unless it's done by some fast-acting bacteria.


Coolships were made shallow for two reasons:

1. To let the wort "stink out" - a term one hears from older brewers. Due to the shallowness and large surface area of the wort, DMS and other volatile substances can still be driven out of the wort, although it is no longer boiling. By the time the wort cools to around 60 C, there's little DMS-P cleaving going on, so it can be cooled futher elsewhere.

2. Sedimentation of hot trub and perhaps a little cold trub occurs, as well.


According to legend, steam beer was fermented in tanks with heavy lids which popped up occasionally to allow CO2 to escape. Hence the nickname "steam". The yeast employed was apparently a lager yeast, but the temperature was too high for it, so their are a number of yeast by-products in the beer not found in a traditional lager.

[knock]

I know that at anchor's original brewery (and probably at a lot of the other "steam" breweries of the day) they pumped the wort to coolships on the roof, which also has been given as another possible origin of the term "steam"; would have been quite a sight.

[crassbrauer]

Coolships were the method for wort cooling and sedimentation of the day, so it wasn't limited to steam beer. There are still breweries in Europe who use them in conjunction with a plate and frame heat exchanger instead of a "Berieselungskuehler". Without a whirlpool, it's the only effective means for getting rid of the hot trub, if you can't afford more expensive equipment. I've attached a picture of a brewer cleaning out his coolship (I had to reduce it in order to be able to attach it to this message).

[kww]

My understanding is that Anchor still uses a shallow fermenter (2 feet deep). The beer is fermented in a shallow fermenter for three days, and then transferred to vertical tanks for 3 weeks prior to bottling. Are they getting something special by being old-fashioned, or is just the traditionalist showing through?

[BeersmithMT]

We have been brewing a California Common as part of our beer lineup for about 8 years. We have used both unitanks, and open shallow fermenters, although because of space considerations, we now use exclusively unitanks. Generally speaking, I think the open, shallow fermentation yielded beers that were more consistent in fermentation, and flavor. We did not apply any laboratory analysis to confirm this.

There is an informative section on fermenter geometry/tank hydraulics in "An Analysis of Brewing Techniques" by Fix & Fix that supports shallow, open fermentation tanks as being more consistent. The authors indicate that their blind taste tests favored beers produced in shallow, open fermenters. The authors also cite some studies by De Clerk and Unterstein that support use of shallow (height less than width/diameter) fermentation vessels. Their logic on why tank geometry affects fermentation seems to make sense - I have just never had the time scientifically verify.

[Moonlight]

The fermenters used at Anchor in SF do look like coolships, but they are the fermenters. The whole concept is that back in the 1840's, California was too hot to make lager beers, yet that was what the German immigrants preferred. The closest option was to use shallow fermenters (that look like coolships) so that fermentation heat would escape as easily as possible compared to a more space efficient designs (that could be used in cooler climates) which would get way too hot during fermentation and taste nasty. Today we have glycol and the ability to use any yeast at any temperature in any climate. (Can you see how easy we have it?)

Basically my take on Steam Beer is that it is a lager that is fermented warmer than the European traditions by necessity.

Again because of the lack of refrigeration, it was common practice at that time to use a coolship for the cooling wort on the roof, but that was a separate vessel, and separate part of the process.

[crassbrauer]

Tank Geometry

Cylindroconical tanks allow for better substrate contact with the yeast due to the convection within the tank. Shorter, wider tanks do not allow as much contact due to lack of convection. As a result, cylindroconical tanks produce beers with fewer yeast by-products, all things being equal.

[kww]

I think I understand now. I'm looking at Common for much the same reason that it was invented in the first place ... a population that has been raised on a German pilsner (Polar) and high electricity costs that make me want to keep everything as warm as possible for as much of the brewing cycle as possible. If someone could perfect a 28C brewing cycle, I could just use a ground cooling loop for the glycol. Doesn't sound like there's any good reason to believe that the special fermenters are required, and I can run my numbers based on using the same equipment for lagers, common, and ale.

[Capt. Bob]

California common....Lager yeast at Ale temps. Northern Brewer hops.
That's pretty much it in a nutshell.
You want shallow fermentation?
Split a 7bbl batch between two 7bbl fermenters.
Brewing should not be this complicated!


Bob Sylvester
Saint Somewhere Brewing
Tarpon Springs FL

[randowilson]

Steam Beer.

For years, I produced a steam beer. It won several gold medals at the GABF and silver at the WBC. Fritz and company did sue, and we eventually were ordered to cease and desist.

All fermentation was done in cylindroconical vessels at a temperature of 65 F. The steam beer was lagered for 45 days..also in cylindro's. I do not know of any advantage to using shallow, open fermenters. The yeast I used was a hybrid, and offered both a rapid attenuation and high level of flocculation. That would be the only real advantage...surface area.

[creature ash]

My understanding with shallow fermentation was that it produced higher levels of fermentation by-products. apparently some small belgian breweries that have upgraded their breweries have been known to half fill cylindro-conicals to re-produce this effect.

Although Im not sure if this would have had any impact on vessel design for 'steam beers'.

[pubbrewer]

Shallow Fermenters

I beleive historically the long shallow fermenter was to allow heat to rapidly disperse when fermenting on the west coast without the modern refridgeration that the "high tech" lager breweries had back in europe, circa 1800's. This allowed the lager yeast to be used without high build up of heat in deeper tanks. The shallow depth aided in quicker fermentations due to good oxygen pickup and lots of surface area increasing production and profits.

Anchor Steam Brewery still uses this style of fermenter for their flagship product in a positive air filtered room. I am uncertain if the room is chilled or the tank has any jacketing on the bottom I have heard neither but again I doubt that. The depth of the fermenting beer is under 2 feet I believe.

The term "Steam" was supposedly from the tapping of a keg blowing of steam due to refermenting AKA cask conditioning. This is all from people I have talked to who work in the SF brewery.

Belgian and some breweries in Dusseldorf for example use cool ships to chill from boiling to around 90-110 then send through a Bordeau chiller or modern plate heat exchanger. Europeans have allways been more consevative when using wastefull amounts of energy.

The point of filling large tanks less than full is to lessen the impact of convection which affects the ester profiles. The ideal tank for some classic beer styles which even include Czech pilsner is one to one ratio, height by width.

Cheers Dean
San Diego Brewing Company
America's Beer Paradise!