Question about oak tanks

It depends what "oak character" you're looking for. If you are talking about sour beers, such as geueze and other lambics, some breweries and blending houses have been using the same barrels for decades. Some of the barrels were reparations from Germany to Belgium for WWI. These barrels are used because their wood contains organisms such as lactobacillus and pediococcus that add their own (usually sour) character to the beer, along with some oaky notes and tannins.

 

“To clarify what I meant by "oak character," basically I mean vaguely whatever qualities are intended to be derived by aging the beer in wooden tanks.”

There is no simple answer to that since each beer style will be seeking different “qualities” from being aged in oak. For example , aging in bourbon oak barrels is to obtain both the flavors of oak but also the residual flavors of the bourbon that was previously in those barrels. In that specific case you would not want to reuse those particular oak barrels too many times; maybe just once.

For other oak (or other wood) aged beers the ‘answer’ may be different depending on what the goals are.

Cheers!

 

The oak tanks in the first picture are probably lined with pitch to keep the beer from the wood. You can find the Beerhunter episode on line that shows similar tanks at PU being maintained, pitch was replaced every time the lagering was finished.

Edit - I see those are wine casks pictured, so those are unlined.

The Rodenbach tanks are disassembled and about 1/32 inch is shaved off to remove beerstone. Those Foeders are good for 100.years at that rate.

 

I suspect it's gone after 5 batches give or take. I'm extrapolating from the little I know about spirit barrels. I figure the ratio of solution (beer) to wood surface ratio only increases from individual barrels to puncheons, foeders, etc. so I can't think of a reason why those larger vessels wouldn't be more susceptible to the alcohol extraction process. I think oilier or less porous woods like palo santo are probably a whole different ballgame.

I think any brewery running a program with barrels that size is constantly repairing, reconditioning, and eventually retiring and replacing. So there's a source of new wood even if you're not expanding the number of vessels. Then I guess it's up to blending to achieve how much character from the new wood you want to present.

 

I like this part. :-)

 

In addition-
Firestone Walker only has a Barrel in their union system for 30 days, then it is retired.

Some use oak staves/strips, or even honeycombed oak to infuse flavor.

 

Sometimes its not new wood you are after.
in Large foeders i would expect them to never be fully empty of beer (that has been hanging out for a year or two or more) just has a new beer racked on top. an empty barrel is an unhappy barrel as it dries it becomes less water tight.

Vinnie Cilurzo (Russian River Brewing)- "We actually never hold barrels empty. If they are empty, we either fill them immediately or they go into the throw away pile.". "I take this stance because even after cleaning a barrel with our pressure washer there is still some beer, bacteria, & alcohol left in the wood and as it is exposed to air the chance of the growth of acetic acid is greater. Of course one can use sulfur sticks to eliminate the oxygen but again, when one has access to barrels like we do, it is just easier to grab some fresh barrels."

I believe that RR keeps a barrel for 5 beers or so, depending on condition, then its retired.

Jean Van Roy- (Brasserie Cantillon)- "We clean our barrels first with steam and then a rotative head linked to high pressure water. Then with warm water and chains added into the barrel. For this last operation, we put the barrel on a rotative machine and we let it turn for 20 minutes.". "The barrels filled in the next 2-3 days are used fresh. For the ones we have to keep for more than 3 days, we burn a sulfur stick inside to avoid moisture."

I assume even the biggest barrels would use some of the same methods or a combination of. And i know these are mostly lambic/lambic-like beers who want to maintain the character of a few runs in each barrel before dismantling. And the fact that both example breweries are relatively close or almost ontop of large wine producing regions helps acquire the barrels they need.

But the DFH foeders im sure get the same Clean in Place program ( or close to) as the rest of their stainless steal takes and maybe a bi monthly scrub with citric acid and cold water and maybe a extra close shave with a planer.

 

I know that lots of wineries use oak inner staving in large stainless steel tanks. The oak can be replaced in the steel staves when needed. It is a more economical way to achieve varying degrees of oak character.

 

Interesting information about using and cleaning barrels, but @draheim is asking about wooden tanks, specifically. Granted his question was a little open-ended, but I too am now curious what wooden tanks do for beer vs stainless tanks vs barrels and the difference in care required by brewers. Or why would a brewer choose to use a wooden tank over stainless or over barrels?

Thanks @hopfenunmaltz for your information. I would have never considered coating tanks in pitch, but that makes perfect sense for any pre-industrial revolution brewer or modern brewer staying true to tradition. I wonder then how much the pitch would have changed the flavor of the beer?

I am going out on a limb here, but I wonder if @jesskidden or @patto1ro could add some facts, history, or references to this discussion.

 

Lots of discussion of using pitch and other coatings for wooden brewing vessels, in both the US and Europe, when the topic drifted in this thread, starting around my post at http://www.beeradvocate.com/communi...he-craft-community.242192/page-8#post-3122097

In the US, pitch was mostly used for copperage (even for steel and aluminum kegs once they became available in the post-Repeal era, before Stainless was universally adopted). In US breweries, it was eventually more common, safer and easier for large wooden fermenting and aging tanks to use other types of neutral coatings - Mammut was a popular substitute product, and the one used at Ballantine for their "Aged in the Wood" IPA and a few other beers. Enamel, varnish and lacquer, specially formulated for the brewing industry, were also used. See some ads and other info at my page https://sites.google.com/site/jesskiddenparttwo/home/pitch

No US brewery would have ever used "bare" wooden vessels. As the MBAA put it in their 1946 edition of The Practical Brewer:

 

Most of the wood tanks are intended to be around for awhile. August Schell installed cedar tanks (flavor neutral) around 1935 and used them until the mid-1990s when they replaced them with stainless steel. They were coated on the inside to prevent infections. Jace Marti (current brewmaster) found the old tanks and he is now brewing Berliner Weiss in them. He cleaned the coatings off the inside and the surface is now bare wood. The wood provides a medium for the wild yeasts (Brettanomyces) and bacteria (Lactobacillus) to grow. This would also apply to Lambics, Gose, and other sour beers.

In a lot of cases when fermenting non-sour beer in wood tanks, the tanks are probably coated on the inside so that they do not provide places for wild yeasts to grow and would tend to be flavor neutral.

Aging in oak and wood barrels is another thing. They are not coated and do impart various flavors to the beer. I know some brewers do reuse these but each time you increase the chance for the growth of wild things you may not want in the beer.

 

I asked a similar question while on the DFH tour. From what I remember (I had a few 120 mins that day) they said that every few years they have the interior sanded to expose fresh wood to the beers. Not sure of all the technicalities, just going off of memory.

 

Might be apples to oranges, but I have a buddy who just bought a small oak cask to age his homebrews. He was told it would hold up for 4-5 batches of oak aging and after that should be used for sours only.

Ties in with what @pat61 said above

 

I can give you a little insight from our experience at Schell's. As was mentioned earlier, we have 10 of our original cypress (not cedar) wood lagering tanks. They were built in the brewery in 1936 and used continuously until 1991. cypress wood was popular with lager breweries because it didn't impart the strong tannins that oak does into the beer. It's relatively flavor neutral in comparison, but it's still wood. We lined our tanks with pitch. This was a process that was done once a year. The cellar man would climb inside the tank with a bucket of hot pitch that sat on top of a burner, a paint brush, a torch, and a big scraper. He would flame the side to melt the pitch, scrape it off, and then brush on the new stuff. As you can imagine, it wasn't an exact science, and there was no doubt wood showing in places, hence the cypress. I would imagine that breweries that were using oak tanks, would have ended up with some flavor pick up early on, but after several cleaning cycles, most of that flavor would have been stripped out. The size of the tank would also play a role, with less surface area, and less chance for flavor pick up from the wood. I was too young to have any of our regular beer that was aged in our cypress tanks, but after we restored the first tank in 2011, we put a sacrificial beer in it to age for 3 months just to see what would happen. Nothing. No real flavor pick up at all from the wood- and this was after the tanks had been dry ice blasted and exposed the "fresh" wood. After a fresh clean, it had a definite wood aroma that I can't put my finger on, but there isn't any real flavor imparted in the beers we make now, even after they've aged for over a year. The tanks that we just pulled out of storage, with the pitch inside, had a nice pleasant pine sap smell to them that comes from the pitch lining. we still have bricks of the pitch left, and when you melt it, it has a very strong pine smell that I can't understand how that would not have somehow ended up in the beer aroma. Anyway, that's a little insight from our experiences with 80 year old wooden tanks.

 

Pitch over the wood reduces or prevents the chances of infection and once upon a time all beers had to be done in wooden tanks, so for some beers, use pitch. Also if you don't want wood flavors in the beer the pitch reduces or eliminates those.