Nitrogen vs Diacetyl in young lagers?

[jason.koehler]

I almost hate to be asking this...

Our lagering capacity is maxed right now, with ordering coming in faster than we can make our lager. If I had my way, I'd like to keep our lager on the yeast for at least 10 days before filtering/aging, but we don't have that luxury if we want to keep up with sales...

We have a nitro beer in our lineup, so we have some mixed gas lying around. I remember reading somewhere that some large breweries spray their beer with nitrogen after primary fermentation to get rid of diacetyl for faster packaging...anyone familiar with this process?

I was thinking of testing this on maybe a 1/4th of a batch by pushing it through the bottom of the tank and letting it bubble up and out of the beer, then carbonating as usual. Any thoughts on this?

[Sauce]

Hey Jason,

Never heard of the Nitrogen "spray down" for D reduction, but I did remember seeing this a few months back. Its a enzyme designed to reduce alpha-acetolactate into acetoin thus eliminating the rest at higher temps for the yeast to do the job.

http://www.novozymes.com/en/MainStructure/ProductsAndSolutions/Brewing/Optimal+fermentation+and+maturation/Maturex/

JackK

[Larry Horwitz]

the nitrogen won't make any impact on D reduction. AAL must be oxidized to D and then reduced to Acetoin by yeast (or the enzyme listed above)...but you might want to consider that D reduction is only one small part of the maturation process. Have you considered a different yeast? How long is your total tank time for lager beer?

[gitchegumee]

A Miller brewer I worked with used the technique you described. He would use CO2, not N2 and it would accelerate the conditioning process not by diacetyl reduction, but by acetaldehyde reduction. Your best bet for diacetyl reduction is either time, or more importantly by temperature. The curve for reduction is highly influenced by temperature. Best of luck, I have been there and know that if you want to keep sales high, you had better keep the product delicious. Cheers!

[jason.koehler]

Thanks for the suggestions guys.

I found the reference, it was just a sentence in Principles of Brewing Science where Fix says something about how "The world's largest brewer" sprays their beer with nitrogen to neutralize diacetyl...pretty vague considering he didn't mention the brewer by name, and who was the largest brewer when it was written?

Given normal fermentation time, we don't have any problems with diacetyl with our yeast, but due to production demands, we're taking it off the yeast, filtering, racking, and pasteurizing in about 7-8 days...too fast we know, but the second we don't fill our orders is the second our picky customers start looking for another provider. Restaurants in Japan typically only carry one beer on draft, and if we don't meet their demands, we're out.

So, I'm tasked for looking for ways to keep the diacetyl levels down for the time being until we pass the busy season...which lasts another 6 weeks...

Beer purity laws are pretty strict here, I doubt the enzymes would fly with the tax nazis...any other suggestions would be appreciated.

[dick murton]

It's a shame you don't mention what your current fermentation temperature is. If it is less than say 15, allowing the temperature to rise a few degrees, and I suggest her that it is no more than 15 will speed up diacetyl. It will be a bit of trial and error, because the warmer it is in the first place, the less residual sugar is likely to be required per degree C temperature rise. If you let it just get to the final higher temperature as the sugars run out, this will speed diacetyl degradation without affecting attenuation or yeast vitality too much.

Cheers