Dr. Cone asked: "I am curious why are you interested in a procedure for rapidly increasing the cell density of Brett? Lambic beer?"

That is exactly why. I can't get enough lambic beer. Which leads to another question or two, if there is space/time to answer. An 11 month old lambic with the waxy pellicle at the top behaves very differently at only slightly (in my mind) different temperatures. Between 70 - 74F there appears to be little, if any activity in the carboy. But if the temp in my closet (where it's stored) gets above 75, a steady stream of extremely tiny bubbles (assumed to be CO2) are seen. I originally thought that it was simply CO2 coming out of solution, but the thickness of the waxy layer at the top seems to shrink and grow (slightly) with the temp too.

It seems odd that there would be such an on/off temperature range for the yeast and bacteria to be active at - any ideas? I never allow the temp in my house above 80F, so I don't know if the activity continues to accelerate past that point.

Also, I know the phenomenon we call beer skunking is a result of light and hop oils reacting, but I am wondering if my nightly ritual of shining a flashlight into the carboy may be having any negative effect on my yeast? Photosensitive yeast?

-Eric Dahlberg

RESPONSE:

I really have only a smattering of experience with Lambic beer. Dr. Jean-Xavier Guinard's book Classic Beer #3 Style Series LAMBIC ISBN: 0-937381-22-5, should give you all the information that you need.

The literature mentions light struck and sun struck in the same sentence as if they were the same. The sun rays have the light spectrum that has the energy to cause the problem with the hops. I have seen many good beers made in clear glass carboys located in a kitchen, cellar and closet with electric lights with no apparent problem with light struck/sun struck. So a flash light should not be of any consequence. I am willing to be corrected if I am wrong.

Dr. Clayton Cone