Dr. Brian Nummer PhD


Author: bnummer

Fermentation culture safety

Okay.  I have been asked many times what verifications are there that a particular fermentation culture is safe, “clean” or “pure”?  Whether its yogurt, kefir, sourdough, kombucha, buttermilk, cheese, or koji; the question remains. For the most part, natural fermentations are quite rigorous and the true culture organisms predominate.  If foodborne illness organisms get into […]

Dry aging meat in “special” bags

Dry aging beef (and other meats) is said to enhance flavor and tenderness.  It is often used by upscale purveyors to distinguish their products from others.  Dry aging meat is essentially aging meat without protection is a refrigerator.  Cuts are stored separate from each other to permit air flow to dry them in 1-6 weeks.  […]


Kefir Brian A. Nummer, Ph.D. November 2004 (originally written for the NCHFP/University of Georgia) Updated with Retail-foodservice options April 2015 SOP=standard operating procedure; CCP=critical control point Kefir is a cultured-milk beverage believed to have originated many centuries ago in the Northern Caucasus Mountains. Kefir has a uniform creamy consistency, a slightly sour taste somewhere between […]

UV pasteurization of juice

UV light can be used to achieve an effective pasteurization of juice to meet the 5 log pathogen reduction requirement of the FDA.  The UV light is absorbed by pathogen DNA to the extent it leads to cell death.  At least one manufacturer has demonstrated effectiveness for killing both Escherichia coli 0157:H7 and Cryptosporidium parvum oocysts. […]

ROP Refrigeration temperature datalogger solution 1

There are several solutions that work for refrigeration temperature monitoring. Here are two options that come from Thermoworks, a company in Utah. The first product is a temperature datalogger that requires a docking station to upload measurements.  This product has been tested by the author and it works as described by the manufacturer.  First – […]

ROP Label Printing

Many operators struggle to find the right solution for labeling ROP bags under the Food Code and their HACCP program.  Here a few reviews of products that have worked in our ROP lab to get you started.  (No endorsements implied, just tested). First there are two types of printing technologies for labels: direct thermal and […]