skim milk agar

Jan Hoolwerf hoolwerf at
Mon Mar 17 01:56:44 EST 1997


Kimberly Walker <walker at> wrote:

 KW> How in the world do you make this stuff?  I tried to filter
 KW> sterilize the skim milk, but it wouldn't go through the filter.
 KW> Autoclaved milk carmelizes.  Does anyone have expeience with
 KW> this?

We routinely use Plate Count Agar (PCA, Difco i think) with 5% skim milk made
from spray dried milk powder.

Just dissolve the milk powder (or the equivalent amount of milk made from
this powder) in the agar before sterilising and steam sterilize 15 min. 120 °C
as usual.

In this concentration you will not notice carmelization and what we use is an
official method in the Dutch dairy industry.

with regards, Jan Hoolwerf

******************* these words were mine, all mine !! ********************
 J.D. Hoolwerf
 Neth. Inst. for Dairy Research
 P.O. Box 20                        phone  : 31-318-659511
 6710 BA  Ede                       fax    : 31-318-650400
 the Netherlands                    e-mail : hoolwerf at

More information about the Methods mailing list