From the HBD Archive
From: David (D.R.) Brown <DRBROWN@BNR.CA>
Subject: Fermentation lag time.
Date: 1992-04-30 18:10:00 GMT

I brewed an all-grain IPA last weekend using "British Ale" Wyeast (1098),
After bursting the inner pouch, the Wyeast packet expanded before I was
ready to use it. I tried to buy some time by pitching the contents into a
1/2 gal, 1.020 SG starter of corn sugar and water.

Two days later I was ready to pitch the starter, but its SG had only reduced
by a couple of points. I pitched anyway but after three days there was
no sign of fermentation. A lag time of three days seemed a bit excessive,
so I decided to dump in a package of dried yeast. Now the fermentation is
in full swing.

I now realize that the starter should have been made with malt extract, NOT
sugar. Still, why did the yeast lose its spunk after it hit the sugar water?
Did I induce the dreaded Crabtree effect in my starter culture? If so, why
didn't the yeast recover after three days in the wort?

Even though I used a wort chiller, a considerable amount (~1/2") of material
precipitated out after the yeast was pitched. Is it also possible that falling
trub took some yeast out of suspension, burying it in the bottom of the
carboy? It seems to me that this would contribute to the lag time.

Any thoughts or suggestions?


- Dave

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