I'm brewing two Coopers kits at the moment - a Pilsner and an India Pale Ale. Both have a generic leaflet which suggests I should leave 6 days at 21 degrees for fermentation (which seems quite short) or measure the SG as consistent over 2 days.

I'm now on day 12. The Pils SG is consistent but there are still bubbles rising. The IPA has dropped from 1.008/7 to 1.006 in the last two days and also has bubbles. I've only just started taking SG readings for brews - up to now I always went on the more amateur "are there still bubbles rising" method of detection.

My temperature has probably been a little low. I keep the fermenters in my hot press in the house, but it's been unseasonably cold the last week. When I check the temp it's usually about 19/20.

I don't want to bottle too early as I'm afraid of exploding bottles. Are my brews ready?

  • WHY WHY WHY do these beer kits give such horrible temperature advice?!? 21C/70F for a "Pilsner" kit?!?!
    – GHP
    Mar 18, 2013 at 12:14

2 Answers 2


You say its taking "Far Longer." how long have you been fermenting? What is the gravity of the pils? if your IPA gravity is 1008/1007 over the last two days I would say your pretty near finished. Assuming your IPA was in the 1050s/1060's when you started; you got great attenuation, I would check gravity again tomorrow and if your getting the same range go ahead and bottle.


I wouldn't give the instructions too much thought, most kits suggest the same fermentation period and in my experience they are always wrong.

Also you dont need to worry about temperatures down to 17c - in fact lager yeast likes it cold.

I always leave 2 weeks for primary fermentation, then transfer to a secondary fermenter for a further 2 weeks. At that point it goes into bottles and is left for another 4 weeks before the first bottle is opened.

This always works for me and the beer is always fine.

Although it is interesting to measure, dont worry about the SG. You risk contamination every time you take a sample, and the beer can take care of itself

  • 1
    I don't think the coopers kits provide actual lager yeast with their kits - they're all ale yeasts. If they did, 17c would be far too warm!
    – mdma
    Mar 16, 2013 at 12:51
  • thanks, I don't have a secondary fermenter so it has to go straight to bottles. that's next on my shopping list!
    – roryok
    Mar 16, 2013 at 13:37
  • 1
    Secondary fermentation is not always necessary and I think most homebrewers don't do it these days. I seldom do. Taking gravity samples is the only way to know what's going on...bubbles are unreliable as indicators. In your case, you could be seeing bubbles due to CO2 release due to temp changes. There's nothing wrong with opening the fermenter to take a gravity sample as long as you practice good sanitation.
    – Denny Conn
    Mar 16, 2013 at 16:04

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