Fermenting issues

[LOst]

Hello,

I am fairly new to brewing, have brewed 4 batches so far. My last 2 brews however have stopped fermenting half way through.

The first I used a Morgan's Canadian Light, 500 g dextrose, 500 g light malt and 24g Amarillo hops. This one started at 1040 OG and after 17 days was at 1014. The second is a Morgan's Australian Lager, Morgans master malts extra pale, and 12g finishing hops. Again, started at 1040 OG and 4 days later is at 1018, and has been reading this for 3 days now.

The first two batches I made worked out alright, why are these ones stopping? The ambient temperature is usually between 19 and 23 degrees, I clean the fermenter and mixing spoon with sodium percarbonate 1 tblsp / 3L water solution, and sanitise with 1 mL/L iodophor solution, and allow to drip dry.

Any ideas?

Cheers
Lance

 

[MaggieO]

Seems to be a problem with kits that come with small amounts of yeast. 6-7 grams really isn't quite enough for a 23 liter batch though it does seem to work for a lot of people.

If you have a long spoon you can sanitize it then give the beer a stir, very gently. Sometimes getting the yeast stirred up can help.

I've heard of people mixing up some sugar syrup, white sugar and water, and adding to to the fermenter to get it going again. Be sure you boil it and cool it before adding.

Rehydrating the yeast before pitching seems to reduce the chance this will happen too.

 

[LOst]

Thanks. I tried stirring it up to no effect. I'm just going to bottle it up and try again, might rehydrate the yeast this time though. Do you think there will be enough yeast to carbonate in the bottles?

 

[philrob]

Definitely underpitching, in my view.
Use a proprietary yeast which has been stored properly (ie fridge) or grow up a liquid yeast.
I brew 25 litre batches, and use liquid yeast but still always grow it up on the stirplate.
And properly aerating is important. I inject pure oxygen for 60 seconds.
All of that ensures I always get apparent attenuation at the top end of, or better than, the specified range.