High FG - Should I reuse this yeast?

[Ben Matthews]

Hi peeps. Wondered what peoples opinions on this are? I bought a fresh pouch of wyeast Belgian Ardennes about 6 weeks ago. Put it into a couple stepped starters with 1.040 wort with yeast nutrient in. Pitched most of that into my Belgian Blonde (The post on the forum where I thought it smelled of piss and turns out it was some of the leaked krausen got under the fermentor.), and kept some of that starter back and put it into the fridge. The yeast did very well in that Belgian Blonde I did, got it nice and dry 80% attentuation. Really great beer.

3 weeks after I put that yeast in the fridge I decided rather than make a couple starters for my next Belgian Blonde, I'd make a small 4 litre drinkable batch of Belgian Pale Ale as the starter with the plans of pitching the yeast cake from said 4 litre beer into my 12 litre Belgian Blonde sometime soon. Recipe for the BPA is:

960g Pilsner malt, 60g Caramunich 2, 20g Biscuit Malt.
6.5g EKG at 60 mins, 1.5g EKG at 0 mins.
Mashed at 67/68 degrees C. Hit expected OG of 1.058
Added Wyeast nutrient.

It went into the ferm chamber with an american wheat and was pitched fairly cool by accident at 15 degrees C. This was then very slowly increased over 2 weeks to about 20 degrees C. Airlock stopped around 7 days in and then left well alone as still some krausen floating around. That has only just pretty much gone at about day 18. Last night I bottled the American wheat which was at its FG. I went to bottle the BPA expecting such a small batch to have finished but the gravity is pretty high still. 1.021 I think today. I've cranked the ferm chamber to 23 degrees now and am obviously going to monitor the gravity for a couple of days. The hydrometer is now floating in there so easy to keep an eye on.

I'm not all that fussed if it finishes high as its only a small batch and I will still drink it for sure. My main concern is whether or not I use the harvested yeast for my next Belgian Blonde as I don't want to be stalling on that batch as it needs to be nice and dry. The last batch tastes amazing. There's no reason the yeast should be stressed or tired out? It's only been through a couple starter cycles and then this small batch BPA with relatively low ABV. Everytime its had a dose of wyeast nutrient and been fermented at a controlled temp. I would love to get one more batch of Belgian Blonde out of this before I retire it and get a new pouch as its just so expensive buying a fresh pouch every batch.

Thanks in advance peeps.

Ben

 

[strange-steve]

Did the SG drop any further? Remember that this yeast is a bit less attenuative than other Belgian yeasts but 64% attenuation is definitely low. There are many variables which could have caused it, but personally I would probably resuse it, making sure of mash temperature, pitch rate, aeration and so on.

 

[Ben Matthews]

Hi Steve. Off to top of my head I think it went to 1.019 and then stopped. I bottled it. It didnt taste overly sweet to be honest. It is a low attenuating yeast although I did get 80% out of it on a Belgian Blonde but that did have some simple sugar in. I've kept the yeast but I did find an unopened pouch in the fridge so made a couple of starters and used that instead. I've made the same Belgian Pale Ale again alongside my new Blond so I'll see if it gets to a lower FG this time.