unfermentables

[cwrw]

What could be a contributing factor to a wort of 0.130 not being accessable to yeast action in normal brewing conditions?
I've explored via different routes of waking up two lagers (see my entries under 'the definition of life') brewed with a bohemian strain, and have finally added DME to the mix, which shows good signs of yeast activity. Therefore it leads me to conclude that there must be a a load of unfermentables in there instead of fermentables. Is this true, and if so what's gone wrong to make two beers stick (one at .24 and the other at .30 gravity) during my mash (I presume)?

 

[jonnymorris]

What are you mashing? What temp and how long? Do you mash out?

What temp are you fermenting at?

Yeast viability could be a factor with your stuck brews... what type do you use, do you rehydrate if dry or make a starter if liquid? How old is it?

 

[cwrw]

mashing lager malt with addition of munich, temp 66.5- 70 for 90 minutes, sparging at 68c, fermenting at 10-11c. I thought along the yeast viability issue the first time round, as others have pointed out to me that I should have made a starter with my smack pack - lesson learnt.But this would not be logical, as when there is the addition of fermentables, there seems to be a corresponding yeast reaction/activity, but the brews do not go beyond their 'stuck' values values prior to their addition :wha:

 

[wilsoa1111]

well heres what i think...
1: ur mashing v high at ur highest estimate and moderately high still at the low end-

2: most thermos tend to be a bit off unless u have a proper thermo pen or a well calibrated thing so could be ur mahing higher...

3: for lagers a starter is vital unless u want to risk it stalling- pos whats happened here (a starter aims to increase the health and the number, health being important which a quick ferment at a nice abv does nicely,
remember u are asking alot of the few cells at the end to clear up the offproducts and the big hard to digest stuff (in a harsh enviro) so basically u need to increase the number of cells at the start in the hope enough make it to see the job through

 

[cwrw]

Many thanks for the reply - I think you might be right regarding the temps being too high, as I try to establish a place for them to drop due to my massive cooler mash tun absorbing so much heat. Never had an issue with not making a starter before, but will take this onboard :thumb: