Mash Temperature and fermentation temperature

[zoenryan]

Hi - first congratulations on your software - it must be good 'cos I paid for it in recognition of all the hard work that went into it. I have been extract brewing for years and decided to make the jump to all grain.
My new mash tun (insulated cooler) looses 1 degree (C) every 20 minutes - I checked this with 65 degree water before starting. Does your software correct for this  or should I be opening it it up after 45 minutes and adding hot water (note you have a tool for calculating the addition) to maintain the mash temp as specified after - say 40 mins when it will have lost 2  degrees ?
I pulled a load of recipes from your recipe cloud - great tool by the way . The recipe recommended White labs WLP005 British Ale yeast and a fermentation temperature of 19 C
I created a starter 24 hours prior and pitched at 19 Deg - and - nothing . After 2 days of no activity at 19 i re pitched with a re-hydrated pack of Danstar Nottingham - and it took off.
When checking the data on the WL website - WLoo5 is recommended for a temperature of 18 - 21 deg . It could be that my thermometer is 1 - 2 deg off - but even so had I realized that the optimum temperature range for the yeast is so close to the recipe temperature - I would have gone for Nottingham straight away - as it has a wider temperature range.
Can the temperature data for the yeast be found in BrewSmith - and / or an alert put in if the selected fermentation profile is outside or close to the recommended range for the Yeast ?

Co-incidentally, the second recipe I tried  - I used Nottingham re-hydrated as per the Danstar data sheet. It too failed to start after 24 hours so pitched again with Nottingham and it fired up - now going great guns fermenting.

why the 24 - 48 hour delay ? - both were chilled to 19 deg before pitching . Should I be aiming for  - say 21 deg during chilling and pitch  - and then allow to fall to 19  - ?

appreciate any advice

Regards

 

[Mofo]

I've encountered similar difficulties with slow fermentations. I know now to take both a gravity and pH reading before assuming the yeast have failed. Yeast don't fail unless you've done something really wrong. If the gravity reading is the same as it was pre-pitch but your pH level has dropped half a point or more then it's started, albeit slowly. If neither has moved, it's time to re-pitch and re-oxygentate.

Chris White and Jamil Zainasheff's book Yeast is worth buying for its troubleshooting section alone...

Based on the info you've provided, you might look at your pitching rate, oxygen level and yeast health. If your OG is higher than 1.050 and you're pitching dry yeast you'd want to rehydrate and pitch two packets. If you're pitching a vial of White Labs you want to make a 1.5 liter starter to get the best propagation rate. Then make sure the wort is well oxygenated. Shaking the fermenter or pouring back and forth between brew pot and fermentor prior to pitching can help. Better still, use an air pump from a fish tank with an air filter and sintered stone for 30 or 40 minutes after pitching at the high end of the temp range. And be sure you're starting with healthy yeast. As White Labs vials near their "best before" date they lose a lot of viability, especially if they haven't been stored properly.

Another possible cause might be if you had an excessive amount of trub trapping the yeast on the bottom of the fermentor. Highly flocculent British ale yeast can get buried under break material. Agitate the fermentor every 15 minutes for the first several hours after pitching.

 

[zoenryan]

Thanks for that - I guess as these are the first 2 all grain brews I have tried I was a bit nervous and impatient - what it did cause me to do was download the data sheets on the yeast.

I have read a lot about aeration and how important it is . however - if you read the Danstar data sheet it says aeration is unnecessarry !
All it has taught me is the importance of actually reading all the available data.

Kegging the first one tongiht so first trial this weekend.