First biab

[dbaker1202]

I brewed my first all grain beer yesterday. It went well I think, ended up with 21 litres of 1.056 wort, which ended up being 65% efficiency. Just a few queries.
When measuring temp for the mash I got a lot of varying results depending on where I had my thermometer. I use a digital one with a 200mm probe and when I placed it all the way into the middle of the mash without any stirring I was reading around 63 degrees, reading after mixing up the mash was 67 and reading up at the top of the mash was more like 71. My water temp at mash in was 69 and I used 5.5kg marris otter and 300grams medium crystal. So where do people measure there mash temps??

 

[boybrewer]

Well if you add up your numbers and then average them out you will get close to the required temp range that is 67* C . As long as you get close to the required strike temp it will be ok as you will lose a degree or two over the mash time . Don't worry too much about it as you will still make great beer . Try sticking the thermometer into the wort rather than the grain . As it is the wort temp that you need to know more so than the mash temp , for you will invariably get hot and cold spots in the mash . That is why I use a HERMS for I want to know what the wort temp is as the mash temp will lag behind and as you said one spot is hotter or cooler than another .

 

[dbaker1202]

Ok cool thanks, if I'm aiming for 66 degrees with 5.8kg of grain at room temp, about 17 degrees what strike temp should I be at? Is around 69 degrees close enough? I actually put the element back on for about five mins after I mashed in and took all the varying temp readings. Thanks for the heads up on the wort temp as opposed to the middle of the grain, should I maybe get a thermowell put into the base of my pot then?? That would definitely take wort readings then hey??

 

[dbaker1202]

Also I should be able to figure out how close I was with my mash temp when I get my fg reading hey??

 

[Drewski]

Thinking of getting one of these anyone have thoughts.. http://www.ebay.com.au/itm/181652223462?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

They are a glass spirit thermometer.

 

[starships]

Do you have batteries in your thermometer?

 

[wombil]

What for?

 

[contrarian]

Ok cool thanks, if I'm aiming for 66 degrees with 5.8kg of grain at room temp, about 17 degrees what strike temp should I be at? Is around 69 degrees close enough? I actually put the element back on for about five mins after I mashed in and took all the varying temp readings. Thanks for the heads up on the wort temp as opposed to the middle of the grain, should I maybe get a thermowell put into the base of my pot then?? That would definitely take wort readings then hey??

A thermowell will still only measure one point in the mash and could end up being a snag for your bag. To get a more accurate temperature reading just give the mash a good stir before measuring. There will always be warmer and cooler spots but it should give you a good average.

FG might give you some indication of mash temp but there are a lot if other variable as well including the attenuation of a yeast. There's a range for each yeast and where you sit in this will be dependent on yeast health, pitch rate, oxygenation etc etc.

So there's a relationship between FG and nah temp but I don't think it would be causal enough to work backwards accurately.