First AG - and massive calamity...

[VillageBrew]

Was supposed to be doing first BIAB last week (chickened out and did extract/ cereal beer). Went for it today with a Dunkelweizen. Just got grains into strike water and my (very cheap) digital thermometer went beserk. It was claiming the ambient temperature in the utility room was 94°C! Minor panic set in but just carried on regardless. After some guessing, hoping and judging 'by eye' I pulled the mash bag out with relief - the pre-boil gravity was 1.050°.

Boil went off without a hitch and it's now tucked up in the FV. New thermometer needs ordering - grateful for suggestions?

 

[dufresne]

I started a thread about a week ago asking for thermometer suggestions. Should check it out out. I've not decidedly yet!

 

[WestEnder]

I really should get a thermometer for the job. I've bean using a meat thermometer so far and while it seem to work I'm a bit worried about it measuring core temperature given it's designed to measure things no thicker than a pork chop as opposed to six kilo of doughy malt. :)

Digital thermometers that look suitable are dirt cheap on Amazon. Will this suffice is it worth spending any other cash?

 

[ManseMasher]

Thermopens are excellent, but expensive. Ebay digital ones are cheap and cheerful, and sometimes way off. I've got one and it has been fine. I've also got one from Ikea, that works too.

 

[jmh7117]

I use this!

Its mega.

http://www.nisbets.co.uk/hygiplas-multipurpose-stem-thermometer/F338/ProductDetail.raction

 

[Hoppyland]

For anything critical, I reckon always have a backup. A cheap digital thermometer can be fine (I used to use one as a help to keep a check on hatching batches of 30 chicken eggs - a lot more critical than 5 gal of beer!). But, they can suddenly fail. A laboratory-certified mercury in glass thermometer will be extremely accurate - until you knock it onto the floor, when it suddenly becomes useless!
My other suggestion is that you shouldn't confuse "precision" with "accuracy". A digital thermometer is sure to impress, because it gives you a clear reading, apparently with 0.1C accuracy, but as ManseMasher says, they can be well off. So they give you a very precise reading, but not necessarily an accurate reading of the actual temperature. This doesn't have to be a problem - if you have a certified accurate thermometer then use it to calibrate your cheapo ones, then pop it back in a very safe place (and use it as a fall-back if you need one)

 

[Leon103]

I use a glass thermometer and a few of those cheap Chinese eBay ones. My ikea one went beserk on me

 

[GHW]

I use this one or one very similar. Cost about the same. I've never calibrated it but by the same token I've never had any issues wth mash efficiency so it must be pretty good

http://www.amazon.co.uk/gp/product/B00CDOQEBK/?tag=skimlinks_replacement-20

 

[brumbrew]

I've been using a kitchen meat thermometer. Not the best I know. Also have one for coffee so the froth range is in there. They both give different readings. :-( also something I need to look at.

 

[VillageBrew]

I started a thread about a week ago asking for thermometer suggestions. Should check it out out. I've not decidedly yet!

Thanks - looks like similar comments arrived tonight! I like the idea of a 'traditional' glass thermometer as backup/ calibration for a digital one. A spot of Amazon shopping coming up I think...

 

[ManseMasher]

I use a glass thermometer and a few of those cheap Chinese eBay ones. My ikea one went beserk on me

Take it back, get another one. Mine has been fine for over a year....

 

[BrewzLee]

Hi,
Not sure if your digital thermometer is similar in design to mine but I have also had problems half way through a brew day where my thermometer began reading ridiculous temperatures. Mine is a cheap digital thermometer with a probe connected via a wire (from eBay). I was able to repair mine by disconnecting the probe from the thermometer and placing the stainless probe on a baking tray in the oven at 200C for 30 mins (you need to leave the wire hanging out of the oven). After 30 mins I took it out of the oven and could see sugary liquid had bubbled out from the connection between the probe and the braided cable. I let it cool down to room temperature before testing and it has worked fine since.
Hope this helps

 

[Leon103]

Take it back, get another one. Mine has been fine for over a year....

Nearest ikea is 3 hours away. I bought it online and did take pictures to complain but forgot. It was only a few quid so may buy another if I ever go there

 

[VillageBrew]

Hi,
Not sure if your digital thermometer is similar in design to mine but I have also had problems half way through a brew day where my thermometer began reading ridiculous temperatures. Mine is a cheap digital thermometer with a probe connected via a wire (from eBay). I was able to repair mine by disconnecting the probe from the thermometer and placing the stainless probe on a baking tray in the oven at 200C for 30 mins (you need to leave the wire hanging out of the oven). After 30 mins I took it out of the oven and could see sugary liquid had bubbled out from the connection between the probe and the braided cable. I let it cool down to room temperature before testing and it has worked fine since.
Hope this helps

Excellent idea! I'll be testing that tomorrow. Every day a school day.

 

[Hoppyland]

I've never had any issues with mash efficiency so it must be pretty good

This sounds right - but I'm not sure that its necessarily true. Say that your thermometer was 3C out, perhaps reading too high. Then, if you think you're mashing at 67C, its actually happening at 64C. I reckon your mash efficiency will probably be fine. But I'd expect the ratio of fermentable v unfermentable sugars in your wort, and therefore the body of the resulting beer, to be very different.

 

[GHW]

This sounds right - but I'm not sure that its necessarily true. Say that your thermometer was 3C out, perhaps reading too high. Then, if you think you're mashing at 67C, its actually happening at 64C. I reckon your mash efficiency will probably be fine. But I'd expect the ratio of fermentable v unfermentable sugars in your wort, and therefore the body of the resulting beer, to be very different.

damn these really smart people who know way more about this than me.
I'd better calibrate the thermometer then!

 

[Cwrw666]

I use a glass and mercury dairy thermometer of somewhat ancient origins - my wife had it when I first met her which is like 36 years ago. It's in fahrenheit but is great as there's a red line marking pasteurisation temperature which just happens to be mash temperature. I looked on ebay a few weeks ago and there were quite a few exactly the same and at a pretty good price too.

 

[Tony1951]

If people are using glass thermometers, remember that most of them are partial immersion type and are only accurate when dipped into the liquid to the correct depth of immersion. in the case of mine it is 76mm. If you dip it deeper than that it reads higher than the true temperature and if you dip it in less it reads low. Most thermometers have a mark on them showing how deep to insert them. If not, it will be printed in numbers on the side.

I wrote an article on this a good while back.

http://www.thehomebrewforum.co.uk/showthread.php?t=54435

I had a lot of confusing readings with it showing like 104C when the water was boiling and also high and low in iced water depending on the depth.

I have a cheap ebay digital thermometer and it works great as long as:

1. I keep the electronic bit dry.
2. I only insert the first 10mm into the fluid.

If I insert my digital thermometer to different depths I also get inaccuracy like the glass ones. This may account for some of the problems listed above about digital thermometers not reading true. Try experimenting with dipping the tip to different depths in boiling water and see where it reads true. Then stick to that depth of immersion for accurate readings. Mine works true at 100C and 0C (iced water) if I insert it to the same depth, The difference is about 0.25 of a degree C which is plenty good enough for accurate mash temperatures.

 

[JapanBrew]

I'm frustrated about this too. Where is the best place to place the sensor!?!? In the grain? Then you get some insulation and just to guess, seems like wet grain is a great insulator.
Bottom of the wort? But is that the temp, minus take off while passing through the grain?!?
When we say alpha and beta separate at x temp, is that the actual grain temp??? Sorry, maybe a stupid question.... I step mash with a STC1000 and I've always had issues with where to place the probe. And recently I've built a recirculating mash system so maintaining the temp is a big deal. Loose a lot while the wort passes through the pump, the hoses then through the grain.

 

[Tony1951]

Since I know my electronic thermometer is only accurate if dipped in about one cm, I stir the mash up vigorously and dip it in just that much. If I want to check temperature later on in the mash, I do the stirring again because it will obviously cool more at the outside.

On the other hand, people who probably know, often say don't be stirring the mash up too much. I just make sure in the early stages that I have it not too hot and not too cool, and then I put the lid on and pull a good old sleeping bag over it to keep it there.

Cheers.