Strike temp

[Scooby]

There seem to be quite a few posts recently where the subject of preheating the tun and strike temp is mentioned.

On typical brew I preheat the tun with a kettle full of boiling water and leave for 15mins, drain and add 15lt of water at 80c that settles to 78c after filling, I dough in 5kg of grain at room temp (2.75/1) and get close to 68c a drop of 10c

It seems that the most common strike temp mentioned is 72c to achieve an mash temp of 67c, a drop of 5c.

I know there are many variables like thermal mass of tun, grain temp and ambient temp, but is that the explanation for the wide difference in temp drop?

What temp drop do you guys experience when mashing?

[Andy]

I preheat my coolbox tun with boiling water and then use beersmith to calculate strike heat. Find it's bang on the money - typically 72-74 degC depending upon mash profile.

[Dirty Davey]

I usually aim for around about 72-74C depending on how thick my mash is.

[Scooby]

Hum... must be a quirk of my system or I'm no fully preheating the tun, a kettle full is not very much so that may be it

[awalker]

Hum... must be a quirk of my system or I'm no fully preheating the tun, a kettle full is not very much so that may be it

I used to dump a kettle of boiling water in (kettle is about 2.5 litres)

But it did not quite preheat for the strike temps I got from beersmith.

I now have a large pot of boiling water I throw into to preheat, and thats about five litres. Now I find like Andy the Beersmith temp is always bang on.

[Andy]

I add two kettles worth to the tun, fit the lid and leave for 10-15 mins.

[bitter_dave]

I don't heat the mash tun, but I do add the water a bit hotter than wheeler suggests - about 80c rather than 77c.

I wait until the water is bang on 72 c, then stir in the grain, and it always seems to stabilise at 66 c - I'm always amazed at this.

[Scooby]

Cheers all.

Not a problem really as 'it works for me' as they say. I just seemed to be out of step with the rest of you.

I reckon the drop in temp is due to adding the grain and heating the tun as I dough in.

More care in preheating the tun is called for. I'll try your idea DaaB, fill the tun full at 80ish and leave to heat then return water to the HLT until required amount is left in tun at 72-74c

[Gurgeh]

I have previously added 75C water to my tun with the grain already there. just stir in the water as it all becomes fluid enough to do so. settles at 66C.

Last time though I tried it the other way around - putting the water in first. I had my HLT at 80C, so that I could afford to lose some heat before doughing in, but found myself having to take water out of the tun and heat it up more as by the time I came to dough in i was down to 71-72C. Really frustrating! I guess it was because heat was being lost by dropping it. perhaps a bit of tubing would have retained some heat.

I'll be switching back to my former technique, next brew. I reckon on that being more gentle on the enzymes anyway...

[SteveD]

I add two kettles worth to the tun, fit the lid and leave for 10-15 mins.

Same here, with a coolbox. I use about 2.5L/KG and find that 72-74c will give about 65-67c in the mash wether underletting or adding grain to liquor.

Phil, I remember you saying you needed a higher strike heat when underletting. That'll be because you're not preheating the tun then, whereas if you run the liquor in first and let it settle to strike heat before adding grain, you are.

[Vossy1]

80 deg c liquor into the cold stainless tun gives me 65 deg c once the 10kg of grains been added

Don't know what the strike temp is because I've never measured it...I'll have to do this next time, though I wont be altering it based on the findings...unless it has something to do with the haze issues I've been having....which may be possible

In which case I may well take to adding the grain at 70 deg c and then letting the mash settle, starting the recirc pump and bringing up to temp this way....we'll see

[DRB]

72 for me.

[Seveneer]

Phil, I remember you saying you needed a higher strike heat when underletting. That'll be because you're not preheating the tun then, whereas if you run the liquor in first and let it settle to strike heat before adding grain, you are.

Yep, that's right. I used to go with 80C or there abouts with an uninsulated stainless mash tun. I've wrapped a very thin layer of insulation around it now and aim for about 73C. This gives me a mash temp of 67C these days.

/Phil.

[SteveD]

80 deg c liquor into the cold stainless tun gives me 65 deg c once the 10kg of grains been added

Don't know what the strike temp is because I've never measured it...I'll have to do this next time, though I wont be altering it based on the findings...unless it has something to do with the haze issues I've been having....which may be possible

In which case I may well take to adding the grain at 70 deg c and then letting the mash settle, starting the recirc pump and bringing up to temp this way....we'll see

If you don't let it drop below 77 deg before adding the grains it could be. Why don't you bring the temperature up using the HERMS, it wont hurt at all?

That's what Phil (Seveneer) does. Strikes at a 'normal' strike temp then recirculates it up to the mash temperature he wants. Sweet.

....ahh I missed his post! That's what you did when I was there, anyway

[Vossy1]

Right I see

Well you can forget covering up all that lovely shinyness Might as well have bought a black placcy bin if I'm gonna be covering it up

Next question.....too high a temp has obvious side effects, what about too low a temp for mash?