Losing a ton of heat during mash in

[bandt9299]

What is the difference if I pre heat my mash tun and heat my strike water to 166 or skip the pre heat and heat my strike water to 173. I usually lose only 1-3 degrees so I'm still wondering why this preheat step is necessary. No huge difference here. For me anyways.

 

[iaefebs]

What is the difference if I pre heat my mash tun and heat my strike water to 166 or skip the pre heat and heat my strike water to 173. I usually lose only 1-3 degrees so I'm still wondering why this preheat step is necessary. No huge difference here.

I think we are talking about the two different methods of pre heating the cooler. Some like to dump a gallon or so of heated water in the cooler and then dump it out and add the strike water. I agree that it is unnecessary. I heat my strike water to the temperature that accounts for all the temperature losses. You lose temperature any time you have to warm something up. Be it grains or your cooler. Whether you realize it or not that is what you are doing. You are not skipping the pre heat, you are accounting for the loss with the higher temperature strike water.

 

[Krovitz]

I preheat with my strike water. I usually add it to the mashtun at around 185* and wait 30 minutes. The temp drop is between 14* and 17*. I'm still working out my temperature kinks but this is definitely a very important step for my set up.

 

[bandt9299]

I just like to brew and teach the simplest way, in my opinion anyways. If you can simplify your brew day start to finish you can save time and energy.. I have brewed many times on the local brewpub 7 BBL brewhouse and we never preheated the tun. It was hot water mixed with room temp grain and you live and learn. There is no one perfect method that works right for everyone. But to me it's the method that is the easiest to teach and learn.

 

[iaefebs]

Whether you know it or not the 7bbl local is taking into account the grain absorption temp. This stuff is not alchemy. It is science. I'm sure someone can come on here and explain the heat loss in joules, but the main idea here is to help the homebrewer. The confusion here is the term pre heat. You have to account for all energy loss by grain absorption and mash tun loss. No if, ands, or buts.

 

[Hawaiibboy]

So I know my previous statements might not have helped but this might:

I was watching the equipment setup video for BeerSmith 2.x and it seems that based upon the mash tun construction material you'll have different temp losses to the MT itself. In addition to this loss your biggest factor is time, I'm not sure if BeerSmith takes into account air temp that you are brewing in. This can cause big losses in temp over time, as some of you have described.

My suggestion would be to grab a free trial version of BeerSmith or another full featured program in and plug some numbers in to see what your potential losses are/could be.

I personally use iBrewMaster on my phone and have been able to get decent results for my BIAB temps. I am also brewing in 68-78F weather and using a s/s kettle to mash and boil in.

 

[Mojzis]

I have beersmith and have added the specific heat of the tun to the calculations. From everyone's comments i'm sure its from not pre-heating with my strike water. By doing that i'll get the tun all the way heated and have less time the water comes into contact with the relatively cool air.

 

[Hawaiibboy]

I have beersmith and have added the specific heat of the tun to the calculations. From everyone's comments i'm sure its from not pre-heating with my strike water. By doing that i'll get the tun all the way heated and have less time the water comes into contact with the relatively cool air.

I personally like the heat all your strike water to about 10-20 degrees higher then calculated and then just wait for it to drop to your calculated strike temp based upon the grain quantity and grain temp. That was how I used to pre-heat my cooler in OR throughout the year and it seemed to work well.

Good luck!

 

[LandoLincoln]

I did a test with my mash tun today using only water to see how well it would retain heat. I had heating issues using it for my first all grain batch. Temps dropped too low.

I did a test with a little over 3 gallons. My "strike" temp was 170F. I did not preheat the Lowes circular style cooler.

I closed the lid when it was 165F. In one hour the temp went from 165F down to 153F. Again using only water. Clearly not good.

Now the most obvious question is, does the lack of grain in the cooler speed the drop in temp? I assume the grain itself would help act as insulation and help retain that heat. But by how much?

If not, not sure what else I can do. I did not cover it with a blanket. That might help a couple degrees. The outside weather here today is fine, 68F. I've read people have tried to insulate the lid with spray foam insulation. Maybe I can try that.

Put a layer of aluminum foil on the top of the mash before closing up the lid. You'll be amazed how well the heat stays in with this trick. Sometimes my end-of-mash temps are a half-degree higher than before I closed the lid. "Uh...what? How the hell did THAT happen?"

 

[Mojzis]

So I had some free time this morning and decided to see how adding strike water first works. I didn't add any grain, I was just testing to see what temps I need to strike/pre-heat the tun with so this weekend I can be in the ballpark. My tun was around 60 (should have taken exact temp) and my strike water was 2.56g at 185 (meant for a 5g batch, 8.20 lbs grain at 1.25 qt/lb). It dropped to 166 after 1.5 min and down to 163 in 4.5 min. Looks like I need to go higher. I'm going to try this a few more times for more data.

 

[iaefebs]

That's a lot of heat loss. But again it's 2.5 gallon in a 60° 10 gallon cooler. I don't know if I would want to put more than 185° strike water in a cooler for fear of warping. Maybe that's why some people pour a gallon of hot water in first and dump. Since you are going to do some tests how about trying 1/2 your strike water @185° wait 5 minutes and add the other half.

 

[Mojzis]

Yeah I know 2.5 is very little, but I do mostly 5g batches. I could always bump my mash back up to 1.3 qt/lb. I've been up to 200 without any warping. I'd rather not have that happen though! I did run another test after the first. My thermo read 120 in the MT, struck at 185 and only lost 13 degrees initially. I'll try using half and half next.

 

[Mojzis]

Brewed over the weekend. Didn't have time to run anymore tests. I estimated I'd lose 27F during the mash in. I lost around 32 15 minutes into the mash. MT was 65F and my strike water was 182. I had the pot of boiling water going and bumped it up to 155 like I wanted. I'm thinking the amount of water for a 5g batch is too small. I'd like to add a piece of exterior, reflective coated insulating styrofoam on the top of the mash or screwed to the inside of the lid. Hopefully that will trap some extra heat in.