Thermometer fail on PM IPA, now what?

[Pelican521]

Hi all, I just wanted to get some opinions on what to expect with my IIPA that I had some issues with that I brewed 4 days ago. It was a partial mash (6 lbs grains) with a projected OG of 1.075. My mash consisted of 2 lbs 2 row, 2lbs Vienna, .25 honey malt, .75 lb quick oats, .25 lb crystal 40, and .75 carapils, and 1.3 oz of acid malt to help with mash ph since I used Poland spring water which is very soft. Also added late in the boil was 4 lbs dme and 1 lb of cor sugar.

I used 8.5 qts for my mash which came in at around 151 after strike water. I don't have a ph meter and I know the strips aren't that reliable but it looked just over 5.0 ish when my sample was cooled.

When I did my boil I noticed my dial thermometer was way off showing my boil around 220 degrees! So approx 7 degrees made my mash temp around 144. My OG ended up 10 points lower at 1.065. If it ferments out to the projected 1.011 it will end up with around 7.2 abv or so.

The attempt of this IIPA was tweaked a sip of sunshine clone with lots of late hops and whirlpool plus 4 oz of dry hops.

Any idea on how these issues will effect the final product? Taste/mouthfeel etc?

Thanks in advance.

 

[m1k3]

I've done 60 min mashes at 144F... works just fine. But then again I usually use more than 2 pounds of base malt.

 

[Pelican521]

Yeah hoping it won't effect too much, this had 4.25 lbs fermentable grains, probably about 1/3 of the sugars or so. Wasn't sure if the low ph would mess things up with the low temps.

 

[MagicMatt]

... and 1.3 oz of acid malt to help with mash ph since I used Poland spring water which is very soft.

I don't have a ph meter and I know the strips aren't that reliable but it looked just over 5.0 ish when my sample was cooled.

This seems like a red flag. The way I understand it usually only "hard" water (more accurately, water high in alkalinity) would require acid malt. If you're using soft water, there probably isn't much of a need for it, and your (non-scientific) reading of 5.0 would indicate that the pH was driven too low. It will probably still be drinkable, maybe even great, but that just caught my attention.

 

[Pelican521]

Yeah, the acid malt was suggested by my LBS. I think next time I'll leave it out until I check my mash ph. Then add a little at a time if needed.

On the other hand, I checked my thermometer in a glass of ice water that I had in my fridge for an hour and it was exactly at 32 F. From what I read, this is the best way to test a thermometer's accuracy. Not sure why it read so high in boiling water... Stumped.

 

[joshesmusica]

Depends on the grain bill as to whether or not you would need to add some acid in soft water. If it's all light malts, you will more than likely need some. Even in RO water you need to add some acid for lighter grain bills.

Boiling likely won't even be 212F where you are (at sea level it's 212) so it's probably even more off than you thought. Likely by around 10 degrees or more while boiling. I would check it against another thermometer in order to be sure. I doubt that how much it's off will necessarily be logarithmic either, so trying to guess how much it's off at mash temps will always yield off results.

With this batch, you might have a slightly lower FG than expected, but since it's PM, I don't know that it will make as much of a difference as if it was all grain. If your goal is eventually all grain, it's good to get these kinks out of the way while you're still supplementing with extract.

 

[JohnSand]

I think it will be fine. I've had mash temps all over the place with good results.