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BIAB #2 - Status

Well if he dumped in boiling water and the gun read 160 on the surface after a few minutes it may have been hotter for a period 170 will stop conversion but your right it probably wasn’t there long enough. Just thinking out loud again.

I don’t believe it’s the yeast at all. The forced fermentation test confirms that in my opinion. Since there is no further attenuation during the forced fermentation test, that means there are no more fermentables in the wort. The forced fermentation test results show no drop in the specific gravity of the test wort (drawn from the fermenter). So based upon that throwing more yeast isn’t going to do anything. It’s finished there’s nothing left for the yeast to convert.

It’s back to the process and how I check/maintain the temperatures for my mash, temperature accuracy, etc. during the mash process. Not certain when I’ll get back to my next attempt, but I’ll let you know what happens.

As for the temperatures that I recorded, it’s not unusual for the temperature to rise or bounce a little under these conditions. It’s called the transport phenomena and thermal inertia.

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I think it is quite unusual for the mash temperature to go from 152 to 160. I think you need to invest in a good thermometer. I started with a digital and had problems because it read all over the place. Now I use a long stem dial and always hit my temps consistently

I like my Polder digital thermometer… especially the temperature alarm

Similar to the one I had. I found it eratic. I’m sticking to my dial

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I agree @olanwade, it’s not a yeast issue. In addition, I also agree that it’s not a stuck fermentation as your forced fermentation tests gave similar results.

I also agree with @damian_winter that this is likely a recipe issue coupled along with a process error.

Your BIAB. What are you brewing on? A stove top? If so are you leaving the pot on the burner after mashing in? This would cause the mash to continue to heat.

In addition, ditch the infrared temp gun. That is only measuring the temp at that location. I’m willing to bet you a beer that this is likely the issue.

Get a thermopen and take multiple readings throughout the mash. I stir until that reading is similar or the same throughout the mash.


You are right that The bimetallic strip in your thermometer is slower to react than electrical resistance in a digital thermometer. Also my style moves around the pot a bit while yours probably stays put

That’s allot of Cara not surprised at the high FG if thats how much he used in this recipe. I’d suggest closer to 5%

Im just going to be honest. Your first was because 21% carapils and most likely your mash temperature. Iodine test will tell you that conversion of the starches has changed to sugar. Not that your wort is fermentable just that conversion has taken place. With a large amount of crystal/ caramel malts or Dextrine, and higher mash temp will result in a less fermentable wort. Giving you a higher final gravity.



Nah I stir it around a bit. I think the probe on mine didn’t like being submerged in liquid. Your probe may be better I’m just gun shy. Had problems similar to @olanwade

That is something many new all grainers don’t realize.

Second this opinion and the thermapen.

Thermometer wise I would try a few to get an idea if one is way off. Or test by measuring ice water and boiling water. My MT has a thermowell with a probe connected to a PID controller and an old fashion dial thermometer. I tested the mash (after stirring) with a traceable scientific thermometer and discovered the dial thermometer was right on.

Mash temp wise try using the least amount of non-fermentable grains possible and just mash at high 140s. Not ever trying BIAB is there a way to actally stir the mash? I assume the top of the bag is open to do so.

This is perplexing @olanwade Your method seems solid yet a FG of 1.03x is too high.

Like @damian_winter says not surprised at all with +20% crystal malt

I posted this back 2017 and still is great read for the newer brewers here. Calibrating your thermometers and hydrometer.

I stir my BIAB every 15 minutes and it appears to help my efficiency

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Well, I had success with my 3rd attempt at BIAB. I completed my brew yesterday and it’s fermenting nicely in the primary. I was diligent watching my mash temperatures. At the completion I did another forced fermentation and voila the final gravity was at 1.014. I’ve named it my Betsy Ross Amber Ale in celebration of our Independence Day 2019! It should be ready for tasting on/about the first week of August.


Nice read

Betsy Ross had a really interesting life, and like Betsy Ross and her 3rd marriage, your 3rd attempt worked out.

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