Raising kettle volume for thermometer

I mash in my kettle, and my kettle mounted thermometer reads at the 6.5 gallon mark. With 5 gallons of water and 10+ pounds of grain, it close to the level.

[Note - I use BIAB, and may perform a dunk sparge in a separate pot with a small amount of water, after which I SCOOB (Squeeze the Crap Out Of the Bag) and pour in the runnings. This is why I don't have more water in the kettle. Though maybe I should, and forgo the squeeze, just raise, drain, and dunk from time to time, in addition to stirring]

To raise the water level, do you think its ok to add a few metal water bottles (filled with water at the mash temperature, and a little head space), suspended by cords from the side, into the mash, to displace a few liters and raise the wort level comfortably above the thermometer stub.

I will remove these after mashing, and not boil them or sparge them.

Why would this be a bad idea?
What else can I do to raise the wort level a few liters?

I have another alternative, I have a glass vase, that I can fill with water at the same temperature as the wort. That is more of a pain though.

Me personally, I would just move the thermometer down near the bottom and it won't even be an issue, then plug up the original hole. But if you really want to leave it wear it is, anything you can put in there to raise the level will suffice provided it's relatively clean and won't leech chemicals into the wort.

I'd rather not have to move the thermometer down an inch - (punch a new hole, and fill teh old one) but that would work.

Any other ideas to fill up the volume a little that wont damage anything or cause off flavors.

Marbles?

Glass jar or hops bag with marbles

Blue_Monkey said:

Glass jar or hops bag with marbles

Click to expand...

How do you use a glass jar?
Please describe the exact steps, starting with a pot of 75F degree water.

If you put a lid on it, and raise the water temperature, you risk bursting the jar.
Do you instead dip the jar in when the water is at 152F? Filling it and sealing it?
How do you get it out for the boil, attach some kind of cord around it that hopefully stays on?

You could use a hand held thermometer. That would give you a better idea of what the temp is.

mburnett274 said:

You could use a hand held thermometer. That would give you a better idea of what the temp is.

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I could, but it is useful to actually be able to use the kettle mounted thermometer. I will use my Thermapen, but I'd also, like to use the kettle thermometer as a rough gauge, to give me an idea if the temperature has dropped over time.

Maybe marbles are not a bad idea.... not sure how they will hold up

Can solid glass can be boiled without any problems?

ArcLight said:

How do you use a glass jar?
Please describe the exact steps, starting with a pot of 75F degree water.

If you put a lid on it, and raise the water temperature, you risk bursting the jar.
Do you instead dip the jar in when the water is at 152F? Filling it and sealing it?
How do you get it out for the boil, attach some kind of cord around it that hopefully stays on?

Click to expand...

No doubt the idea is to just use the glass jar (or hop bag) to hold the volume-displacing marbles. I don't think "jar glass" in general would be a problem surviving a boiling water bath, but it would probably be prudent to stick with jars that held foods that had to have been heat-pasteurized to begin with.

You could retrieve the jar with tongs, or your cord.

The hop bag loaded with marbles is probably the better choice of the two, but if it was me I'd move the thermometer down a couple of inches and install a plug in the old hole...

Cheers!