Two questions

[jjs]

First, what's wrong with my hydrometer? I'm making a lager so I check the gravity 3 times a day because I like to worry. This morning it was 6.4 P @ 53 Degrees in a graduate. I left the hydro in the cyclinder and now it's 5.9 @ 64 Degrees two hours later. It can't be CO2 or temp. Is it fermenting in the tube like that? Just curious.

Second, I have a Homark 1998 beer engine that has been dormant for a few years and was put away dirty. (I'm new here) Any suggestions on how to clean it? I ran some 150 NaOH trough it. Gross, gross, gross.

[sbradt]

No reason that it wouldn't continue to ferment in the cylinder. It should still have plenty of yeast unless you make a practice of filtering your samples. Also, you probably aerated it nicely when you did the first reading. As it sat on the counter getting warmer, that lager yeast started working faster and I can easily see .25 P/hour as reasonable. The real question would be where the gravity was in the tank two hours later. Essentially what you did was a crude version of a forced fermentation.

[Alex T]

Hey,

Wouldn't that just be the difference in temperature causing you to get different readings? I thought that readings need to be completed at the calibrated temp of the hydrometer (20degC I think)...... So two readings at two different temps can't be directly compared (unless you have a correction chart).

Alex

[beertje46]

I agree with sbradt, there will be a change as the beer is still fermenting. I think Alex T is correct. jjs, does your hydrometer have a built in thermometer with a correction scale? Ours have built-in merc. thermo's reading in degress R. Put the hyro in your sample, read gravity, pull out, read correction off the scale. There is no brand name on ours...

[Moonlight]

Yes, I also agree it was likely more fermentation...
Also, if bubbles form under your hydrometer, it will float ever so slightly higher. Give it a spin to fling them off. I would recommend getting a temp. correction chart for your hydrometer. I swore off the cool hydrometers with the thermometers built in, as with as often as I break them, it got too expensive...
Just slip in a baby bimetal thermometer in the sample tube. Remember to calibrate the thermometer often as dropping it on the floor once could knock it off a few degrees and your gravity will be off from that.

As for your beer engine, yes, running some caustic or even beer line cleaner through it should be sufficient. Just make the hot solution in a bucket and suck it through as if it were beer. The older beer engines had brass guts, the newer or rebuilt ones are stainless inside. Be a bit more gentle on the brass, like avoiding chlorinated cleaners.