Can I take a hydrometer sample using a glass?

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Feb 29, 2020
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Quick question: Would I be able to take a sample for my hydrometer by dipping a glass which was cleaned by the dishwasher into the fermenting vessel?

I would then pour the glass into the hydrometer vial

You certainly can, but it does introduce the possibility of microbial contamination. Whether that matters depends on your process.
yeah i would spray it down with starsan first. or if thats not an option you could boil a mason jar to sanitize it and use that.

Okay nice, I have a 1 litre spray bottle and some StarSan, how should I mix this up for this spray bottle? Also don't I need to clean (sterilise) it first before sanitising? That's a great idea with the mason jar, thanks!
Whatever you use the best practice is to sanitize it. You may also want a way of taking a sample that minimizes splashing which increases oxidation.
Could I just dip only the hydrometer into the fermenter and check it that way? Does it really need to be clean?

I last used it for beer and quickly cleaned it with warm water after use
it needs to be sanitized, but you could do that after sanitizing it. depending on the size of your spray bottle you would need very little star san. its 1oz per gallon so if your bottle is a quart then you would need 1/4 oz of star san. spray it down, wait a couple minutes and drop it in. save your bottle of star san for the next time you need it. i keep a spray bottle of it on hand at all times.
Thanks guys, really appreciate it. But just to be clear, If I used a glass from the dishwasher does that count it as being clean? (sterilised). (I will still sanitise it after)

and also: does the hydrometer need to be sterilised (cleaned) or can I just spray a little starsan on it and it will be fine to just drop in the fermenting vessel?
Clean, sterile, and sanitary are different things.

Clean means free of surface residue.
Sterile means completely free of microbes and spores. We don't generally worry about sterility because it's both unnecessary and impossible to achieve.
Sanitary means free of significant amounts of potentially contaminating microbes.

Wine frequently already contains wild microbes, so sanitation is often a moot point. Furthermore, wine is generally highly resistant to the effects of contaminating microbes when a good basic process is used (i.e. oxygen avoidance and sulfite). So, using an unsanitized glass to draw a sample really isn't going to be a concern most of the time.

As I mentioned, only clean surfaces can be sanitized. Residue can harbor microbes.

Measuring s.g.:
I also recommend a turkey baster, or better yet, using a vessel with a spigot.
I wouldn't recommend putting the hydrometer directly in the wine for several reasons, the most important of which is that it's difficult to read.

Regarding oxygen:
Splashing or not, if you open a vessel to take a sample, almost all the oxygen exposure will depend on the amount of headspace in the fermenter.

Regarding oxygen:
Splashing or not, if you open a vessel to take a sample, almost all the oxygen exposure will depend on the amount of headspace in the fermenter.

And although I don't know how much you can protect against oxygen getting into the head space, I always tip the lid from one side, dip my sanitized measuring cup in, and close the lid as quickly as possible (very gently - minimal splashing). It's probably open about four seconds. I don't delude myself into thinking I've eliminated oxygen, but it's minimized.
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