Refractometer

Found a decent site with all the RHB models and their respective specs... Sorry, I should have done a search before asking...

The RHB-90ATC would be great for mead making (I could have used that last year!) and the RHB-32ATC seems like it would be pretty good for common wine making...

Jon.

The sensation of sweetness varies with acidity and alcohol level, and becomes noticeable at about 0.75-1% residual sugar. Port wines typically have 9 to 10 percent residual sugar, and alcohol levels of 18 to 20 percent. "Specially sweetened" Concord wines have about 36 % sugar, and taste like something one might put on pancakes.

From what I understand, a refractomer is only accurate on unfermented juice.

Just curious-I don't see Jack Schmidling's original post concerning refractometers. Did it appear in the list of posts to r.c.w. on November

2, 2003? Bill Frazier Olathe, Kansas

Bill, here is the text of Jack's post. For some reason it doesn't appear in the archives. Negodki.

Hello Jack - I didn't see your orgininal post so Negodki was nice enough to post your questions. That's a great price for a refractometer. Your boil and replace technique is interesting and will probably get you close to the actual SG. Why not do some side-by-side tests and report back.

With respect to sweetness The American Wine Society suggests that a sweet wine should contain 3.1 to 6% residual sugar (specific gravity 1.012 to

1.024). Of course, perceived sweetness depends on your taster.

There is a method and formula that may allow direct use of a refractometer to measure specific gravity of a fermenting must. This formula was proposed by Louis Bonham on the HBD back in 1999. I worked with the formula a bit years ago but I'm not sure how good the calculated SG agrees with the actual SG. Again, some experiments would be in order.

BTW, my grain mill is still going strong in it's third year. Nice machine.

Bill Frazier Olathe, Kansas

Louis Bonham's equation for the specific gravity calculation is given below:

SG=1.001843-0.002318474(OG)-0.000007775(OG^2)-0.000000034(OG^3)+0.00574(AG)+

0.00003344(AG^2)+0.000000086(AG^3)

Definitions: SG estimated specific gravity of the sample ^2 = squared OG Original gravity of the batch (in Brix) ^3 = cubed AG Apparent Gravity of the sample (in Brix)

That's what I have always heard as well, but check out this article on using a Refractometer in all stages of winemaking:

-David

Is that why I haven't seen anything about mills from you in a while :-)

You may want to check if somehow a 'X-No-archive: yes' is being placed in your headers or the first line of your posts. This will prevent google (and possibly others) from archiving your posts.

Andy

Andy, These are the headers from Jack's original post, which did not get archived (nor did it show up on Bill's newsreader). [I save received newsgroup messages locally for 7 days, which is why it is still available to me.] I don't see anything in the headers that would keep it from posting. Do you?

Path: sn-us!sn-xit-01!sn-xit-09!supernews.com!newshosting.com!news-xfer1.atl.newsh osting.com!uunet!dca.uu.net!ash.uu.net!spool.news.uu.net!not-for-mail From: "Jack Schmidling" Newsgroups: rec.crafts.winemaking Subject: Refractometer Date: Sun, 2 Nov 2003 12:20:52 -0600 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Lines: 31 Message-ID: NNTP-Posting-Host: 209.172.154.13 X-Trace: 1067797624 17172 209.172.154.13 Xref: sn-us rec.crafts.winemaking:110116

Thanks for the link, David. Great to be able to look at the results from an actual comparison.

Interestingly enough if you look at their spreadsheet, the biggest discrepancy between hydrometer and refractometer is at the beginnings of fermentation before much alcohol has been produced. Their notes suggest that this may be due to the excessive foaming during this period making it difficult to get an accurate hydrometer reading (couldn't they have driven off the CO2 somehow before reading?). Maybe the refractometer is actually more accurate at these early stages when readings are difficult with the hydrometer??

Miker

Snip

No, I don't.

It could be that the server he's using is black listed for some reason.

Andy