Just curious about adding salt ions and scale range. - Page 2

michaeltrego · 01-27-2012, 03:04 AM

I recently bought this one on Amazon: American Weigh Signature Series Black AWS-100 Digital Pocket Scale, 100 by 0.01 G by American Weigh $11.79

Looking forward to using it on my Maibock soon...

**brushvalleybrewer** · 01-27-2012, 10:50 AM

I use a Blade Scale. Resolution of 0.1g. It makes me look like a drug dealer, but it helps me make great beer, so I have learned to deal with it.

**Snafu** · 01-27-2012, 11:00 AM

Quote:

Originally Posted by ajf

I use http://www.americanweigh.com/product_info.php?cPath=24&products_id=290
Works fine, but I have to replace the batteries every year or so.

-a.

I was actually looking at these, does the lid lay flat allowing you to use a tray?

**brushvalleybrewer** · 01-27-2012, 12:12 PM

broadbill · 01-27-2012, 12:17 PM

Quote:

Originally Posted by mabrungard

I find that the ability to measure to 0.1 gram is quite accurate enough when dealing with the typical 5 gallon batch amounts.

bingo....0.1 g accuracy is probably sufficient. Doesn't hurt if you go 0.01 though, I just wouldn't go too far out of my way for it.

DSmith · 01-27-2012, 12:53 PM

Quote:

Originally Posted by Snafu

I was actually looking at these, does the lid lay flat allowing you to use a tray?

The lid doesn't come off. I cut-up a few sheets of paper and store them in the scale lid for measuring on.

http://www.americanweigh.com/product_info.php?cPath=24&products_id=290

This scale is great for treating water and measuring hops. It's less than $12 on Amazon. It has a "floating zero" so if you start out with the scale tared to 0 you need to put at least 0.03 gm on the scale to prevent it from self-adjusting back to 0. I generally put a piece of paper and not tare the scale, then start weighing.

A campton tablet weights about 0.65 gm and treats 20 gallons. I dillute my tap water with >75% RO/distilled water and commonly measure <0.1 gm of a crushed tablet to treat the tap water for chlorine. I also dechlorinate my cleaning and sanitizing solutions at the same to make the best use of a single tablet.

**Snafu** · 01-27-2012, 03:03 PM

I went with this http://www.amazon.com/American-Weigh-Digital-Pocket-Scale/dp/B003STEIYY also got 2 100g calibration weights. I won't have it for this weekends brew, but should be here next week for my next brew. I'll just wing it this weekend. Always done that in the past anyway.

adamreef · 01-27-2012, 05:09 PM

Sorry Sgafu, I am a little late. Maybe could have saved you some $$. Anyway, for anyone looking at this in the future, a very good solution to this problem is to make stock solutions.

Depending on the salt, you can dissolve (pulled out of the air for the sake of an example) 100 grams of a particular salt in a 1L bottle of water. This will give you .1g/ml. It is quite easy to measure 1/10 ml with a small syringe, allowing you to accurately add the salt in .01g increments. 100 grams is about 3.6 ounces which is solidly in the comfort range of whatever scale most of us use for hops.

There are some limitations to this. For example, CaCO3 is very poorly soluble so it is hard to make a solution concentrated enough to be practical. Also, MgCl2 and MgSO4 are both highly hygroscopic (attract water), so when you may be weighing a significant amount of water when you weigh them.

Hmm... maybe this would make a good article to post. May have to work on that.

Hope this helps.

Adam

**ajdelange** · 01-28-2012, 04:37 PM

Quote:

Originally Posted by adamreef

Anyway, for anyone looking at this in the future, a very good solution to this problem is to make stock solutions.

I agree. See #4.

Quote:

Originally Posted by adamreef

For example, CaCO3 is very poorly soluble so it is hard to make a solution concentrated enough to be practical.

Not a problem. Make a suspension. Just be sure to vigorously shake it up just before you pour off the liquid you are going to add. You should seldom need calcium carbonate.

Quote:

Originally Posted by adamreef

Also, MgCl2 and MgSO4 are both highly hygroscopic (attract water), so when you may be weighing a significant amount of water when you weigh them.

Calcium chloride, yes. It will, in any of its forms, continue to attract water from the air to the point where the originally solid salt turns to soup. Most people obtain MgSO4 as the heptahydrate which is pretty stable.

In any case, this is a potential problem regardless of the accuracy of your scales. There are ways around it which are standard laboratory practice (heat in an over at 103 °C for a few hours, cool in a dessicator) but given the level of accuracy required in home brewing it is not necessary to go through this unless you are doing analysis.

**Snafu** · 02-01-2012, 05:18 PM

FWIW, got new scale in today. Seems to be working just fine. Reads in g's the auto off isn't fast at all. Good for slow pokes like me. And as long as I don't breath on it, it doesn't wander around at all. Seems balls on when reading the calibration weights I ordered.