Vitamin C and mortars

[Canuck]

I don't have a problem with crushing vit-c tablets. I buy the Costco branded non-chewable ones and they dissolve in a couple of minutes. I then use a steel coffee filter to get rid of much of the inert binder. Cheers

 

[derevaun]

I read somewhere that stone mortar and pestles can retain residues. I figure it's enough to be significant but not enough to matter The tricky part is getting all the visible powder off with the sometimes small amount of water needed for a given formula. Probably a ceramic m&p would help in both regards?

I found sodium ascorbate powder in a supplements store. Folks who work there are generally good at fielding questions.

 

[Gerald Koch]

Unless one is getting a really good price for the tablets then it's probably cheaper to buy ascorbic acid crystals.

Tablets can also contain a mixture of sodium ascorbate and ascorbic acid. The reason for this is the acidity of the acid itself which can cause stomach upset in high doses. This makes their composition unpredicatable for developer use.

 

[Donald Qualls]

If you buy supplement grade ascorbic acid, the exact content will be on the label. I bought 97% ascorbic acid from GNC (and probably overpaid, at about $14/lb); I got powder form, verification on the label (FDA enforced) that I was getting only ascorbic acid and not an ascorbate ester, and the end result dissolves 100%.

 

[Gerald Koch]

I buy sodium erythorbate from Sutton's Bay Trading Company for $6.33 per lb. This avoids having to neutralize ascorbic acid and makes things a bit easier.

 

[gainer]

Unless you're dissolving it in glycol.

 

[srs5694]

I buy sodium erythorbate from Sutton's Bay Trading Company for $6.33 per lb. This avoids having to neutralize ascorbic acid and makes things a bit easier.

That depends on the formulas you're following. Lots of them, including most of Pat Gainer's and Ryuji Suzuki's, call for ascorbic acid, not sodium ascorbate.

FWIW, the only time I've done so to date, I bought a pound of technical-grade ascorbic acid from The Chemistry Store. It was $10.89 for a pound at the time, but they seem to have changed their packaging so that the minimum order is now $22.18 for 2 pounds. It's worked fine in everything I've made from it -- at least, the developers develop the film or paper in reasonable time.

 

[Gerald Koch]

I make an Xtol type developer for fast films. It is easier to use the sodium salt rather than neutralize ascorbic acid even if the original formula calls for ascorbic acid. The calculation is rather trivial.

 

[pnance]

If you're still looking for a mortar and pestle, try Mountain Home Biological, they have them in glass (no pores, easy to clean), the small one (60ml) is less than $4, a larger one (180ml) is less than $6

 

[dancqu]

I'm quite sure you're local Home Brew Wine and Beer
supplier will have A. acid as well as one or two other
darkroom chemicals. Dan

 

[Donald Qualls]

I'm quite sure you're local Home Brew Wine and Beer
supplier will have A. acid as well as one or two other
darkroom chemicals. Dan

My local brewing supply house had citric acid and tartaric acid (for alt process), but didn't have ascorbic or erythorbic acid -- they have little if any use in brewing or winemaking, where sulfites (including bisulfites and metabisulfites) are used as yeast-friendly preservatives with a much better solution life than ascorbate or erythorbate.

 

[Ryuji]

Ascorbic acid is very yeast friendly. By lowering the reduction potential, ascorbic acid stimulates the growth of yeast. Ascorbic acid and erythorbic acid are used frequently in yeast fermentation, such as baking yeast breads. I don't know of any use in brewing. It was once used in wine making, but it seems less common nowadays.