Potassium at Pressing?

That's too much for a red wine. At pressing if you're doing MLF, it's probably not finished, so adding SO2 would be detrimental. If you rack carefully, you'd need only about 10-20ppm added.

B) is the way to go - depending on your pH, you might not go to 50ppm,

Pp

As I understand it, what we're after is free molecular SO2. How much free SO2 is generated by any given quantity of KMS (short hand for potassium metabisulfite) is inversely influenced by pH. Meaning; the more acidic the must or wine, the greater the free molecular SO2 generated. I use a simple chart to help me determine the desired level of SO2 to add at crush time. One chart for red wine, one for white. A good source for info by which to determine these ratios is Margalit's book.

After crush, I test for free SO2 (recently switched from Ripper to aeration-oxidation; life is MUCH better!) to determine if I need to add more. Usually at racking time. Again, I try to keep the freee SO2 within a range determined by the pH. Before bottling, I try to get free SO2 to 30 ppm.

Personally, I try to minimize the addition of KMS. By testing more frequently, and only adding as necessary, I hope to keep sulfite additions to the minimal necessary to protect the wine. I'm one of those 'sensitive nose' types who can detect when there is too much sulfite in a wine.

A more or less standard SO2 regime for a wine intended to go through MLF would be.... Little or no SO2 at crush (more than 30 PPM will retard MLF) No further SO2 additions until the wine has finished MLF. Then add about 50 PPM of SO2 as soon as the wine has finished MLF. Roughly half of the added 50 PPM will be quickly bound up and about half will remain as free SO2. After a week or two, measure the free SO2 and the pH of the wine. Calculate the amount of free SO2 is needed to produce 0.8 PPM of molecular SO2 and make the appropriate addition.. Maintain 0.8 PPM of molecular SO2 until the wine is bottled.

I would not buy an SO2 test kit. I would read a book and then buy the necessary items separately. You will need to practice measuring SO2 in red wines to become proficient.

Good luck.

Good information from everyone. THanks. But shouldn't I be worried about protecting the wine during pressing? Or am I missing something? Also, i was reading another post which said 1 camden tablet is about .44gm KMS. If that is the case, the recommended 1 tab per gal (that is supposed to equal 50ppm) really is only half that. If I put gallons in to milliliters and divide into 1 million parts I get .0038, which is one millionth of a gallon. Now 50 of those parts is .19 mls or .19gm and not .44gm. Thoughts?

Ric wrote:

Ric, What are the Ripper and aeration-oxidation tests? I use the Titrets to measure SO2.

Ric wrote:

Lum - do you think .8 ppm molecular SO2 is necessarily required? Some literature suggests a range between .5 and .8; I've been tending towards the lower end of that range in a desire to use as little KMS as possible. Could be dumb luck, but thus far (only two seasons at those lower levels, admittedly) no issues.

thoughts?

I think some terminology may be confusing me. why are we at .8ppm when up til now we've been adding kms in the range of 50ppm?

Ric wrote:

KMS is added, depending on pH and winemaking tactic, in amounts ranging from

I think a lot of guys on here are confused on here because this group is becoming a lot like chemistry class. Certain people are on here just to ensure they don't F*** ** a batch of wine on a very basic level. Many simply do not have the tools required to measure sulphite levels, check for completion of MLF, etc. Many of you are miles ahead of the rest of us. It's usually obvious by the initial question,at what stage the poster is at. Sometimes the answers,although top knotch in my opinion,are just basically useless to some of us at times. Trying to say this as diplomatically as possible. I'm sure it has been addressed before.

I think a lot of guys on here are confused on here because this group is becoming a lot like chemistry class. Certain people are on here just to ensure they don't F*** ** a batch of wine on a very basic level. Many simply do not have the tools required to measure sulphite levels, check for completion of MLF, etc. Many of you are miles ahead of the rest of us. It's usually obvious by the initial question,at what stage the poster is at. Sometimes the answers,although top knotch in my opinion,are just basically useless to some of us at times. Trying to say this as diplomatically as possible. I'm sure it has been addressed before.

Yes. I agree. (on here, on here) But I figure if I hang in there and read, I will learn more about chemistry and what to do than just reading books. My fruit and grape wines are better from reading strange, over my head discussions that I finally got a piece of. smile.

Your comment is good, hopefully some will remember some of us are just in this hobby a few years and not high volume (I make 120 bottles a year). However, I enjoy all the postings as long as it stays away from nasty or rude comments, or insulting. I mean, is there really a stupid question? smile. Is there really snobs among us? I don't think so.

DAve

snipped-for-privacy@gmail.com wrote:

Ric, I don't think 0.8 PPM is a magic number. Down here in the southwest, pH levels tend to be high so many winemakers try and maintain 0.8 PPM for white wines and 0.5 PPM for red wines. After all, it is possible to make good wine without using any SO2. But, the wine wont last very long and the winemaker had better keep things very clean. Lum Del Mar, California, USA

Andy, You make a good point. I wrestled with this issue for some time. I finally decided education is more important than saving a small batch of wine. But, I may be WRONG. What do you think is the best way to address this issue? Lum Del Mar, California, USA

RE....

Actually Lum , I am with you all the way. I am trying thru this group to educate myself.I think the key is to just recognise whether the poster is a new poster, inexperienced at the craft,etc. and try to address the question from there. The guys on here like yourself all give exceptional advice which would cost us newer folk hundreds or thousands of dollars to learn elsewhere. There are times though when a small batch of wine to some guys is a very big thing because we fuss over it so very much. It's such a source of pride and joy to us.

Apologies if the posts weren't on point. And you make a very good point - to try to match the technicality of the answer to the demand of the question. Many a time I have been lost by the technicality of others' writings - so I'm sympathetic to the point.

The problem is that sometimes simplifying can be misleading - and I'd hate to cause someone mess up their batch of wine. An analogy; if someone asks you "how do I get get this car going?", and you tell them how to push the gas pedal, you've answered the question. But if they don;t understand gears, or brakes, etc - well, they might not exactly be prepared to drive the car, eh?

To attempt a better answer to the question - I recommend reading Lum's online book (excellent) or, if you are more inclined to play with the science, get a copy of Margalit's book.

Point well made Andy. I will try and keep it in mind. Lum Del Mar, California, USA

Going with the Keep it Simple process, what about this for and approach for those without a chemistry background or a lot of hardware who want to use titrettes?

• Subtract that value from any subsequent reading and maintain sulfite levels based on this extrapolated value.

Example: Post fermentation reading = 22 PPM. Wine is racked and 50 PPM is added The next rack 42 PPM is measured.

I'm not saying it's a precise process but I do think either Lum or Ben Rotter proposed that a while back and it's intriguing.

As to the 0.8 molecular; it's a more precise way to discuss sulfite levels in wine. The general value of 50 PPM is based on maintaining

I can post a chart of pH vs recommended PPM sulfite from Margalit but I think it's already in the FAQ.

Joe

Lum Eisenman wrote:

Interesting suggestion. I'll need to go back through my recent past winemaking notes to determine if the primary assumption (that "all of the free SO2 has blown off in fermentation") holds true in my own experience. To my recollection there is usually some significant free SO2 remaining after primary. Maybe not enough to invalidate your suggested recipe approach though.

The problem, of course, with all these 'recipe' approaches is that the underlying premise is that all wines are more or less equal and that all winemaking situations more or less the same. I don't find that to be true. To my mind the only way to control the winemaking process is to have reasonably empirical information on which to base winemaking decisions. Biggest improvement in my own winemaking life was this year when I moved from Ripper to A-O for SO2 measurement. Once you get the hang of it, the A-O methodology is pretty straightforward (certainly easier than Ripper) and fun.

I guess for those making small lots on an infrequent basis the investment of $ and time is not worth it and a more programmatic approach is the easiest and most efficient. But if the goal is to make 'quality' wine on a consistent basis then knowing SO2 levels and making informed decisions is critical, MHO.

As the original poster of the question, I should say that I appreciate the technicallity of the answers simply because they are more 'precise' answers than simplistic ones. Both would leave me with more questions, but the technical replies direct me to what the next question is, rather than a vague and simplistic reply which would leave me scratching my head and not knowing what next to ask. I get Andy's point, however, and perhaps it is up to the poster to say, "I don't get it, please simplify". Further to that point, I am thankful for everyones help in not f'ing up my 90 gal batch.

snipped-for-privacy@gmail.com wrote: