Testing Wine

I'm upping my testing game. I'll soon be in position to do these things like a pro.

I now have a pH meter instead of testing strips.

I ordered a total acid test kit...be here on Thursday

I've always had a hydrometer.

The last thing I need is a way to monitor MLF. How can I do that?

If the pH is where I want it but the acid is not, what does one do? What if the acid is proper and the pH is not?

 

Paper chromatography is what I use. It's a qualitative test that requires you to judge color and spots. It's fairly accurate, cheap and sufficient for me. Quantifiable enzymatic tests are performed by labs and larger wineries with expensive equipment. I cant speak to it, but Vinmetrica offers a ML tester now. They have been great for smaller wineries and home winemakers producing electronic testers that measure SO2 (and others) for about 80% less than Hanna or the other lab grade suppliers. It's my favorite piece of kit and has help me avoid oxidized wines. I now test more often and keep the SO2 at a level sufficient to protect my wine. I would trust their ML meter, but I feel no need to purchase as chromatography gives me all I need to know. Is it finished and can I add SO2? I have not seen them in a while but a company called Accuvin? used to make a test that is an option.

As to pH and TA, read up on the two. There are a number of good articles online. Divergent readings are possible but not typical. Pre-ferment I focus on pH and leave TA alone until after fermentation is complete. Resist the temptation to fine tune your wine too closely preferment and, if you do, make small incremental additions and test in between. The ph scale is logarithmic and despite all the rules of thumb about how x grams of tartaric will change pH, they are just guesses (maybe educated ). Even adding acid using the linear total acidity scale I suggest being careful and incremental. Over shooting acidity is one of the biggest requests for help online. You can add more but removing is difficult.

 

visit morewinemaking.com. scroll down to bottom of page and select manuals. they have red and white winemaking manuals that discus the ph and acids.

 

I just use chromatography as well. I've read it's not 100% accurate when it shows finished though and some wait weeks after it shows complete to sulfite.

Reading up on ph and TA on the forum is going to confuse the heck out of you. Definately 2 schools of thought. Personally I follow whackfol's school of thought but there are others that totally disagree and adjust on TA rather then ph. I shouldn't even have responded to this. I normally just stay out of it.

 

Keep in mind that the easiest way to check Total Acid (TA) is with a pH meter. Sounds crazy but if you will google it you'll see why. You only use on chemical and you read that pH meter looking for the 8.2 reading. Be sure that you understand the different concentrations of NaOH (sodium hydroxide).
It's a lot easier using the pH meter - even a color blind person can do it.

 

pH meter
total acid test kit
hydrometer.
monitor MLF

Vinemetrica for SO2 testing is an expensive, but necessary tool for me, especially since our local grapes tend to have high pH.

 

I spent the money on the accuvin strips MLF, I found that they were expensive 10 strips for $50 and not very accurate. I would recommend chromatography. Would be interested to hear info on the vinmetrica sc-50 mlf tester if anyone has used it.

 

It's a wish list item for me. Maybe a combined family christmas present.

 

Thanks for the information. So if I didn't test before I started the MLF, I'm flying blind? Or can I tell when it's done by doing testing when I think it's finished?

 

The starting point of an MLF is not important. The tests with either the chromo or test strips will tell you when it's done.

 

You can see the mlf activity by the tiny air bubbles on the neck of the carboy. I have some history on when the wine typically ends and I'll tend to piggy back on someone else's test, to assure completion, but it takes 3 months or so for me.

 

Do the bubbles stop rising when complete? Do you rack it before completion...I think it's fine lees on the bottom about 5/16th deep, but I don't know for sure and don't want to leave it sit there on it too long.

 

Do you try to maintain some kind of SO2 during that 3 months?

 

Rack the gross lees on Sunday ran the 1st test for ML to give me a bench mark, I'll test in anothe 2-3 weeks this way I can see the progress. You can see the Malolatic Acid is present very easy to read.

 

I only SO2 after completion of MLF. The bacteria is sensitive to SO2 and would end MLF.

 

Thanks, I don't use it either but my MLF hasen't yet taken 3 months so I was just curious.

 

I find that answers to questions on wine is the same as in poker; it depends.

If the fruit was really good; no mildew, insect, bee, deer damage, with nice clean fruit, I do things differently than if the grapes are in poor shape.

Good grapes, I'll press and let it sit 48 hours, rack, mlf and won't rack again until completion of MLF.

Bad grapes, I'll press and let it sit 24 hours, rack, mlf and then I'll rack again within a few weeks, prior to completion of MLF. Once MLF has been completed, I'll rack again. I do this to keep the wine nice and clean and avoid H2S.

Yes, once ML has completed, the bubble ring around the neck disappear. I wouldn't use it as the measure, only an indicator.

 

I'm careful to sanitize everything, keep containers topped, with breathable bungs. With the generation of CO2 from mlf, I havent had any oxidation/spoilage issues.

 

If you can see bubbles, it is likely ML, assuming AF is complete. If you don't see bubbles, that does not necessarily mean it is complete. As mentioned previously, chromatography is my testing method and I know it to be qualitative and understand its shortcomings. That said, should we care? For me, its completion coincides with when I add SO2. What if I add too early? ML might restart if I don't keep SO2 high enough. That's not bad. If it does, either kill it or let it go. Many people in cooler climates report their wines restarting in the spring as their wine warms up. Waiting too long could risk some oxidation. However, if you practice good sanitation and keep the wine topped up with a minimal headspace and a bubbler, I don't think you would have a problem.

I MLF in my barrels with a little of the fine lees included (see: sur lie). The barrels are probably loaded with bacteria from an earlier wine but i still add a new dose of MLB every year. Because my barrels are 50L, I rehydrate the MLB and divide the liquid between my barrels. I stir the lees every couple of weeks and after I determine (chromatography) that MLF looks complete I switch from breathable bungs to solid. A few weeks later I add SO2. During this time, my barrels are full topped and I am not afraid of spoilage nor oxidization. I have had the bungs blow off a time or two which tells me MLF was not complete and my SO2 had dropped too low to prevent it from restarting.

All in all, my wines turn out very well with few exceptions -- mostly in spite my efforts and not because of them (this is my 19th vintage). Find good grapes, make minimal adjustments, let them ferment and, above all, keep the SO2 level up. It's fun to follow the process and build a knowledge base to react; just don't get caught up in the numbers. Tasting is more fun anyway.

 

Awesome post. Love your winemaking philosophy too. After 19 vintages it sounds like you’ve got a nice comfortable and confident routine.
After a couple years of making both fall and spring grapes I’m finding that 50-55L barrels would ideal sizes for me as well. But barrel suppliers aren’t exactly all over the place. And VA isn’t too far from NJ. Curious- what kinda barrels do you get and where ya gettin them?