Editing Malolactic fermentation (section)

==Measuring malic content==
[[File:MLF spotting sheet with acids noted.png|right|thumb|A paper chromatography sheet showing that one wine still has some level of malic present while the other three wines have seemingly gone through malolactic fermentation]]
Winemakers can track the progression of malolactic fermentation by [[paper chromatography]] or with a [[spectrophotometer]]. The paper chromatography method involves using capillary tubes to add small samples of the wine to chromatograph paper. The paper is then rolled and placed in a jar filled with a [[butanol]] solution containing [[bromocresol green]] indicator dye for several hours. After the paper is pulled out and dried, the distance of yellow-colored "splotches" from the base line denotes the presence of various acids, with tartaric being closest to the baseline followed by citric, malic, and finally lactic acids near the top of the paper.<ref name="Yair"/>

A significant limitation to paper chromatography is that it will not show exactly how much malic is still remaining in the wine, with the size of the "splotch" on the paper having no correlation to a quantitative figure. The sensitivity of the paper is also limited to a detection threshold of 100–200&nbsp;mg/L while most measurements of "MLF stability" target a malic level of less than 0.03 g/L (30&nbsp;mg/L).<ref name="Zoecklein"/>

The enzymatic method allows for a quantitative measurement of both malic and lactic acids, but requires the expense of reagent kits and a spectrophotometer that can measure [[absorbance]] values at 334, 340, or 365 [[nanometre|nm]].<ref name="Zoecklein"/>