Pipette precisely 10 ml of filtered

Pipette precisely 10 ml of filtered sample to a 25 ml volumetric flask and top-off with distilled water. 3. Pipette 10 ml of the diluted/filtered sample to a small beaker, insert a magnetic stir bar and pH probe. Add enough distilled water to ensure that the pH probe is sufficiently submerged. 4. Excessive levels of SO2 (previously added to the juice/must) can introduce error into the YAN determination. If SO2 > 150 PPM, add 1 ml of 3% hydrogen peroxide to neutralize the SO2. 5. Turn on the magnetic stirrer and titrate the sample with 0.05 N NaOH until neutralized (pH=8.0). 6. Add 2 ml (nominal) of previously neutralized formaldehyde solution to the sample using a small graduated cylinder. The formaldehyde will react with the YAN sources yielding a proportionate release of H+ ions (thus, lowering pH). 7. Record the current level of 0.05 N NaOH in your burette. 8. Titrate the sample with 0.05 N NaOH until pH = 8.0 to neutralize the H+ ions released in Step 6. 9. Record the new level of 0.05 N NaOH in your burette and calculate the amount needed to neutralize the sample following the addition of the formaldehyde solution. 10. Estimate yeast assimilable nitrogen (YAN) level as follows:

Pipette precisely 10 ml of filtered sample to a 25 ml volumetric flask and top-off with distilled water. 3. Pipette 10 ml of the diluted / filtered sample to a small beaker, insert a magnetic stir bar and pH probe. Add enough distilled water to ensure that the pH probe is sufficiently submerged. 4. Excessive levels of SO2 (previously added to the juice / must) can introduce error into the YAN determination. If SO2> 150 PPM, add 1 ml of 3% hydrogen peroxide to neutralize the SO2. 5. Turn on the magnetic stirrer and titrate the sample with 0.05 N NaOH until neutralized (pH = 8.0). 6. Add 2 ml (nominal) of previously neutralized formaldehyde solution to the sample using a small graduated cylinder. The formaldehyde will react with the YAN sources yielding a proportionate release of H + ions (thus, lowering pH). 7. Record the current level of 0.05 N NaOH in your burette. 8. Titrate the sample with 0.05 N NaOH until pH = 8.0 to neutralize the H + ions released in Step 6. 9. Record the new level of 0.05 N NaOH in your burette and calculate the amount needed to neutralize the sample following the addition of the. formaldehyde solution. 10. Estimate yeast assimilable nitrogen (YAN) level as follows:.

Pipette precisely 10 ml of filtered sample to a 25 ml volumetric flask and top-off with distilled water. 3. Pipette 10 ml. Of the diluted / filtered sample to a small beaker insert a, magnetic stir bar and pH probe. Add enough distilled water to. Ensure that the pH probe is sufficiently submerged. 4.Excessive levels of SO2 (previously added to the juice / must) can introduce error into the YAN determination. If SO2 > 150, PPM. Add 1 ml of 3% hydrogen peroxide to neutralize the SO2. 5. Turn on the magnetic stirrer and titrate the sample with 0.05 N. NaOH until neutralized (pH = 8.0). 6.Add 2 ml (nominal) of previously neutralized formaldehyde solution to the sample using a small graduated cylinder. The. Formaldehyde will react with the YAN sources yielding a proportionate release of H ions (thus lowering, pH). 7. Record. The current level of 0.05 N NaOH in your burette. 8. Titrate the sample with 0.05 N NaOH until pH = 8.0 to neutralize the. H ions released in Step 6. 9.Record the new level of 0.05 N NaOH in your burette and calculate the amount needed to neutralize the sample following. The addition of the formaldehyde solution. 10. Estimate yeast assimilable nitrogen (YAN) level as follows: