# Last edited on 2017-02-08 04:37:17 by jstolfi EXTRACTING TARTARATE SALTS FROM GRAPE JUICE TARTAR Solubility of KHTar in H2O (g in 100 ml): 20 C 0.37 100 c 6.10 KHTar is insoluble in ethanol. CaTar is nearly insoluble in water even at boiling. ---------------------------------------------------------------------- 2016-12-18 Placed the dirty raw tartar (dark purple) in ~175 ml H2O. Heated. Tartar did not dissolve completely at 80 C. Filtered when started to boil. (Thermometer showed 95 C). Repeated 3 times: { Drained all but ~50 ml of uberliq (T0) to filter, added ~50 ml H2O, boiled again. } The dark purple residue (Tr) seems insoluble even in boiling water. Drained remaining uberliq (T0) and solids to filter. Filtrate is (T2). The ppt (T3) still had some crystals presumed to be KhTar. The moist ppt (T3) (~10 g) was boiled with 40 ml of H2O. Drained to same filter paper. Filtrate merged into (T2), ppt on filter (T3b). Added 30 ml of H20 to (T3b)+(Tr); boiled and filtered again through same paper. Filtrate merged into (T2). Residue on filter is (T3c). Crystallization Cooled (T2) to ~2 C in an ice bath. Deposited a ppt (T8) crystalline, dirty with purplish stuff. Decanted the uberliq (T6), which was ~250 ml, purple-brown, cloudy at 8 C. Washed the ppt (T8) twice with 2-3 ml of ice water. Filtered the (T6) uberliq and the washed (T8) with 28µm paper at ~12 C. Filtrate (T9) was ~300 ml, clear, dark wine-colored. The ppt on filter was washed with a few ml of ice water, then three times with ~6 ml of ethanol 92%. The residue (T8) on filter was ~7 g. Should require ~120 ml of water at 100 C, ~130 ml at 90 C. Placed (T8) and its chopped filter paper in a beaker with 130 ml H2O. Dissolved completely to a clear light red liquid (T10). The moist filter paper still weights ~3 g, so it must have contained some KHTar before. Treatment of initial residue with NaHCO3 Added 50 ml H2O to (T3c) (including torn filter paper). Added NaHCO3 in small amounts until bubbling stopped. Result was a very dark (nearly black) suspension (T4). Filtered through 20µm paper. Filtrate (T5) clear, light grayish brown. Residue on filter included some hard round pebbles. Added ~20 ml H2O, boiled, dumped through same filter. Residue (T6) left on filter was nearly black, no longer mixed with crystals as previously. Put (T6) in a beaker with 25 ml of H2O and boiled again. Added more NaHCO3 until bubbling really stopped. Filtered with 28µm paper, merged filtrate with (T5) even though it had different color (dark brown). Re-filtered (T5) through W201 (7--14 µm pores). Filtrate was clear brown (~40 ml). Practically no ppt retained on filter. ---------------------------------------------------------------------- 2016-12-19 Chilled (10) at ~9 C. Filtered with 28µm paper. The ppt (T12), ~6 g moist, was crystalline with some purplish impurities. Washed with ethanol 99% and ice water. The filtrate (T11), ~125 ml, was clear and light red. Separation of tartrate as calcium salt The filtrate (T9) from the first KHTar extraction, which was filtered at ~20 C, should contain ~1.1 g of KHTar. Added 5 ml of CaCl2 solution in an attempt to precipitate the tartrate as CaTar. ---------------------------------------------------------------------- 2016-12-23 Weigthed (T2) which was now dry: 5 g, plus maybe 0.5 g absorbed in filter paper and adhering to beaker. Added 85 ml of water which should be just enough to dissolve all at 100 C. Boiled to dissolution at ~95 C, yielding solution (T13). Meanwhile the filttrate (T9) from the first extraction developed a colony of mold on the surface: ~10 mm diam, greenish gray inside, with a white border ~2 mm all around. By mistake, spilled ~40 ml of the (T13) solution at ~60 C. Boiled the remaining (T13) and tried to coll slowly by wrapping the beaker in paper towel and covering with majipak. Deposited crystals, but they are still dirty with purplish-brow-red, only a tiny bit lighter. What is going on? ---------------------------------------------------------------------- 2016-12-25 Filtrate (T9) developed mold colonies on surface: 4 colonies black with grey halos, about 3 cm diam; 2 colonies light greenish gray, about 1 cm and 3 cm diam; 1 colony darker greenish gray, ~3mm diam. Filtrate (T11) too developed mold floating on the surface, and a fluffy ppt at bottom. The liquid (T13) had filamentous fluff, possibly mold, over the bottom crystalline ppt. Stirred vigorously and decanted the milky brown uberliq (T14) with some of the fine dust over the ppt. Washed the ppt (T13) with a bit of water. Still some fluff remained attached to it. It may be nucleating the crystals, which would explain why it can't be separated. ---------------------------------------------------------------------- 2016-12-27 There is definitely a mold or bacterial growth on the cold tartar uberliqs (T11) and (T13). Merged them in a single beaker (T15). ---------------------------------------------------------------------- 2017-01-15 The (T16) liquid had a thin layer of crystals at bottom. It also developed a mold colony floating on the surface. The aerial part was a grey dimple albout 1 mm wide and 1.5 mm tall. The submerged part was a fuffy lilac half-ball maybe 7 mm in diameter, with a 1-2 mm almost clear colorless layer all around. ---------------------------------------------------------------------- 2017-01-03 Discarded (T15) and the uberliq of (T9). A crystalline reddish-white ppt was left in (T9); presumably CaTar. Boiled that ppt in 100 ml of water (T9a). The ppt of (T9a) did not dissolve much. Decanted 75 ml of clear uberliq (T16) at 70 C. Lef the ppt in the beaker (T17). The uberliq (T16), cooled in in an ice bath, deposited only a few tiny crystals at the bottom, not even a complete layer. So (T17) must be CaTar. Another batch Got another batch of crude tartar from grape juice (~1 g). Ground it. Added ~40 ml water, boiled. Filtered with 7 um paper at 80 C. Filtrate (T19) was clear medium red. On cooling, crystals started to form at ~40 C. Spilled it all, darn! ---------------------------------------------------------------------- 2017-01-25 Tue Another batch Got some more tartar from grape juice. Washed it with water and a bit of ethanol 46%. Filtered through paper towel. The washed tartar (Tb2) was dark wine brown. Wash water (Tb1), ~170 ml, was brownish wine red, very cloudy. Heated to ~93 C. Let it cool slowly in an erlen with paper towel jacket, on the turned-off stove. Then cooled to ~10 C. It became whitish brown. Filtered (Tb1) at ~10 C on 14 um paper. The filtrate (Tb3) was still nearly opaque whitish brown. The ppt (Tb4) was almost null. ---------------------------------------------------------------------- 2017-01-27 Thu Discarded the ppt (Tb4) of the filtering of (Tb1). Discarded (T16) from earlier run. Added ~75 ml water to the washed tartar (Tb2). Heated to ~92 C. Allowed to cool slowly with paper jacket. Decanted the uberliq of (Tb2) at ~25 C (still brown opaque). Merged with into the filtrate (Tb3) of (Tb1). Added again ~75 ml water to the undissolved solids of (Tb2) yielding (Tb2a). Heated to boiling, which strangely was 96 C not 100 C. Maybe KHTar decomposes releasing CO2? After a few minutes of boiling (Tb2a), the solids desintegrated and the liquid became lighter and cloudier. Filtered (Tb2a) through 3 ply of paper napkin at ~90 C. The filtrate (Tb5) is almost clear, light brownish red (even at 60 C). The ppt (Tb6) was just some fluffs. Washed it with ~15 ml of water at ~90 C and discarded it. Left the filtrate (Tb5) to cool with paper towel jacket, then in ice water bath. Filtered (Tb5) at ~10 C with 28 um paper. The filtrate (Tb7) was somewhat mikyl reddish brown. The ppt (Tb8) was crystalline reddish-brownish white. ---------------------------------------------------------------------- 2017-02-05 Sat Liquid (T5) had mold growing on its surface. Two colonies, each with a rounded conical green-gray dimple at the center, ~2mm diam, ~1 mm tall; a raised conical shirt around it, ~1.5 mm wide; a flat fluffy layer with roughly round shape, ~20 mm diam; and a halo of sparse white "dust grains", ~3 mm wide. Liquid (Tb3) too had several colonies: One colony with a green-gray raised center, 3--4 mm diam and ~1 mm tall, with a dimple in the center; then a gap 0.5 mm wide all around; then a gray irregular grainy ring, slightly raised. Two colonies, each with a thin fluffy halo ~40 mm diam; and a thicker tan layer in the center, ~12 mm diam. Other colonies, less distinctive. Discarded (T5), (Tb3), (Tb7). ---------------------------------------------------------------------- 2017-02-07 Tue New batch Collected the wet solid residue from another 1 liter bottle of grape juice, including ~35 ml of dense mix of juice and fine ppt. Boiled the mixture (Tc0) of juice and solids. Thermometer reads 95 C (?!). Color changed from opaque dark purple to opaque reddish brown. Stopped boiling when it was reduced to ~25 ml. Some of the fine suspended solids coalesced into larger brown-black dust particles. Added water to 100 ml. Heated tó > 90 C again. Filtered hot 90--60 C through paper napkin Snob folded in 4. Filtrate (Tc1) is almost clear light red. The ppt (Tc2) left on the filter is a purple brown paste with some purple black 'pebbles'. Repeated twice: { Crushed the 'pebbles', boiled them in ~20 ml water, filtered as above. Filtrate added to (Tc1). } Squeezed the filter with fingers to get last drops of filtrate. The residue on the filter (brown purple black) was very small; discarded. The filtrate (Tc2) became a bit cloudy. Heated again (Tc2) in wide mouth erlen with alum foil jacket, to concentrate by boiling. Thermometer showed 104 C (?!). Boiled down to small volume. Filtered at 80--70 C with 28 um paper. Washed filter with a few ml of boiling water, twice. The filtrate (Tc3), 20 ml, is again purple brown opaque. Residue on filter was very small, discarded. The filtrate (Tc3) deposits crystals on cooling. Cooled in ice bath. Added 10 ml of ice water to facilitate pouring. Filtered at ~4 C. Washed beaker and ppt on filter with ~15 ml of ice water. Squeezed filter paper with fingers. The filtrate (Tc4), ~35 ml, is opaque purplish brown. The ppt (Tc5) is crystalline brownish, weights ~1 g when almost dry. Put the ppt (Tc5) in a beaker with 50 ml water and the paper of the filtration. Boiled the mix (Tc6); the ppt dissolved completely. Filtered and washed at 80--70 C with W201 paper. The filtrate (Tc7), ~33 ml, is clear orange. Residue on filter was very small, discarded. Cooled (Tc7). Started to crystallize at ~39 C. Cooled in ice bath to ~8 C. Filtered (Tc7) at ~10 C with 14 um paper. Filtrate (Tc8) is clear slightly pink. Ppt (Tc9) is brownish pink; not much different from (Tc5). Maybe should try to use active carbon to clear the red pigment...