Hi, I have a beginner's question about why a demijohn full of pressed organic apple juice will not start fermenting. Other brews from (nearly) the same batch are doing fine. I've consulted threads on the subject, and none of the recommended remedies seems to work. As a beginner, I expected getting a decent result would be a challenge, but I never imagined getting fermentation to start would be difficult.
Some background... I was unexpectedly offered a large quantity of apples (eaters, variety unknown), which I had pressed (thank you, Chiltern Ridge!). [This is my official excuse for not doing much pre-planning]. I filled a 24-litre (~5 gallon) bin and two 4.5-litre (~1 gallon) glass demijohns. I added sodium metabisulphite & waited 24 hours, then added dextrose, pectalose and yeast, and fitted airlocks. The bin and one demijohn started fermenting, but the other demijohn didn't. After 2 weeks it barely has a bubble on the surface.
The awkward brew is slightly different to the others, in that it contains 1 litre of organic crabapple juice (strained after boiling, not pressed) and the others don't. Otherwise it os being kept in the same conditions as the successful brews. Thinking I may have overdosed with Na2S2O5 and/or sugar (although the other vessels are doing fine) and/or crabapple juice, I diluted it 50/50 with shop-bought apple juice. I ended up with *two* inactive demijohns (SG 1.075).
I tried adding two more doses of cider yeast (one old & generic, one new & by Youngs), but after a day of very weak activity, bubbles stopped forming. I tried warming them (they were previously at 20oC), but bubbling didn't picked up. I have ordered a pH-test-kit, but the juice does not taste acidic (it still smells and tastes like apple juice) so I'm not sure that is the problem. I even tried replacing the airlocks with fine cloth, after reading that some primaries need access to air (oxygen, maybe?). None of these efforts have had any effect.
I am going to do the following, based on tips found by reading similar threads...
1. Shake to aerate, then replace the airlocks
2. Add yet more Youngs cider yeast (I assume the previous doses have died by now), which I will start outside the demijohns, and add only after I've verified its vigour
3. Add yeast nutrient
4. Maybe add tannin (1 tea bag stewed 1/2 hour in a half-pint mug, divided between both demijohns)
5. Check pH when kit arrives, and adjust accordingly
Is it worth dosing the reluctant brews with juice from the demijohn that *is* bubbling nicely? Is there anything I might have done wrong when preparing the crabapple juice? And can anyone suggest any other tactics that I may have missed? Thanks for reading, and for any tips you may have.
Some background... I was unexpectedly offered a large quantity of apples (eaters, variety unknown), which I had pressed (thank you, Chiltern Ridge!). [This is my official excuse for not doing much pre-planning]. I filled a 24-litre (~5 gallon) bin and two 4.5-litre (~1 gallon) glass demijohns. I added sodium metabisulphite & waited 24 hours, then added dextrose, pectalose and yeast, and fitted airlocks. The bin and one demijohn started fermenting, but the other demijohn didn't. After 2 weeks it barely has a bubble on the surface.
The awkward brew is slightly different to the others, in that it contains 1 litre of organic crabapple juice (strained after boiling, not pressed) and the others don't. Otherwise it os being kept in the same conditions as the successful brews. Thinking I may have overdosed with Na2S2O5 and/or sugar (although the other vessels are doing fine) and/or crabapple juice, I diluted it 50/50 with shop-bought apple juice. I ended up with *two* inactive demijohns (SG 1.075).
I tried adding two more doses of cider yeast (one old & generic, one new & by Youngs), but after a day of very weak activity, bubbles stopped forming. I tried warming them (they were previously at 20oC), but bubbling didn't picked up. I have ordered a pH-test-kit, but the juice does not taste acidic (it still smells and tastes like apple juice) so I'm not sure that is the problem. I even tried replacing the airlocks with fine cloth, after reading that some primaries need access to air (oxygen, maybe?). None of these efforts have had any effect.
I am going to do the following, based on tips found by reading similar threads...
1. Shake to aerate, then replace the airlocks
2. Add yet more Youngs cider yeast (I assume the previous doses have died by now), which I will start outside the demijohns, and add only after I've verified its vigour
3. Add yeast nutrient
4. Maybe add tannin (1 tea bag stewed 1/2 hour in a half-pint mug, divided between both demijohns)
5. Check pH when kit arrives, and adjust accordingly
Is it worth dosing the reluctant brews with juice from the demijohn that *is* bubbling nicely? Is there anything I might have done wrong when preparing the crabapple juice? And can anyone suggest any other tactics that I may have missed? Thanks for reading, and for any tips you may have.
