......
But personally I'd be looking to reduce lactose not increase it, I find there are few beers that are improved by lactose but it gets used as some kind of universal band-aid for poor brewing.
Strikes me that all of your problems could be fixed by having less optimal conditions for the Philly Sour, so that it attenuates less (sweeter, more body) and produces less acid. So I'd be looking at doing a starter, which would strip out sterols, and increase your cell count both of which will be less optimal for the yeast. And don't oxygenate the wort.
Forgot to mention in post, that I didn't fancy even the suggested 400g of lactose. So tried post ferment additions, starting from 200g, but that was way too tart.
Struggled, at the time, to find alternative tested recipes, for a Philly fruit sour. And ClownPrince's looked fine as a starting point for experimenting.
I'll happily add lactose, rather than throw a test batch away.
Since came across
Raspberry sour recipe with higher grain proportion. But it notes that, more body and sweetness would help, and suggests lactose!
Info from
lallemandbrewing/ Philly sour webinar
Majority of lactic acid is produced over the first 5 days.
Brewhouse turns, work fine and don’t affect final PH. Provided that second turn is added while yeast is in the acid producing phase (within 24 hours to be certain).
So delaying, in starter by a day or two, mightn’t help.
Overpitching can reduce final acidity. But for their highest pitch rate example, they say
“this might” reduce acidity by 24%
.
Underpitching, at 0.1 g/l, can give a 58%
reduction.
But you'd definately need a second yeast, from day 4, for ethanol production.
lallemandbrewing/philly-sour-faq-2
Higher levels of glucose in the wort, either from lower mash temperatures or glucose added as an adjunct, will increase lactic acid levels.
Co-pitching with small amounts of another brewing strain will reduce the amount of lactic acid produced due to competition for sugars (in the lab, 10% Nottingham cut the lactic acid level by about 50%)
But the webinar, says “don’t co-pitch”.
“Philly Sour should NOT be used as the fermenting strain during bottle conditioning”. They don’t explain why, but it could be it’s not reliable, because it’s high flocculation might leave little in suspension. This is given as
the likely reason for stuck fermentations, at lower temperatures.
I'd not noticed that warning. So bottle conditioned as normal (no added yeast), but with no problems. Maybe botteling at day 9, or raising some yeast sediment before priming, helped.
Couldn’t see any mention, of sterols (nutrients) affecting lactic acid production. Have you seen this in relation to Philly Sour?
Also not clear how having a starter, would affect wort nutrient levels. Or is idea to stress the yeast while in the starter?
Next time, after a higher temperature mash, I'd make any glucose addition on day 5. So it produces mostly ethanol (along with any sweet fruits). But I suspect my blackcurrants contain fairly little sugar, so are probably still fine, going in at start.
A partial mash, with DME addition on day 5, could be another fix.