Wort is up to temperature and I’m passed the hot-break so time for bittering hops. 15g of Magnum will be boiled for 60mins giving me about 23 IBUs in 21 litres of wort.
Nice work there - That's almost identical to my solution but I made a spiral rather than a ring, and I put 2mm holes instead of needle holes, so that I could re-circulate through it without the holes immediately blocking up with weeny bits of crudSparging now. It’s a kind of fly sparge I guess. I made up a “sparge head” (not a real thing) from the lid of a fermenting bucket, some 3/8 beer pipe, a John Guest “T” piece and a few cable ties. I pierced the ring of beer pipe with a needle to form a spray head. The sparge head is fed from a fish tank pump, a bit more pipe, and another couple of John Guest fittings.
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This is is assembled and working…
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The whirlpool is more about capturing those precursors. The aroma in theory is locked in the precursors which are non-volatile (Thiol is volatile when released during fermentation). The linalool I’m interested in is added in the first dry hop at day zero of fermentation and should be bio-transformed (some at least) into citronellol.Releasing the bound Thiols sounds like an old Dr Who plot line, but this is all very intriguing. I do though think a hop stand over 80 is going to lose a lot of the aroma compounds due to volatility and isomerisation of the alpha acids which apparently is more of a problem for home brewers due to more surface area to volume compared to commercial set ups. However, Scott Janish has a bit in his New IPA book on this. Hop stand at 85 C retained more linalool than at 95 or 75 C. Flavour differences 95 C: citrus, spicy, esters; 85 floral and herby. 75 lowest in categories other than woody. Oxygen added at whirlpool or chilling through aeration releases more of the 'green onion taste thiol' apparently as well.
It does make me wonder whether 90-85 C might be the sweet spot for a hop stand which is higher than I expected, either that or add some at 90 then some at 80 C?
Anna
So that’s the plan. I was going to brew this tomorrow but decided to wait until I receive some yeast nutrient I’ve ordered so it might be a couple of days later. I’ll post the brew-day for anyone with an interest in all this lunacy.
We do but I have some on order so I’m happy to wait a day or two, in part because I also have some Citra pellet hops coming with it. I only have leaf at the moment.
I’ve thought about it. I already account for isomerisation of whirlpool hops. I just need to make an adjustment for the higher temperature. That’s easy enoughReleasing the bound Thiols sounds like an old Dr Who plot line, but this is all very intriguing. I do though think a hop stand over 80 is going to lose a lot of the aroma compounds due to volatility and isomerisation of the alpha acids which apparently is more of a problem for home brewers due to more surface area to volume compared to commercial set ups. However, Scott Janish has a bit in his New IPA book on this. Hop stand at 85 C retained more linalool than at 95 or 75 C. Flavour differences 95 C: citrus, spicy, esters; 85 floral and herby. 75 lowest in categories other than woody. Oxygen added at whirlpool or chilling through aeration releases more of the 'green onion taste thiol' apparently as well.
It does make me wonder whether 90-85 C might be the sweet spot for a hop stand which is higher than I expected, either that or add some at 90 then some at 80 C?
Anna
Let’s see if all this makes any difference whatever. If it does, I’ll tell you what you need to do!My head hurts!
Let’s see if all this makes any difference whatever. If it does, I’ll tell you what you need to do!
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