From Tonys site:
Using a non-sweet aging syrup can mellow out your spirit, without having to store it away for years. Just don't use too much to kill the character of whiskeys.
Try 20g/L of glucose, or 5 mL per litre of glycerine as a starter.
Other little tricks to help round out/mature your whiskey include adding:
a.. a tad of orange flavour [essence], and/or
b.. a bit of sherry (at 1-5% by volume, and Cream Sherry is said to be best), and/or
c.. a bit of port, and/or
d.. a smidgeon of bourbon, and/or
e.. a tiny tiny amount of honey.
Manuka honey at 1 tablespoon per 1125 mL nicely rounds at the Drambuie type flavours.
Soak raisins and/or prunes in some 70% alcohol for a while, then add to brandy.
Try the "liquid smoke" sold by BBQ shops, to enhance that smokey/peaty flavour (just use it very sparingly !)
Hector advises ...
Raisin extract: cover with 90-96% neutral (preferably from molasses or brown sugar) spirit or a week, then strain. I use more of this in rums than in whiskey but it gives both a taste I can just describe like "authentic".
Palisander extract: (deep brown, almost black precious wood, quite similar to ebony -but more expensive- used in making violin "souls", sometimes in guitar's... (How do you call where you mark the chords with your fingers?) The dark wood strips they sometimes use to decorate this and sometimes other parts as well are mad from this wood) cover with 60-70% alcohol from beer, more than a month is better. I think this is the wood that smells more like vanilla I have ever smelled.
Vanillin: It's the artificial thing but it smells and tastes quite different from the real McCoy and gives complexity to the oaky flavour, from powder, with 60-70% neutral spirit.
Neutral spirit composition for blending: don't use just one type of alcohol (grain, sugar or corn). Using a large part of molasses spirit refined to over 90% gives a lot of complexity. It's a waste, though, not to use it for rum! In a blind testing a thorough whiskey drinker friend of mine chose the one blended mostly with molasses spirit over the one with predominantly grain (rice + malts) spirit in the blend (this guy doesn't drink rum, he actually frowns on it).
Water for blending: the guy I mentioned in the other message, the Johnnie Walker ambassador, told us they don't use distilled water for blending but "purified" spring water. Of course I asked what he meant by "purified" but people were getting annoyed by my frequent interruptions and rapid-fire questioning and the guy answered someone else's question instead. Do use distilled water for diluting rum. It's what everybody around here uses.
Thyme: from 90-96% neutral. Cover for a week some fresh garden (I think it's English) variety then strain. I use several drops only in my 6 gal. little barrels but trying in bottle (700 ml) sizes 3 drops aid a lot in complexity.
Strawberry seed extract: from 90-96% from beer or neutral. I made some extract mostly from the seeds that where left after making some strawberry pulp and straining it with a very fine mesh. Several drops of this help enhance and give complexity to the oaky flavour
Honey: here they use a lot of this! As much as half a liter per 50 gal. cask (in top of the line rums) so don't spare it.
Black pepper corns: as in whiskey they a give a bigger "woody" touch and more complexity. Several drops.
Lemmon grass: some fresh leaves in 90-96% from molasses. Not more than a few drops. Gives a nice citric flavour.
Coriander seeds: cover some dried whole corns in 60-70% neutral. Watch out because it has a lot of orange flavour but it gives richness and complexity, a "tropical" like flavour.
And the ones I usually recommend for rum: cinnamon, cloves and nutmeg. Sorry I can't be more specific and exact on quantities but extract making, in my opinion, isn't too precise a process either. It definitively is the way to go, as you told me first and I more than once recommend people who ask about rum flavouring, because it's the only way to aspire to some degree of repeatability.
And the last recommendation for both liquors is to get yourself a nice collection of small oak barrels in which you can forget your rum or whiskey experiments and let age, because there's really no good substitute to the old regular ageing. Thoroughly aerating your recently spiced spirits helps fix the flavour/aroma and gives you a better idea of what it would taste like when more mature. In the case of artificial oaking, I found it is essential to impart the whole range of it's flavours to oxidize the spirit just after (or preferably during) spicing. I use a beer carbonating stone and an oxygen concentrator for this but I know that an aquarium stone and air pump does the same job, and if you don't have them just splashing the liquor around two containers should do the job.
Maurice writes about some older techniques ...
....here's something I read in a book called "The Manufacture of Spirit as Conducted in the Distilleries of the UK" by J.A.Nettleton, 1893......
On the maturation of whisky...The raw spirit is placed in a tall cylinder and a currant of air or oxygen under pressure of one or two atmospheres, is forced through the spirit. The operation extending intermittently for ten days. The raw spirit is alleged to acquire a mellowness of three to five years bonding. These process help to rid the whisky of off flavours and helps smooth the taste....
The new whisky is placed in a small vat and alternate currants of hot and cold air are passed through. Both during and after the aeration a little sherry or similar wine is added to the spirit, and so are minute quantities of sulphuric acid or pottasic hydric sulphate. The latter in view of intensifying the action of the wine. The whole of the mineral acid and of the salt is afterwards removed by the addition of a small quantity of powdered and slaked lime, and the whisky then removed from the small sediment which occurs.
Les concurs ...
Following comment by Maurice I discovered reference in Linchines book of world wines reference to the use of sherry to soften taste and add aroma.
Have been using good quality chestnut teal sherry (medium sweet) 75ml to a litre of spirit and the results have been good. The recipe was Country Squire 2000 and SU Mc Gregors concentrate plus a little corn syrup. Its worth a try, does well in blind tastings
Another simple trick is to use corks in your bottles, rather than screw-caps. This helps the spirits breath a little, and help its aging. Jack explains ...
it's been a proven fact (discovered by rum distillers) for years- carbonic acid gasses formed in the mash, then carried over in the distillate, are capable of staying in solution, and causing a noticable sharpness - a period of "breathing" (typically 30 days) can allow this gas to escape.
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