Checking if maceration is complete

[Welshbrew]

Hello

I create my gin by macerating at room temperate for 7 to 10 days.

Up to now I have determined if maceration is done by taste and colour. Not exactly reliable. And certainly not a scale when I open my distillery.

Is there any equipment that will give me some exact figures of how the liquid has changed?

It starts as ethanol/water at 40% ethanol by volume. All solid ingredients are then added, before being removed before transferring to the still.

What about the Anton Paar density meters like the DMA 35?

Or should I be looking at a refractometer instead?

Thanks

[indyspirits]

Measuring completion is fraught with frustration.  Proof should generally not change. You'll have no sugar so measuring brix will lead nowhere.  Establish a recipe & testing protocol. Record copious notes. Distill until you're pleased with the product. Rinse. Repeat.

 

 

[Welshbrew]

I know the proof will not change.

Sugar will be very low, probably too low to measure.

Wonder if refractive index could be used?

[indyspirits]

Perhaps I don't fully understand what you're trying to accomplish.  My point is to ignore the measurement of anything other than botanical quantity per unit volume and a known proof.  Just create a recipe, document, and do it the same way each time. It doesn't matter if maceration is "done" (whatever that means) only that the resulting product is "good" (again, subjective).    If you concern yourself with this aspect of product development you'll want to get out the cat-o-nine-tails when you try to ramp up from 4 to 400 liters.

 

 

[Foreshot]

I don't believe that you're going to find that there is an objective and quantitative way to do want you want. Taste is the only way to go to get a consistent product. 

That being said you would probably have to do a multi factor analysis to get close: SG, pH, TDS, and any other test you think you can throw at it. It still might not provide anything useful. 

You may be able to do better if you did each botanical separate though I don't know if even that would do it. 

[Welshbrew]

19 hours ago, indyspirits said:

Perhaps I don't fully understand what you're trying to accomplish.  My point is to ignore the measurement of anything other than botanical quantity per unit volume and a known proof. 

The ethanol/water mixture takes time to take the flavour out of the solid ingredients.

After 1 day the flavour would be too weak to be worth distilling.

After 12 days it will be definitely ready.

Now it could be ready after 7 days. Or 8 days. That is what I want to measure instead of just waiting too long to be sure.

I reckon measuring electrical conductivity may work - it will give an indication of the number of ions dissolved in the liquid.

[JailBreak]

6 minutes ago, Welshbrew said:

The ethanol/water mixture takes time to take the flavour out of the solid ingredients.

After 1 day the flavour would be too weak to be worth distilling.

After 12 days it will be definitely ready.

Now it could be ready after 7 days. Or 8 days. That is what I want to measure instead of just waiting too long to be sure.

I reckon measuring electrical conductivity may work - it will give an indication of the number of ions dissolved in the liquid.

This is a little off topic but what kind of still do you use or how much is your botanical charge? With our gin I macerate for 18 hours before running through an alembic pot still and it is LOADED with flavor. In fact, I am looking to cut the botanical bill because I have been getting some louching problems.

I agree with Indy that your best bet is lots and lots of experimental runs with excellent documentation. Once you have a strict routine down, your product should turn out more or less the same each time. For further consistency you can continually blend batches.

[Welshbrew]

I'm using a copper alembic still.

Botanical charge is just over 30g per litre, at 40% ABV maceration.

I have pretty much nailed my recipe. This is at 10 litre testing size.

Problem is moving to 100 and 200 litre sizes. It will be much colder in January than July. The maceration will take longer due to the ethanol mix being colder.

This is what I want to measure. Establish a value when maceration is complete (conductivity, PPM, SG, refractive index) then test the maceration until complete.

Taste is not reliable. Fully stop.

[glisade]

2 hours ago, Welshbrew said:

Problem is moving to 100 and 200 litre sizes. It will be much colder in January than July. The maceration will take longer due to the ethanol mix being colder.

 

For partly this reason is why we don't macerate but put all botanicals in the kettle during distillation. Seasonal affects will be minimal with this method. Have you considered going with this method instead? Of course using a gin basket will get rid of seasonal affects as well but I doubt you could do that with your alembic still.

[PeteB]

The only way I know of reliably measuring what you are asking is with very expensive laboratory tests such as gas chromatography and mass spectrometery. Big distilleries develop recipes this way. Once the recipe is sorted they revert to measuring weights and time.

The measuring techniques you are suggesting just don't give you enough information. After a time your nose and pallet will be able to give you a very good indication of how your extractions are progressing. Great taste and smell is what you are trying to produce so those are the instruments you, as a craft distiller, should be using.

Also as mentioned in a post above, macerate and distil your botanicals separately then blend the spirit afterwards. This is a far easier way to get the flavour you want. Different sources of the same botanicals can release different amounts of flavours and also as you suggested, macerating at different times of the year.