Making Ice Wine

[Tim F]

I made a sweet muscat last year for the missus but in the end I got the sweetness she wanted by just back sweetening with sugar and using potassium sorbate to stop the added sugar fermenting out. She liked it (tho too sweet for my tastes) but it feels like cheating to do it that way

This year I'm making her an ice wine. Obviously I can't pick frozen grapes so I am freezing the juice, then straining out the water crystals to concentrate it, then fermenting with BV7, a lower alcohol yeast.

Started on Sat by picking 200kg of Semillon from the Barossa for 10c/kilo (!). My son came along for his first ever harvest too, start em early I reckon Grapes were maybe not quite as ripe as I hoped coming in at about 12.5Be & pH 3.26 but I'll be concentrating the juice anyway so should be right.





Crushed and left on the skins for a few hours and then pressed ~120L juice. That went into buckets in the chest freezer with the controller set to -6.



Today I am starting to see big clear ice crystals forming round the edges, so it seems to be working as planned. I'm still not sure if it will be better to sieve out the crystals as they form or just strain the lot out in a bucket with holes when the whole lot turns to slush.

 

[joshuahardie]

Subscribed. This looks really interesting.

Is there a reason to concentrate the juice before fermentation, compared to after like you would if doing an Eisbock

 

[Rina]

Might this be illegal?

 

[Philthy79]

Might this be illegal?

Why?

 

[Tim F]

Might this be illegal?

Nope. It's not illegal to concentrate fruit juice and it's not illegal to ferment concentrated fruit juice.
Joshua if you concentrated after fermentation you'd get double the alcohol - this way you just get twice the sugar concentration. The yeast eats sugar till it can't tolerate any more alcohol and then stops, leaving lots of residual sugar.

 

[Bugglz]

Might this be illegal?

No as it is sugar, not alcohol that is being concentrated. If the wine was fermented and then the water frozen off (freeze distilling) it would be illegal.

 

[sim]

ice "distillation" is illegal in canada i think, although that is not whats going on here. I gather Tim F is starting with a higher gravity so the yeast conks out when the alcohol gets up there and leaves some sweetness. As apposed to fermenting then freezing and removing water to concentrate the alcohol content - which in some places counts as distillation.

wow totally beatin to it

 

[manticle]

Might this be illegal?

Don't you think he paid for the grapes?

 

[Rina]

Carry on

 

[Malted]

Looking forward to updates on how this goes Tim.

 

[Tim F]

I just went out and checked it and -6C may be a little too low - there are heaps of clear water crystals in a slurry in the middle but it is frozen solid about 40mm all round the outside. I'm not sure if that is all water too or if some of the sugars are frozen in there so backed it off to -3C to see if I can get a nice consistent slurry. It definitely works though - I took out a cup of slurry and sat it in a sieve for a minute and collected this intense syrup - and only watery tasting ice left behind.

 

[Dave70]

I know sounds stupid before I say it, but could you get the desired result by using one of those slushie machines?
A mate hired one for a party and I stood there thinking about tipping beer in there to produce an Eisbock.
Would have been more palatable than the orrible pink **** they were making with it.

 

[Tim F]

I like it only concern might be oxidation? Cold liquid absorbs gas more readily and if it is constantly churning might not be good.

 

[drsmurto]

I like it only concern might be oxidation? Cold liquid absorbs gas more readily and if it is constantly churning might not be good.

Nothing a healthy level of free SO2 can't prevent

 

[Tim F]

Imagine visiting a winery and seeing a row of slushy machines churning away...

I strained the juice tonight - used 2 buckets from Bunnings one on top of the other, with holes drilled in the bottom of the top one. Smashed up the ice as much as possible and tipped into the top bucket. I got roughly 50% of the starting volume but probably didn't concentrate it by 50% as the leftover ice still tasted sweetish. I am going to refreeze the left over ice slurry and strain it again. Still I got ~60L juice at around 1.130 which will finish around 1.050 with a 13% alcohol tolerant yeast. I filled up a few cubes with the juice and they are stored in the freezer for a few days until my fermenter is free.

Here's the slurry straining in the bucket:

 

[Dave70]

My wife brought back a bottle of ice wine from Germany a few years back. It was supposed to be high end (ish) stuff but man, it was just so sweet I could hardly finish a glass.
I figured it had to be back sweetened. Either that or they know some funky tricks with getting the ABV - it was about the 14% mark I think - high and still retaining the characteristic desert wine sweetness.
What are your plans for this one? Just going off some of the cider's I've knocked out, ethanol tolerant yeasts always finish really dry. Not exactly what you'd want in a desert wine I guess.
Is this the same with grape juice concentrate?

 

[MHB]

Making Ice Beer/Cider I got best results by making sure the freezing was very slow. The slower you drop the temperature, the bigger the ice crystals, the easier to separate and the more juice you recover from the mixture. Cool too fast and you end up with a slushy and a lot of retained juice.
Ended up sealing the beer in a barrier bag, packing the bags in a Styrofoam box (Broccoli Box) putting the box in the freezer. To separate hang the bag inside a refrigerator that has been turned right down (about -2oC IIRC) and cut one corner off the bag, worked very well, got some cider up to 35% - this was post fermentation but the same principles apply.
Mark

I love German and Austrian Ice Wines even go the odd Trockenbeerenauslese but you really need to cellar them for a couple of decades to get the real value from them, young the sweetness rules with age they get incredibly intense and complex
M

 

[Tim F]

Great tip, cheers. I think I did go a bit fast this time. I saved all the ice so might try straining it again in the freezer on near 0.

 

[raven19]

Tim, I hope you can make the case swap at my place week after Easter, its just around the corner from your place.

Feel free to bring some of this wine if its ready! (I presume it will need some serious time post ferment though...!)

 

[Muggus]

Imagine visiting a winery and seeing a row of slushy machines churning away...

I strained the juice tonight - used 2 buckets from Bunnings one on top of the other, with holes drilled in the bottom of the top one. Smashed up the ice as much as possible and tipped into the top bucket. I got roughly 50% of the starting volume but probably didn't concentrate it by 50% as the leftover ice still tasted sweetish. I am going to refreeze the left over ice slurry and strain it again. Still I got ~60L juice at around 1.130 which will finish around 1.050 with a 13% alcohol tolerant yeast. I filled up a few cubes with the juice and they are stored in the freezer for a few days until my fermenter is free.

Here's the slurry straining in the bucket:
View attachment 52886

Sounds pretty good mate. Might wanna keep the first runnings seperate, even if the icey slurry that you have left it still sweet. I could imagine the best flavour would come from the first runnings.
Have you got an ph/TA readings on the resultant juice? The acidity should have increased by a fair bit too.

I recall being told that figures of 10:10:10 for dessert wines (Sauternes/botrytis Semillon, etc) is a good guide to getting balance. In other words; 10B of residual sugar (~1.072), 10% alcohol, and 10g/L TA. Not sure how true that is, apparently Noble One has similiar sorts of figures (?), but 10B of residual is alot!