Barrel evaporation

[mjleslie]

Bought a used 6 gal red wine barrel for ageing sours. After about a week I finally got the thing rehydrated and holding liquid. Now I've got an Oude Bruin in there and all seems in good working order.

I'd like to understand more about the evaporation in a small barrel. I know it is faster than a larger barrel but how much faster? Does anyone have a rough idea say as a % loss per month? The barrel is in a relatively cool room with no direct sunlight. I really just want to know if I can leave it for a year and not worry about losing half my batch!

The winemaker I bought it from said he tops his up with finished wine every couple weeks to minimize head space. Is this typical practice for barrel aged beers?

 

[youreanimpulse]

Wax most of the barrel. Oxygen pickup is your enemy. You also may get too much oak on such a small barrel, especially at first. I would probably only keep beers in there a few weeks at first and age in carboys after that. Once you're aging longer periods in that barrel you can top up with beer or wort but shouldn't have to do it very often.

 

[adiochiro3]

I have a 7 gallon bourbon barrel, and I find I have to add about 6-8 oz./month to replace the "angel's share" and my 2-4 oz. taster samples. I usually sample ~1x/month to check progress and then top up. I'm in The People's Republik of Kalifornia, so my climate is pretty dry. I suppose a more humid climate might have slower loss rate. YMMV, but at least you now have some idea of what to expect.

When I bought my barrel, my LHBS owner told me to brew an extra gallon and keep it for topping up through the aging process. That works well for me. I always taste-test my top up supply to make sure it is not going to introduce something funky to my brew (I don't make sours, so I don't want funk )

As I understand it, slowly oxidizing your beer or wine is part of the desired purpose/result of aging in oak barrels. Think of it like headspace in a regular secondary fermenter; you want to keep it to a minimum so that oxidation is minimized. The reason to top it up through the barrel aging process is to keep the oxidation at an appropriate rate. For my purposes, I would not wax the barrel.*

*Disclaimer: I am ingnorant when it comes to making sours, so the information may or may not apply in aging sours.

Topping up will also keep your barrel properly hydrated and tight.

So to answer your main question: I would not just leave my barrel unattended for a year. Wine and spirits makers check progress by tasting, topping up, cycling barrels from the top of the warehouse to the bottom, etc. A little maintenance is a good idea. Besides -- it's fun to experience the development of your brew.

Two more thoughts:

1. Makes sure primary fermentation is complete before racking into your barrel.
2. If you top up, try not to fill it so that the liquid touches the base of the bung. Mine wicks up and bubbles out the edges and makes a tiny mess. Not a huge problem, but I don't want to attract ants or such if possible.

 

[Xpertskir]

Wax most of the barrel. Oxygen pickup is your enemy. You also may get too much oak on such a small barrel, especially at first. I would probably only keep beers in there a few weeks at first and age in carboys after that. Once you're aging longer periods in that barrel you can top up with beer or wort but shouldn't have to do it very often.

This and the amount of time your beer is going to stay in a barrel of that size is going to be measured in weeks not months.

FWIW small barrels are generally a waste and do not create a worthwhile product without a ton of extra "fixes". Get yourself a full size barrel, make your life easier, and get more beer for your effort.

Surprisingly the cost of a full size barrel is pretty equivalent to a small one.

 

[Wahoo]

Just to present the opposing viewpoint, I find that small (5 to 15 gallon) barrels are a significant upgrade for making sours vs just fermenting them in glass. To each their own. I wouldn't trade my selection of small barrels for a single full-sized one. And there's no way I could make enough beer for multiple large barrels.

I'd like to know where you got a 6 gallon wine barrel! In my experience only distilleries use the small barrels, I haven't found a winemaker that uses anything that small.

 

[WI_Wino]

Just to present the opposing viewpoint, I find that small (5 to 15 gallon) barrels are a significant upgrade for making sours vs just fermenting them in glass. To each their own. I wouldn't trade my selection of small barrels for a single full-sized one. And there's no way I could make enough beer for multiple large barrels.

I'd like to know where you got a 6 gallon wine barrel! In my experience only distilleries use the small barrels, I haven't found a winemaker that uses anything that small.

6 gallon barrels are common for home winemakers as the wine kits generally make 6 gallons.

http://www.vadaiwinebarrels.com/

http://home-brewing.northernbrewer.com/search?asug=&view=grid&w=barrel

 

[Wahoo]

When I think "wine barrel" I think of a barrel that has been used to make wine. Those in the link above are virgin barrels... the OP indicated that he bought a used red wine barrel.

 

[mjleslie]

I have a 7 gallon bourbon barrel, and I find I have to add about 6-8 oz./month to replace the "angel's share" and my 2-4 oz. taster samples. I usually sample ~1x/month to check progress and then top up. I'm in The People's Republik of Kalifornia, so my climate is pretty dry. I suppose a more humid climate might have slower loss rate. YMMV, but at least you now have some idea of what to expect.

When I bought my barrel, my LHBS owner told me to brew an extra gallon and keep it for topping up through the aging process. That works well for me. I always taste-test my top up supply to make sure it is not going to introduce something funky to my brew (I don't make sours, so I don't want funk )

As I understand it, slowly oxidizing your beer or wine is part of the desired purpose/result of aging in oak barrels. Think of it like headspace in a regular secondary fermenter; you want to keep it to a minimum so that oxidation is minimized. The reason to top it up through the barrel aging process is to keep the oxidation at an appropriate rate. For my purposes, I would not wax the barrel.*

*Disclaimer: I am ingnorant when it comes to making sours, so the information may or may not apply in aging sours.

Topping up will also keep your barrel properly hydrated and tight.

So to answer your main question: I would not just leave my barrel unattended for a year. Wine and spirits makers check progress by tasting, topping up, cycling barrels from the top of the warehouse to the bottom, etc. A little maintenance is a good idea. Besides -- it's fun to experience the development of your brew.

Two more thoughts:

1. Makes sure primary fermentation is complete before racking into your barrel.
2. If you top up, try not to fill it so that the liquid touches the base of the bung. Mine wicks up and bubbles out the edges and makes a tiny mess. Not a huge problem, but I don't want to attract ants or such if possible.

Some good feedback, thanks.

You have a good point about topping up to keep the barrel fully hydrated. That alone is reason enough to keep it full. I'm in a more humid climate so I should expect similar, if not less, rate of evaporation. I can live with adding a couple oz per month.

I certainly don't want to eliminate flow of oxygen. Part of my intention with buying the barrel is to allow acetic acid accumulation to closer represent Flemish ales. Also to build a little colony of microbes for future sours. The barrel is well used so I suspect to impart more wine flavour then oak. It's easy for me to sample and then rack into a carboy when the acidity or oak become strong. My only real concern here is loss and controlling the rate of acid production.

This leads into my next question about what actually happens to the content of the beer during evaporation... I understand that alcohol and water evaporate at different rates/temperatures (this is how distilling works). So would your ageing beer be getting less alcoholic, more alcoholic, or stay the same as the angels take their share? I think the answer to this helps with the question of what should you use to top it up: wort, water or beer?

I realize that in practice this is probably irrelevant. More just curious if this is something you seasoned barrel users think about.

 

[mjleslie]

Just to present the opposing viewpoint, I find that small (5 to 15 gallon) barrels are a significant upgrade for making sours vs just fermenting them in glass. To each their own. I wouldn't trade my selection of small barrels for a single full-sized one. And there's no way I could make enough beer for multiple large barrels.

I'd like to know where you got a 6 gallon wine barrel! In my experience only distilleries use the small barrels, I haven't found a winemaker that uses anything that small.

I'm in the same boat. There is no way I have the space nor the production capacity to fill a standard barrel.

Here's a pic of the barrel. I bought it from a ubrew winery down the road from me. I'm in Vancouver and I'm pretty sure it came from barrel-maker form the Okanogon.

 

[Wahoo]

that's pretty sweet. My biggest challenge with the small barrels I've been able to source is that they are spirit barrels-- which is good for making imperial stouts, but not so good for sours... at least at first.

 

[adiochiro3]

Some good feedback, thanks.

This leads into my next question about what actually happens to the content of the beer during evaporation... I understand that alcohol and water evaporate at different rates/temperatures (this is how distilling works). So would your ageing beer be getting less alcoholic, more alcoholic, or stay the same as the angels take their share? I think the answer to this helps with the question of what should you use to top it up: wort, water or beer?

I realize that in practice this is probably irrelevant. More just curious if this is something you seasoned barrel users think about.

You're welcome. I just topped up my barrel last weekend, so your timing was perfect.

All I can add to your "next question" is that I was surprised to find that my Black Pearl Porter gravity had dropped from 1.024 to 1.012 over the three months it's been in the barrel. 1.024 is the approximate expected FG for the recipe (it has lactose added), so I considered primary fermentation complete. I brewed another batch that will not age in the barrel, and it finished at 1.024 after a month in the primary -- so I'm doubly confident in the FG.

I've thought about it this week & either fermentation continued in the secondary, or the beer stratified and the sample I took was not representative of the whole. The second thought is my bet -- I took the sample from the top.

 

[mjleslie]

That's an interesting observation for sure.

I guess it could be attributed to a Brett infection in the barrel which would consume more of the complex sugars you intended to leave behind with a clean fermentation.

So you are topping off with already fermented beer and not wort? I wonder if this makes any difference. I didn't have the foresight to brew an extra gallon for topping up so I might do that this weekend.

I was thinking I could freeze the wort in small batches and thaw as needed. Then as I add the wort I would be giving the yeast a little pick-me-up every month or so. It would be a similar effect to adding fruit later in ageing.

I've considered just topping up with malt extract to make life easier - this shouldn't have too much of an impact on the final product right?