Keeping barrels warm

How do folks keep a few barrels (say, 6 barrels) warm, to allow ML to continue during chilly weather, without having the top barrels getting too warm and the bottom being too cool. I’m sure this was covered when ‘Goldilocks and the three bears’ was read to me as a kid, but I obviously wasn’t paying attention.

Fish tank heaters. Get them at any pet store. They work wonderfully.

A couple of low tech ways I’ve used…

  1. Electric Blankets…
  2. Tents ( or any kind of non flammable covering) with space heaters. ( we used the oil filled electric ones that look like radiators)

A couple years ago I ended up installing an actual heater in the barrel room, (since I don’t over vintage anymore) and that’s been working just fine, I just crank it up to 85 for a week or so after inoculating EnoFerrm Alpha.

I never had good luck with fish tank heaters, although a lot of people swear by them. I don’t like the thought of a cord and probe sticking out of the barrel.

The easiest and cheapest way I’ve warmed barrels is with a little $9.99 ceramic heater that I got at Walgreen’s, plus a tarp over the barrels. You just have to make sure the circuit you plug into won’t trip with the extra load. I’ve seen that happen a few times. Also, make sure the barrels aren’t topped completely before you start heating. It will be a big mess the morning after you start heating if you forget that part. Also, feel along the outside of the tarp to make sure you didn’t pull any bungs out while adjusting the tarp.

what’s your hurry?

I ask this because the earlier you sulphur the more you need to.

Make a small warm room with a heater and tent. I’ve done it with tank heaters as well but I don’t like the thought of how much of a difference in temp you get next to the heater vs. the rest of the barrel. Never tried the heating blankets.

Do be careful not to use wax/plastic tarps though. I’ve seen a near disaster happen at a former location because the tarp fell on the heater at night when no one was around.

Thanks for the excellent thoughts/suggestions.

The control of the fish tank heaters is appealing…but I agree with worrying about things sticking out of barrels, and about possibly overly high temps of the wine next to the heater.

Sounds like a tent is the way to go…suspected that. I probably will set up a temp conrtoller/thermistor located near the top, to keep things from getting too warm. Thanks for the warnings here…don’t want wine spilling out and would like to avoid burning anything down :slight_smile:. The electric blanket idea is appealing.

This is a 2014 Chardonnay (Sonoma Coast) that’s still plugging away at ML. The pH is 3.1 (picked at 22 brix), so ML hasn’t been the easiest. Fortunately it’s been slowly plugging away the entire time, so it’s nearing the finish line (and tastes extremely youthful). But obviously I can’t afford to have it get cold and stop now. It’s 61-62 degrees atm and moving along…maybe I’ll get lucky and it’ll stay there. But I’m not counting on that. I’ll be thilled if I can get them up to 65, without getting any barrels much higher than that.

Take them outside and let them bask in the sun, or re ambient temps too cold and end up negating that? Starting to warm a bit this week.

With fish tank heaters they are completely submersible. Only think coming out of barrel is the power cord. Bung goes back on. Another plus is you can set the temp on the heater to your liking.

FWIW, when I did use tank heaters I used ferm bungs where I cut one of the holes on the side and inserted the wire. That way you are not constantly blowing your bung off as the temp and ferm increases and you have a nice seal on the edges.

Thanks for the great suggestions.

I’ve considered taking the barrels outside…other than topping up and other sundry tasks tho, there’s not much for me to do right now so I’m not there enough for this to work.

I’m still nervous about using fish tank heaters, even tho I’ve used them in the past to great effect when doing small lot primary fermentations (esp half ton).

I’ve tented the barrels, and have a small heater connected to a temperature controller (probe at the top). So far so good.

I’ve used an aquarium heater in the past. The simplicity and efficiency in applying the heat directly where it needs to be is appealing to me. Evan’s warnings over tarps/tent material and space heaters is terrifying.

How do you avoid VA otherwise? Cold temps, topped barrels, and hope?
I know the old world often doesn’t complete MLF until the subsequent spring, but why endure the risk if you don’t have to?

Giant chickens?

I’m in the same boat with a small lot of sangiovese-- tenting, heater, stirring, etc. I also am anxious to wrap up the microbial part of the proceedings and would prefer not to let this stage drag on. I’m accustomed to pinot sailing thru MLF pretty smoothly, but this is the second year I’ve had the sangiovese struggle. Two of my five barrels were barreled down straight from the press pan, and they are doing much better than the others, which settled overnight before going to barrel. I’m using an oil filled radiator type, which seems safer than the alternatives, but I should probably add a small fan to even out the heat. I’ve moved temps up from 55F to about 66F so far, but I’m about 2 degrees warmer at the top of a two-high stack than at the bottom. It’s a big pain in the ass removing tarps to get into the barrels to take temps, measure pH, press my ear to the bung to listen for CO2 snapping, and to stir. I think that next year I would probably just rack the whole of a problematic lot back into tank and warm and monitor it all together rather than leave it in barrel.

I didn’t think gross lees were beneficial to MLF, and instead could result in some off aromas- curious those are further advanced.

How did the primary fermentation go on the sangiovese? I’ve never worked with that grape, but the one time I made syrah it was quite reductive, which could result in a slower MLF:

Take care of the yeast during the alcoholic fermentation (feed them and keep fermentation temperatures in line (below 85º F, 28º C), this limits their production of compounds that can later be possibly responsible for antagonizing the ML bacteria: H2S and VA, for example. Recent research shows that MLFs actually finish quicker and with less problems in wines made with yeast that are fed a complete set of nutrients during the alcoholic fermentation compared to those that are not. So remember: healthy yeast ultimately means healthy ML bacteria down the line.)

In this case, I chalk it up to more lees = more nutrient for the bacteria. If you’re worried about reduction, there are malo nutrients you can add instead of hanging onto a lot of lees. Syrah is more reductive than most (part of its appeal, in my opinion), and I haven’t had those sorts of issues with sangiovese, so I was less worried about trying gross lees here than I might have been with syrah. Since primary fermentation hasn’t been notably problematic with the sangio, I hadn’t thought about feeding it, but I hadn’t been thinking in terms of primary’s effect on MLF either. Food for thought. Thanks.

This may come as shocking to some - but loosen your bungs if you take your bbls outside. You’re not going to be out there babysitting them when they pop off due to expansion so give them some wiggle room before you leave them be.

A “warm room” is ideal - and you can makeshift one with 2 walls of bins stacked 3 high with a tarp thrown over and stretched out with the barrels in the middle. Leave a heater up front and in the back with a fan on for convection. I also recommend placing some empty racks on top of the top barrels (if they’re stacked) so you can give yourself a little work room for sampling the top barrels.

Also - leave a thermometer to keep an eye on the temp in the tent.

Not a bad idea during this time to scrub the area around the bunghole little more routinely then you normally would with a little sulfur citric. They’ll get a little scuzzy once they start to get active.

Must be luck I guess, been doing it that way for 20 years. I am good at cleaning…

There’s nothing wrong with just keeping it topped and monitoring every 2 weeks (or weekly if you have the means). If you’re not down with Primary or Malic by Christmas you probably won’t be done until March/April when the cellar starts to warm up again (this isn’t old world - this is Napa). There’s a time and place for creating a warming room / tent, or moving the barrels out into the sun, or just letting them go in the cellar at a slower rate. Anytime I ever had to insert hanging items like bags of yeast hulls that’s when you start to see spikes in VA as you’re inviting microbial growth.

Just let it ride unless it starts to get freaky. Take precautionary measures to help move them along with as minimal touching of the wine as possible.