Sunday, November 21, 2010

Slow cooker mashed potatoes recipe (with roasted garlic version!)

This is sooooo easy! If you've ever tried wrangling a pot of boiling water big enough to cook potatoes for this number of people then you are going to love this.

This is also a huge amount of food so do scale down if you have anything less than a 6 litre/quart slow cooker. Or if there are only two of you eating. Such as the time I cooked this when I was heavily pregnant and was overcome with that hormonal nesting instinct you get in the last few days....but that's a story for another time.

We had this for our Thanksgiving dinner last night (given we're British anyway, celebrating Thanksgiving a few days early doesn't really bother us too much). I've written over on my other blog why on earth a British family with no obvious American connections should celebrate Thanksgiving. But may I say this is a great way to destress your Thanksgiving cooking. I may not be American, but this is about the10th Thanksgiving dinner I've hosted and it was definitely the easiest, mainly down to this dish. (I'll also post the delectable slow cooker stuffing this week - Brits take note for Christmas!).

Ingredients for 12-16, depending on how many other dishes are being served:

2.5 KG or 5 lbs potatoes. I used Maris Piper
220 g or 1 cup butter (don't faint - there's a lot of potato here), cubed
240 ml or 1 cup water
salt and pepper to taste
half a head of garlic (optional)


Cube the potatoes, without peeling (seriously, the skins just melt away somehow cooked this way). The cubes don't need to be too exact - mine where about 2 cm or just over half an inch at maximum thickness.

Put the potatoes in the slow cooker with the butter, water and salt and pepper. Mix gently with your hands so the butter and seasoning disperse nicely.  If you are making the roasted garlic version, which I totally recommend if it balances with your meal, then wrap the garlic, unpeeled, in a small piece of tin foil so that it's nice and sealed in but has a little air around it. Pop this little package on top of the potatoes and put the lid on. Cook on High for 4 hours.

After 4 Hours, open the little garlic parcel, if using, and squidge (that's a technical term) the gooey garlic innards right on top of the potatoes, ready to be mashed in. You probably won't even need to snip the ends off the garlic cloves to do this. Then mash the potatoes to your desired and traditional-to-your-family level of lumpiness or smoothness.

The potatoes will happily sit like this on Low for at least 2-3 hours more so you can really work this around your day well. However, if they're to be left a lot longer, you may need to mash in a little warmed milk at the end before serving. Ours were perfect without after an hour on Low. I also really like my plain mash with some grated nutmeg but not if they're garlicky.


Great taste, super-convenient and made a TON of food! I will always make large-scale mashed potato this way from now on. We often cater for the masses so this was a great find. Use leftovers to top shepherd's pie or fish pie, make potato soup with, thinned down with some stock or you can add it to muffin mix (although NOT with garlic in! to make really moist muffins. Replace up to a cup of flour with the mash.

If you're looking for further Thanksgiving inspiration, try the Ultimate Recipe Swap over at Life As Mom


  1. I tried this tonight and am not sure where i went wrong! I used half quantities and put it all in my slow cooker and left it for just under four hours on high. When I came home from kid's ballet, it had burnt around the edges. I had to take it out of the slow cooker to mash it and needed to add extra milk. The potato had gone slightly caramelised. Have you ever tried smaller quantities? I'm wondering if I should have a) added more water, b) cooked it for a shorter time and c) not been out at the end of cooking time!!

  2. Hi Roseherbalist.
    First of all, I'm so sorry your dinner was spoiled. You don't need that at the end of a long day!
    Funnily enough, I was going to experiment with a smaller amount yesterday but we were rushing about and it didn't happen. However, I think it's the timing that's the issue. The huge 5 lbs of spuds I used at Thanksgiving would have taken a long time to heat through before they even started to cook so I think a much smaller amount would need less time for sure. The liquid level is fine, I promise - I think yours dried out because it overcooked.
    The other thing which may need fine-tuning is that your slow cooker may, especially if it's a big, modern one, be a bit more powerful than mine. However, it wouldn't make that much difference.
    I'll let you know when I sort this one out but if you try it again, maybe check after 2 hours? You can always switch it to Warm at that point if it's done. So sorry this didn't work for you this time.

  3. Thanks! I think you're right, it probably was the time. I don't think that my cooker is that zippy - I have two and the one I used for this was my old 3.5 litre cookworks one which I've used for years. Au contraire, I've recently invested in a 6.5 litre breville (was on special offer in sainsbury's after Christmas and I tought would be useful for chickens) which is alarming me because it seems so fierce in comparison with the other one. I was actually wondering if it was faulty or whether it's just that it's new?! I cooked a pot roast in it at the same time as the potatoes. The pot roast was supposed to be in for 3 hours on high but it was going so hard that I turned it down after 1 hour to low and even at that temp it seemed to be bubbling a lot... hmm. Have you had that experience with bigger/different slow cookers? Would also love to pick your brain about rice cookers at some stage as mine just doesn't seem to behave in the way you described yours did!! BTW - thank you for blogging, this has reinvigorated my enthusiasm for slow cooking!!

  4. Yes, I found the same. My big slow cooker is a Breville and I found it quite scary at first! It's not always easy if you're cooking two things but I always try and match the volume to the slow cooker as carefully as I can and that seems to help. I think the big ones are more powerful otherwise really big batches (e.g. bolognese for 10 which I did - x5! - for my daughter's Christening) would just never cook. I'm sure you'll soon get used to it. When I find the time (ha ha!) I want to add a tab on the blog about choosing a good slow cooker - mostly I think allow about a Litre or Quart per portion so if you regularly cook for 6, say, (or like to cook for 3 meals for two adults as I often do), a 6 litre is perfect but it needs less time if you cook for 4.
    As for rice cookers, I've only ever owned one, a complete cheapo, and we just follow the directions so I'm no expert...I bet there's someone out there with a rice cooker blog though! I hear you can even make chocolate cake in them!
    Glad you're finding the recipes useful. Some good ones cooked this week so I'll get them up there!